Yearly Archives: 2016

Veeco Instruments Inc. (NASDAQ: VECO) announced today that Epistar Corporation (TSE: 2448) has ordered multiple TurboDisc EPIK 700 Gallium Nitride (GaN) Metal Organic Chemical Vapor Deposition (MOCVD) Systems for the production of light emitting diodes (LEDs). The Veeco systems will be used to meet demand for various applications.

“The improved demand of solid state lighting combined with the need to compete in a competitive market dictates we choose the most productive and most cost-efficient MOCVD platform in the industry,” said Dr. MJ Jou, President, Epistar Corporation. “Veeco has been our supplier of choice dating back to their innovative K465i system. After adopting their latest EPIK platform, we have achieved superior yield results and lowered manufacturing costs. The addition of these new EPIK MOCVD systems will help advance our production goals and improve our product competitiveness.”

Based on Veeco’s proven TurboDisc technology and the proprietary Uniform FlowFlange, the award-winning EPIK 700 MOCVD system enables customers to achieve an improved cost per wafer savings compared to previous MOCVD systems through improved wafer uniformity, reduced operating expenses and increased productivity.

“We believe that a leader such as Epistar ramping production to meet demand of LEDs is a positive sign for the industry as a whole,” said James T. Jenson, Senior Vice President, Veeco MOCVD Operations. “Veeco’s superior MOCVD technology is the number one choice of manufacturers looking for a competitive edge in a market that seems to be turning upward again. We look forward to supporting Epistar’s future MOCVD requirements as they continue their growth plans.”

Samsung Electronics Co., Ltd. this week introduced a blueprint for next-generation flash memory solutions that will meet the ever-increasing demands of big data networks, cloud computing and real-time analysis.

Samsung 32TB SAS SSD - world's largest capacity drive (Photo: Business Wire)

Samsung 32TB SAS SSD – world’s largest capacity drive (Photo: Business Wire)

At Flash Memory Summit 2016, held in the Santa Clara (CA) Convention Center, Samsung showcased its 4th generation Vertical NAND (V-NAND) and a line-up of high-performance, high-capacity solid state drives (SSDs) available for its enterprise customers as well as Z-SSD, a new solution providing breakthrough performance for flash-based storage.

Samsung’s new flash storage devices are expected to contribute significantly to the global IT industry in meeting the growing storage requirements of today’s enterprise computing environment. These solutions will accommodate enormous amounts of data, and extremely high-speed information processing, while enhancing the total cost of ownership (TCO) for data centers.

“With our 4th generation V-NAND technology, we can provide leading-edge differentiated values in high-capacity, high-performance and compact product dimensions, which together will contribute to our customers achieving better TCO results,” said Young-Hyun Jun, President of the Memory Business at Samsung Electronics. “We will continue to introduce more advanced V-NAND solutions and expand our flash business initiatives in maximizing an unbeatable combination of performance and value.”

Samsung’s 4th Generation V-NAND stacks 30 percent more layers of cell-arrays than its predecessor

Samsung introduced its 4th generation, 64-layer triple-level-cell V-NAND flash memory that pushes the envelope of NAND scaling, performance and storage capacity. Stacking 64 layers of cell-arrays, the new V-NAND can increase its single-die density to an industry-leading 512Gb and its IO speed to 800Mbps. Starting in August 2013, Samsung has previously introduced three generations of “industry-first” V-NAND products with 24, 32 and 48-layer vertical cell-array stacking technologies.

Samsung plans to provide the world’s first 4th generation V-NAND flash memory products in the fourth quarter of this year, which will help manufacturers to produce faster, more stylish and portable computing devices, while offering consumers a more responsive computing environment.

World’s largest capacity drive − 32TB SAS SSD − for enterprise storage systems

Samsung’s latest Serial Attached SCSI (SAS) SSD is the world’s largest single drive ever introduced to the industry based on 512-gigabit (Gb) V-NAND chips. A total of 512 V-NAND chips are stacked in 16 layers to form a 1-terabyte (TB) package and the 32-terabyte (TB) SSD contains 32 of those packages.

