Yearly Archives: 2016

Less than a micrometre thin, bendable and giving all the colours that a regular LED display does, it still needs ten times less energy than a Kindle tablet. Researchers at Chalmers University of Technology have developed the basis for a new electronic “paper”. Their results were recently published in the high impact journal Advanced Materials.

Chalmers' e-paper contains gold, silver and PET plastic. The layer that produces the colours is less than a micrometre thin. Credit: Mats Tiborn

Chalmers’ e-paper contains gold, silver and PET plastic. The layer that produces the colours is less than a micrometre thin. Credit: Mats Tiborn

When Chalmers researcher Andreas Dahlin and his PhD student Kunli Xiong were working on placing conductive polymers on nanostructures, they discovered that the combination would be perfectly suited to creating electronic displays as thin as paper. A year later the results were ready for publication. A material that is less than a micrometre thin, flexible and giving all the colours that a standard LED display does.

“The ‘paper’ is similar to the Kindle tablet”, says Andreas Dahlin. “It isn’t lit up like a standard display, but rather reflects the external light which illuminates it. Therefore it works very well where there is bright light, such as out in the sun, in contrast to standard LED displays that work best in darkness. At the same time it needs only a tenth of the energy that a Kindle tablet uses, which itself uses much less energy than a tablet LED display”.

It all depends on the polymers’ ability to control how light is absorbed and reflected. The polymers that cover the whole surface lead the electric signals throughout the full display and create images in high resolution. The material is not yet ready for application, but the basis is there. The team has tested and built a few pixels. These use the same red, green and blue (RGB) colours that together can create all the colours in standard LED displays. The results so far have been positive, what remains now is to build pixels that cover an area as large as a display.

“We are working at a fundamental level but even so, the step to manufacturing a product out of it shouldn’t be too far away. What we need now are engineers”.

One obstacle today is that there is gold and silver in the display, which makes the manufacturing expensive.

“The gold surface is 20 nanometres thick so there is not that much gold in it”, says Andreas Dahlin. “But at present there is a lot of gold wasted in manufacturing it. Either we reduce the waste or we find another way to decrease the manufacturing cost”.

Andreas Dahlin thinks the best application for the displays will be well-lit places such as outside or in public places to display information. This could reduce the energy consumption and at the same time replace signs and information screens that aren’t currently electronic today with more flexible ones.

Peregrine Semiconductor Corp., founder of RF SOI (silicon on insulator), announces that the UltraCMOS PE42723 high linearity RF switch has won an ECN IMPACT Award in the market disruptor category. In addition, the PE42723 switch was named a finalist in the microwaves & RF category, and the PE29100 gallium nitride (GaN) field-effect transistor (FET) driver was recognized as a finalist in the power sources & conditioning devices category. Winners were announced today, Oct. 13, during the awards ceremony.

“For almost three decades, Peregrine has been on the cutting edge of delivering game-changing products to the electronics market,” says Kinana Hussain, Peregrine’s director of marketing. “It is truly an honor to be recognized with an ECN IMPACT Award, especially in the coveted market disruptor category. Products like the PE42723 enable the cable industry to deliver equipment that is fully compliant with today’s stringent communication standards.”

The ECN IMPACT Awards recognize the products and services that have the greatest impact on the electronic components industry. The market disruptor category highlights a product that forever changed the electronic engineering industry or a particular vertical within the industry.

The PE42723 is an RF switch that boasts the highest linearity specifications on the market today. An upgraded version of the successful PE42722, this new RF switch offers enhanced performance in a smaller package. Like its predecessor, the PE42723 exceeds the linearity requirements of the DOCSIS 3.1 cable industry standard and enables a dual upstream/downstream band architecture in the next generation cable customer premises equipment (CPE) devices.

The PE29100 is the world’s fastest GaN FET driver. Built on Peregrine’s UltraCMOS technology, this new GaN driver empowers design engineers to extract the full performance and speed advantages from GaN transistors. Designed to drive the gates of a high-side and a low-side GaN FET in a switching configuration, the PE29100 delivers the industry’s fastest switching speeds, shortest propagation delays and lowest rise and fall times to AC-DC converters, DC-DC converters, class D audio amplifiers and wireless-charging applications.

LED remains the dominant sapphire application in 2016. Overall, rates of usage in smartwatches have been disappointing and have decreased below 2015 levels. In parallel, smartphone display screen opportunities haven’t taken off. Within the highly competitive sapphire industry, players are chasing any opportunity to survive and optimize their cost structure. Prices seem to have reached bottom and stabilized after a rough ride over the last 12 months. After a dip in the second half of 2015, LED substrate demand has been growing strongly through 2016 and is now at record high levels, even triggering a limited shortage of high-quality 4″ materials and wafers. According to Yole Développement (Yole), the worldwide quarterly sapphire wafer consumption for LEDs has reached 28.5 million of TIE (Q3, 2016).

In its new report, Sapphire Market 2016: Substrates & Consumer Electronics Applications (September 2016, Yole Développement), Yole, the More than Moore market research and strategy consulting company, has analyzed the sapphire industry’s latest technology and market trends. Yole used a dedicated methodology based on both top-to-bottom and bottom-up approaches that included interviews across the entire value chain and a strong knowledge of the industry to review the status and prospects of sapphire technologies for LEDs, camera lenses, and fingerprint reader covers, as well as smartwatch and smartphone displays.