By adopting a new 4th generation V-NAND design, the 32TB SAS SSD can reduce system space requirements up to 40 times compared with the same type of system using two racks of hard disk drives (HDDs). The 32TB SAS SSD will come in a 2-5-inch form factor and be produced in 2017. Samsung also expects that SSDs with more than 100TB of storage capacity will be available by 2020, thanks to continued refinement of V-NAND technology.

1TB memory in a single BGA package

The Samsung 1TB BGA SSD features an extremely compact, ball grid array (BGA) package design that contains all essential SSD components including triple-level-cell V-NAND flash chips, LPDDR4 mobile DRAM and a state-of-the-art Samsung controller.

It will deliver unprecedented performance, reading sequentially at 1,500MB/s and writing sequentially at 900MB/s. By reducing its size up to 50 percent compared to its predecessor, the SSD weighs only about one gram (less than half the weight of a U.S. dime), making it ideal for ultra-compact next generation notebooks, tablets and convertibles.

Next year, Samsung plans to launch its 1TB BGA SSD by adopting a high-density packaging technology called “FO-PLP (Fan-out Panel Level Packaging)” which Samsung Electronics developed with Samsung Electro-Mechanics.

New ‘Z-SSD’ breaks through performance limits of current NAND flash memory storage

Samsung has also developed a high-performance, ultra-low latency SSD solution, the Z-SSD. Samsung’s Z-SSD shares the fundamental structure of V-NAND and has a unique circuit design and controller that can maximize performance, with four times faster latency and 1.6 times better sequential reading than the Samsung PM963 NVMe SSD.

The Z-SSD will be used in systems that deal with extremely intensive real-time analysis as well as extending high performance to all types of workloads. It is expected to be released next year.

ChipMOS TECHNOLOGIES (Bermuda) LTD. (Nasdaq:  IMOS), a provider of outsourced semiconductor assembly and test services, today announced that its shareholders have approved the merger of ChipMOS with and into ChipMOS TECHNOLOGIES INC. (Taiwan Stock Exchange: 8150), a company limited by shares incorporated under the laws of the Republic of China and a 58.3% directly owned subsidiary of ChipMOS as of January 21, 2016, with ChipMOS Taiwan being the surviving company after the Merger at ChipMOS’s annual general meeting of shareholders (the “Annual General Meeting”) held today.  It was announced that 83.41% of the outstanding shares ChipMOS were voted in favor of the Merger (1.03% of the outstanding shares of ChipMOS were voted against the Merger, 0.44% abstained, and 15.12% did not vote).  In addition, 83.66% of the outstanding shares ChipMOS Taiwan were voted in favor of the Merger at the ChipMOS Taiwan Extraordinary General Meeting, which was also held today (0.0% of the outstanding shares of ChipMOS were voted against the Merger, 5.84% abstained, and 10.50% did not vote). Both ChipMOS and ChipMOS Taiwan expect to close the Merger by October 31, 2016.

In connection with the Merger, the Annual General Meeting has also approved (i) the Agreement and Plan of Merger dated January 21, 2016 (the “Merger Agreement”) by and between ChipMOS and ChipMOS Taiwan and the transactions contemplated therein, (ii) the statutory merger agreement between ChipMOS and ChipMOS Taiwan (the “Bermuda Merger Agreement”) and the transactions contemplated therein and (iii) ChipMOS’s adoption of the Merger Agreement and the Bermuda Merger Agreement, and has authorized any one or more of the directors of ChipMOS to execute and deliver documents on his behalf and on behalf of ChipMOS in connection with, and to do all things necessary to give effect to, the Merger, the Merger Agreement, the Bermuda Merger Agreement and the matters contemplated thereby.

All other proposals at the Annual General Meeting were approved by the ChipMOS shareholders, including the re-election to the Board of Directors of ChipMOS (the “Board”) of Messrs. John Yee Woon Seto, Chao-Jung Tsai and Rong Hsu, as directors for three-year terms; and the re-appointment of PricewaterhouseCoopers, Taiwan, as the independent auditors of ChipMOS, to hold office until the close of the next annual general meeting, and the authorization of the Board to determine their remuneration.

S.J. Cheng, Chairman and Chief Executive Officer of ChipMOS and ChipMOS Taiwan, commented, “Today’s overwhelmingly positive vote is a strong endorsement of the strategic rationale and potential cost savings to the Company. We are very excited to be near the end of our multi-year corporate streamlining process. We will now work to secure the two approvals required in Taiwan, as we have already received necessary approvals by the U.S. Securities and Exchange Commission and Bermuda authorities. Our goal is to now finalize the merger on an accelerated schedule by October 31, 2016. Importantly, we will be moving forward as a unified, more efficient company with diverse and compelling near and longer term growth opportunities.”

Cypress CEO and President Hassane El-Khoury

Cypress CEO and President Hassane El-Khoury

Cypress Semiconductor Corporation (NASDAQ:  CY) today announced that Hassane El-Khoury has been named its president, chief executive officer, and a member of its board of directors, and that Ray Bingham’s current role as chairman of the board has been expanded to executive chairman, providing him with a day-to-day role in support of the CEO focused externally on customers and investment opportunities.

“The goal of our comprehensive internal and external executive search was to identify a CEO who would drive the transformation of Cypress, expand our leadership position in embedded systems and enhance our focus on revenue and earnings growth and long-term shareholder value,” said Bingham, a 30-year veteran of the semiconductor industry who sits on numerous high-tech boards of directors in addition to Cypress. “Among the many interested and qualified candidates we interviewed, El-Khoury emerged as the clear executive leader to deliver on Cypress’s enormous potential and unlock its value for customers and investors. He has demonstrated strong leadership and judgment over the past nine years as a senior executive at Cypress, heading up some of the company’s most innovative and successful businesses. He is an agent of change who brings to this position an extensive knowledge of our target markets and a mindset focused on customer value and profitable growth.”

“Cypress is at an inflection point,” said El-Khoury, who played a key role in Cypress’s successful integration with Spansion over the last year and a half and its more recent acquisition of Broadcom’s Internet of Things (IoT) business. “We’ve architected our company to become more valuable to our embedded-systems customers, significantly expanding our portfolio of high-value solutions in growth markets such as automotive, industrial, consumer electronics and the IoT. I am thrilled and humbled to lead Cypress into the future as we expand upon our position as the supplier of choice for the world’s most innovative embedded-systems customers and partners.”

Before joining Cypress in 2007, El-Khoury served in various roles with Continental Automotive Systems in the U.S., Germany and Japan. Prior to Continental, he earned his bachelor’s of science degree in electrical engineering (BSEE) from Lawrence Technological University in Michigan and his master’s degree in engineering management from Michigan’s Oakland University.

Bingham served as the non-executive chairman of Cypress’s Board of Directors from its merger with Spansion in March 2015 to the present. He serves on the boards of high-tech companies including Oracle Corporation, he is the chairman of the board of Flex (formerly Flextronics), and he has served as the managing director of General Atlantic LLC, a technology-focused global private investment firm with offices in Silicon Valley. From 1993-2005, Bingham served in leadership positions with Cadence Design Systems, Inc., including president and chief executive officer and executive chairman. His executive experience provides Cypress with the critical perspective of someone familiar with all facets of an international enterprise.

Concurrent with these changes, as planned, former Cypress CEO T.J. Rodgers has resigned from Cypress and the Cypress board. “T.J. created a company with the resiliency to stand up to more than 34 years of change in the semiconductor industry, and one that is positioned for considerable future success,” El-Khoury said. “On behalf of all of our employees around the world, we would like to thank T.J. for his contributions and dedication to Cypress.”

Unique optical features of quantum dots make them an attractive tool for many applications, from cutting-edge displays to medical imaging. Physical, chemical or biological properties of quantum dots must, however, be adapted to the desired needs. Unfortunately, up to now quantum dots prepared by chemical methods could be functionalized using copper-based click reactions with retention of their luminescence. This obstacle can be ascribed to the fact that copper ions destroy the ability of quantum dots to emit light. Scientists from the Institute of Physical Chemistry of the Polish Academy of Sciences (IPC PAS) in Warsaw and the Faculty of Chemistry of the Warsaw University of Technology (FC WUT) have shown, however, that zinc oxide (ZnO) quantum dots prepared by an original method developed by them, after modification by the click reaction with the participation of copper ions, fully retain their ability to emit light.

“Click reactions catalyzed by copper cations have long attracted the attention of chemists dealing with quantum dots. The experimental results, however, were disappointing: after modification, the luminescence was so poor that they were just not fit for use. We were the first to demonstrate that it is possible to produce quantum dots from organometallic precursors in a way they do not lose their valuable optical properties after being subjected to copper-catalysed click reactions,” says Prof. Janusz Lewinski (IPC PAS, FC WUT).

Quantum dots are crystalline structures with size of a few nanometers (billionth parts of a meter). As semiconductor materials, they exhibit a variety of interesting features typical of quantum objects, including absorbing and emitting radiation of only a strictly defined energy. Since atoms interact with light in a similar way, quantum dots are often called artificial atoms. In some respects, however, quantum dots offer more possibilities than atoms. Optical properties of each dot actually depend on its size and the type of material from which it is formed. This means that quantum dots may be precisely designed for specific applications.

To meet the need of specific applications, quantum dots have to be tailored in terms of physico-chemical properties. For this purpose, chemical molecules with suitable characteristics are attached to their surface. Due to the simplicity, efficacy, and speed of the process, an exceptionally convenient method is the click reaction. Unfortunately, one of the most widely used click reactions takes place with the participation of copper ions, which was reported to result in the almost complete quenching of the luminescence of the quantum dots.

“Failure is usually a result of the inadequate quality of quantum dots, which is determined by the synthesis method. Currently, ZnO dots are mainly produced by the sol-gel method from inorganic precursors. Quantum dots generated in this manner are coated with a heterogeneous and probably leaky protective shell, made of various sorts of chemical molecules. During a click reaction, the copper ions are in direct contact with the surface of quantum dots and quench the luminescence of the dot, which becomes completely useless,” explains Dr. Agnieszka Grala (IPC PAS), the first author of the article in the Chemical Communications journal.

For several years, Prof. Lewinski’s team has been developing alternative methods for the preparation of high quality ZnO quantum dots. The method presented in this paper affords the quantum dots derived from organozinc precursors. Composition of the nanoparticles can be programmed at the stage of precursors preparation, which makes it possible to precisely control the character of their organic-inorganic interface.

“Nanoparticles produced by our method are crystalline and all have almost the same size. They are spherical and have characteristics of typical quantum dots. Every nanoparticle is stabilized by an impermeable protective jacket, built of organic compounds, strongly anchored on the surface of the semiconductor core. As a result, our quantum dots remain stable for a long time and do not aggregate, that is clump together, in solutions,” describes Malgorzata Wolska-Pietkiewicz, a PhD student at FC WUT.

“The key to success is producing a uniform stabilizing shell. Such coatings are characteristic of the ZnO quantum dots obtained by our method. The organic layer behaves as a tight protective umbrella protecting dots from direct influence of the copper ions,” says Dr. Grala and clarifies: “We carried out click reaction known as alkyne-azide cycloaddition, in which we used a copper(l) compound as catalysts. After functionalization, our quantum dots shone as brightly as at the beginning.”

Quantum dots keep finding more and more applications in various industrial processes and as nanomarkers in, among others, biology and medicine, where they are combined with biologically active molecules. Nanoobjects functionalized in this manner are used to label both individual cells as well as whole tissues. The unique properties of quantum dots also enable long-term monitoring of the labelled item. Commonly used quantum dots, however, contain toxic heavy metals, including cadmium. In addition, they clump together in solutions, which supports the thesis of the lack of tightness of their shells. Meanwhile, the ZnO dots produced by Prof. Lewinski’s group are non-toxic, they do not aggregate, and can be bound to many chemical compounds – so they are much more suitable for medical diagnosis and for imaging cells and tissues.

Research on the methods of production of functionalized ZnO quantum dots was carried out under an OPUS grant from the Poland’s National Science Centre.

The year 2016 is not expected to be a good one for the total memory market and the main culprit is DRAM. Declining shipments of desktop and notebook computers, the biggest users of DRAM, as well as declining tablet PC shipments and slowing growth of smartphone units have created excess inventory and suppliers have been forced to greatly reduce average selling prices in order to move parts. A DRAM ASP decline of 16% coupled with a forecast 3% decline in DRAM unit shipments is expected to result in the DRAM market declining 19% in 2016 (Figure 1), lowest among the 33 IC product categories IC Insights tracks in detail. This steep decline will be a drag on growth for the total memory market (-11%) and for the total IC market (-2%) in 2016.

Figure 1

Figure 1

Big swings in average selling price are not new to the DRAM market. Annual DRAM average selling price increases of 48% and 26% in 2013 and 2014 propelled the DRAM market to more than 30% growth each year. In fact, the DRAM market was the strongest growing IC product segment in each of those years (Figure 2). Then, marketshare grabs and excess inventory started the cycle of steep price cuts in the second half of 2015 and that continued through the first half of 2016.

Figure 2

Figure 2

Figure 3 plots changes in annual DRAM average selling prices starting in 2007.  Looking more like the profile of an alpine mountain range, DRAM ASP growth has taken several dramatic upward and downward turns since 2007, confirming the volatility of this IC market segment. When coupled with strength or weakness in DRAM unit shipments, bit volume demand, and the amount of capacity and capital spending dedicated to DRAM production each year, this market can turn quickly up or down.

Figure 3

Figure 3

On a positive note, DRAM ASPs strengthened in late 2Q16 and are forecast to continue growing through the balance of 2016 and into 2017.  The boost to DRAM ASP is expected to come from demand for enterprise (server) systems, which have been selling well due to the need to process “big data” (e.g., the Cloud and the Internet of Things).  Also, low-voltage DRAM continues to enjoy solid demand for use in mobile platforms, particularly smartphones.  Demand from new smartphone models is expected to help contribute to increasing DRAM ASPs through the end of this year and into 2017.

The upward DRAM ASP trend may be short lived, however, as two China-based companies, Sino King Technology in Hefei, China, and Fujian Jin Hua IC Company, plan to enter the DRAM marketplace beginning in late 2017 or early 2018.  It remains to be seen what devices and what technology the two new entrants will offer but their presence in the market could signal that another round of price declines is around the corner.

Further trends and analysis relating to DRAM and the total memory market through 2020 are covered in the 250 plus-page Mid-Year Update to the 2016 edition of The McClean Report.

SEMI today announced that SEMICON Japan 2016, at Tokyo Big Sight on December 14-16, has increased exhibition and programming to keep pace with high-growth semiconductor segments in Japan. SEMICON Japan, celebrating its 40th anniversary, is the leading electronics event in Japan, with more than 700 exhibitors and 35,000 attendees.

With the world’s largest installed fab capacity of over 4.1 million (200mm equivalent) wafers per month and its diverse product mix, Japan is well-positioned to meet the increasing demands of the new world of electronics – from innovations in mobile technologies to the growing “World of IoT” devices.  SEMICON Japan 2016 connects the players and companies across the electronics manufacturing supply chain by facilitating communications and partnerships. Highlights of the exhibition area include:

  • Themain exhibit zone includes a Front-end Process zone and a Back-end/Materials Process zone.
  • “World of IoT (Internet of Things)”, a “show-within-a-show,” is where semiconductor manufacturing intersects IoT applications including wearable, health care, medical, automotive, and more. The World of IoT this year newly expands its scope to include flexible hybrid electronics (FHE), an essential enabling technology for IoT applications. Exhibiting companies include Japanese flexible and printed electronics companies from key institutes and associations for the industry area.
  • The Sustainable Manufacturing Pavilion, features solutions for the expanding IoT market driving 200mm lines; exhibitors include used and refurbished equipment, cleanroom-related, environmental safety, and more.
  • The Manufacturing Innovation Pavilion showcases innovations for leading-edge lower-cost semiconductor devices; exhibitors include advanced lithography, 2.5D/3D-IC, innovative manufacturing systems, specialty materials, OLED/LED/PE manufacturing equipment and materials.
  • Innovation Village, an interactive exposition showcase arena. Exhibitors are early-stage startups seeking funding, partners, and media exposure in the domain of electronics, materials, IT, tele-communications, bio, med-tech, environment, security or hardware.

For complete information of exhibits and programs, visit www.semiconjapan.org/en.

 

Overall revenue for the power semiconductors market globally dropped slightly in 2015, due primarily to macroeconomic factors and application-specific issues, according to a new report from IHS Markit (Nasdaq: INFO), a world leader in critical information, analytics and solutions.

The global market for power semiconductors fell 2.6 percent to $34 billion in 2015, the report says. Discrete power semiconductor product revenue declined 10.1 percent, while power module revenues decreased by 11.4 percent and power integrated-circuit (IC) revenues increased by 4.5 percent overall.

The report identifies Infineon Technologies as last year’s leading power semiconductor manufacturer, with 12 percent of the market, Texas Instruments with 11 percent and STMicroelectronics with 6 percent.

“While Texas Instruments previously led the market in 2014, the company was overtaken by Infineon Technologies in 2015, following its acquisition of International Rectifier and LS Power Semitech,” said Richard Eden, senior analyst, IHS Markit. “Infineon was the leading global supplier of both discrete power semiconductors and power modules, and the fourth-largest supplier of power management ICs. Infineon has been the leading supplier of discretes for several years, but overtook Mitsubishi Electric to lead the power module market for the first time in 2015, again, due to the International Rectifier and LS Power Semitech acquisitions.”

Figure 1

Figure 1

According to the latest Power Semiconductor Market Share Report from IHS Markit, while Infineon Technologies’ acquisition of International Rectifier was the largest acquisition last year, several other deals also changed the terrain of the power semiconductor market landscape. Key deals in 2015 included the following: MediaTek acquired RichTek; Microchip acquired Micrel; NXP Semiconductors acquired Freescale Semiconductor; NXP Semiconductors also created WeEn Semiconductors, a joint venture with Beijing JianGuang Asset Management Co. Ltd (JAC Capital); CSR Times Electric merged with China CNR Corporation to form CRRC Times Electric; and ROHM Semiconductor acquired Powervation.

“Companies were active in acquisitions for several reasons — especially the low financing cost in multiple regions of the world, which meant that borrowing rates in the United States and European Central bank were nearly zero,” said Jonathan Liao, senior analyst, IHS Markit. “In addition, the acquiring company typically increases its revenues and margins by taking the acquired company’s existing customers and sales without incurring marketing, advertising and other additional costs.”

The Power Semiconductor Market Share Report, part of the Power Semiconductor Intelligence Service from IHS Markit, offers insight into the global market for power semiconductor discretes, modules and integrated circuits. This year’s report includes Power ICs for the first time, as well as discrete power semiconductors and power semiconductor modules. For more information about purchasing IHS Markit information, contact the sales department at [email protected].

The upconversion of photons allows for a more efficient use of light: Two photons are converted into a single photon having higher energy. Researchers at KIT now showed for the first time that the inner interfaces between surface-mounted metal-organic frameworks (SURMOFs) are suited perfectly for this purpose – they turned green light blue. The result, which is now being published in the Advanced Materialsjournal, opens up new opportunities for optoelectronic applications such as solar cells or LEDs. (DOI: 10.1002/adma.201601718)

Photon upconversion: energy transfer between the molecules is based on electron exchange (Dexter electron transfer). Credit: Illustration: Michael Oldenburg

Photon upconversion: energy transfer between the molecules is based on electron exchange (Dexter electron transfer). Credit: Illustration: Michael Oldenburg

Metal-organic frameworks (MOFs) are highly ordered molecular systems that consist of metallic clusters and organic ligands. At the Institute of Functional Interfaces (IFG) of KIT, researchers developed MOFs that grow epitaxially on the surfaces of substrates. These SURMOFs (surface-mounted metal-organic frameworks) can be produced from various materials and be customized using different pore sizes and chemical functionalities so that they are suited for a broad range of applications, e.g. for sensors, catalysts, diaphragms, in medical device technology or as intelligent storage elements.

Another field of application is optoelectronics, i.e. components that are capable of converting light into electrical energy or vice versa. Many of these components work on the basis of semiconductors. “The SURMOFs combine the advantages of organic and anorganic semiconductors,” Professor Christof Wöll, Director of IFG, explains. “They feature chemical diversity and crystallinity, allowing us to create ordered heterostructures.” In many optoelectronic components, a so-called heterojunction – this is an interfacing layer between two different semiconductor materials – controls the energy transfer between the various excited states. Researches of the KIT Institute of Microstructure Technology (IMT) now created a new piggyback SURMOF in which a second SURMOF grew epitaxially, i.e. layer by layer, on a first one. At this heterojunction, it was possible to achieve photon upconversion, transforming two low-energy photons into a single photon with higher energy, by virtually fusing them together. “This process turns green light blue. Blue light has a shorter wavelength and yields more energy. This is very important for photovoltaics applications,” explains Professor Bryce Richards, Director of IMT. The scientists are presenting their work in Advanced Materials, one of the leading journals for materials science.

The photon upconversion process shown by the Karlsruhe researchers is based on the so-called triplet-triplet annihilation. Two molecules are involved: a sensitizer molecule that absorbs photons and creates triplet excited states, and an emitter molecule that takes over the triplet excited states and, by using triplet-triplet annihilation, sends out a photon that yields a higher energy than the photons that were originally absorbed. “The challenge was to create this process as efficiently as possible,” explains Dr. Ian Howard, leader of a junior research group at IMT. “We matched the sensitizer and emitter layers in a way to obtain a low conversion threshold and a higher light efficiency at the same time.”

Since the triplet transfer is based on the exchange of electrons, the photon upconversion process revealed by the researchers includes an electron transfer across the interface between the two SURMOFs. This suggests the assumption that SURMOF-SURMOF heterojunctions are suitable for many optoelectronic applications such as LEDs and solar cells. One of the limitations for the efficiency of today’s solar cells is due to the fact that they can only use photons with a certain minimum energy for electric power generation. By using upconversion, photovoltaic systems could become much more efficient.

Atomic force microscopes make the nanostructure of surfaces visible. Their probes scan the investigation material with finest measurement needles. KIT has now succeeded in adapting these needles to the application. For any measurement task, e.g. for various biological samples, a suitable measurement needle can be produced. For production, 3D laser lithography, i.e. a 3D printer of structures in the nanometer size, is applied.

Atomic force microscopes are used to analyze surfaces down to the atomic level. The standard probes that have been applied for this purpose so far, however, are not suited for every use. Some examination objects require a special shape or a very long probe to scan deep depressions of the material. KIT researchers have now succeeded in producing probes that are optimally adapted to special requirements.

“Biological surfaces, such as the petals of tulips or roses, frequently have very deep structures with high hills,” says Hendrik Hölscher, Head of the Scanning Probe Technologies Group of KIT’s Institute of Microstructure Technology. Commercially available probes typically are 15 micrometers, i.e. 15 thousandths of a millimeter, high, pyramid-shaped, and relatively wide, the physicist points out. Probes with other shapes are offered, but have to be produced manually, which makes them very expensive.

The KIT researchers have now succeeded in producing by means of 3D laser lithography tailored probes of any shape with a radius of 25 nanometers only, corresponding to 25 millionths of a millimeter. This process can be used to design and print in three dimensions any shape desired and has been known in the macroscopic area for some time already. On the nanoscale, this approach is highly complex. To obtain the three-dimensional structures desired, the researchers use the 3D lithography process developed by KIT and commercialized by Nanoscribe, a spinoff of KIT. This method is based on two-photon polymerization: Strongly focused laser pulses are applied to harden light-sensitive materials after the desired structures have been produced. The hardened structures are then separated from the surrounding, non-exposed material. “In this way, the perfect probe can be produced for any sample to be studied,” Hölscher explains.

Use of this process for enhancing atomic force microscopy is reported by the researchers in the Applied Physics Letters journal under the heading “Tailored probes for atomic force microscopy fabricated by two-photon polymerization”. The probes that can be produced in any shape can be placed on conventional, commercially available measurement needles and are hardly subject to wear. They are perfectly suited for studying biological samples, but also technical and optical components in the range od nanometers.