Once again this year, the consulting company collaborated with CIOE to present a powerful program at the International Forum on Sapphire Market & Technologies, 2nd edition (Shenzhen, China – Sept. 6 & 7, 2016 – Agenda). Sapphire industry leaders attended the conference and discussed the latest innovations and market challenges.

What is the status of the sapphire industry? After the 2014 crash, the episode with Apple, and GTAT’s bankruptcy, are there still some survivors? What are their today’s strategies? Beyond existing applications, could we expect emerging applications? Yole’s analysts offer you an overview of the current sapphire industry and announce 2017 trends.

The LED sector still has the highest demand for sapphire. However, Yole’s analysts confirm: the expected volumes cannot sustain the one hundred or so sapphire producers currently competing in the industry. As a consequence, some sapphire companies are leaving the most commoditized markets and shifting their development strategies toward niche markets with higher added-value such as medical, industrial, and military applications. Other business opportunities could materialize, including microLED arrays and other consumer applications. Meanwhile, lower quality production is being dumped on a large grey market serving a multitude of applications including optical, mechanical, industrial, watches, etc.

In Shenzhen, China, at the beginning of September, more than 100 executives gathered and discussed the sapphire industry’s status. With an impressive program including 18 presentations, multiple debates and networking sessions, the sapphire industry’s future was defined and analyzed by sapphire leaders. Yole and its partner CIOE collected good feedback from attendees and are already thinking about a 2017 session.

During this Forum, many relevant and exciting presentations took place, mainly focused on optimizing costs and identifying new markets. Dr. Eric Virey from Yole highlighted the sapphire industry, its latest technical and market trends with a special focus on emerging applications. (See Dr. Eric Virey presentation – 2nd Int. Forum on Sapphire Market & Technologies).

In the same session, leading sapphire manufacturers Monocrystal and Aurora Sapphire also reviewed their insights as key sapphire market players:

•  Mikhail Berest, VP of Sales at Monocrystal, detailed Monocrystal strategies: “The market is challenging not only for sapphire producers, but also for our customers. Our major focus is to strongly support our customers during this market storm by providing them with the highest quality product at a competitive price. We make this possible because Monocrystal’s sapphire is industry-leading due to its low internal stress and low etch pit density. This translates into longer LED lifetime and narrow wavelength distribution on our customers’ side…” (Full discussion on i-micronews, compound semi. news)

•  Xinhong Yang, VP & Technology Director, Aurora Sapphire, presented the latest technology innovations. He also focused his presentation on the future of the sapphire industry.

•  On the application side, Unionlight’s CTO, Huang XiaoWei, discussed military applications of sapphire in the last sapphire Forum session.

Reducing costs and improving quality were major topics discussed at the Forum. Fujian Jing’an Optoelectronics highlighted the importance of subsurface damages. Edouard Brunet, R&D Manager Grains & Powders Asia, Saint-Gobain High Performance Materials, introduced a 1-step polishing process with significant potential for cost reductions. Bernard Jones, VP of Technology & Product Development at Fametec, showed an innovative growth technology for large diameter LED wafers, and Ivan Orlov, Scientific Visual’s CEO, triggered extensive discussions after his presentation on automated ingot inspection and mapping equipment and standardization proposals.

“Once again, the International Forum on Sapphire Market & technologies brought together many players”,comments Jean-Christophe Eloy, President & CEO, Yole Développement. “It showed that in the difficult market environment we’ve experienced since late 2015, the industry needs to gather and exchange information in order to optimize ownership costs and enable new applications.”
Yole & CIOE’s sapphire Forum provided a great platform to stimulate discussion and new ideas with extensive networking opportunities for people and companies to find new partners for the next stage.

“The International Forum on Sapphire Market and Technologies is the key industry event for the main sapphire makers,” asserts Oleg Kachalov, CEO of Monocrystal.“For Monocrystal, it is a chance to meet long-term partners and experts and reach our customers with our new developments, which will allow them to strengthen their position in the LED market.”

“I was impressed by the quality of content presented at Yole & CIOE’s sapphire Forum 2016, which provided not only trend analysis but also deep insights”, says Margaret Connolly, VP of UBM Asia. “The event was well attended by the industry’s key decision makers. The collaboration between CIOE and Yole has been quite successful as the teams are committed to the common objective which is to support long term technology development and innovations. I look forward to attending the 2017 edition in Shenzhen.” UBM owns 100% of eMedia Asia, the majority owner of the annual CIOE.

What can we expect for 2017 and the years after?

Massive adoption of sapphire in display screens now seems unlikely. Many companies have partially or completely exited the industry over the last 12 months. Independent crystal growers in Korea such as DK-Aztek, OCI, and Unid LED have all stopped their sapphire activities. Historical players in Taiwan such as Tera-Xtal, Crystal Applied Technology or Procrystal appear to be on the verge of bankruptcy and U.S. leader Rubicon recently shut down its facility in Malaysia and exited the LED wafer market to refocus on the optical, industrial, and defense markets. But key players are still investing.

So, is there still hope for 2017? To answer that question, both Yole and CIOE are already working on a new sapphire Forum in 2017 in Shenzhen, China. Agenda & registration will be available soon. Stay tuned!

SEMICON Europa 2016, opening in less than two weeks in Grenoble, will explore the issues facing Europe’s semiconductor and electronics industries, including processes, materials, equipment and supply chain. SEMICON Europa (October 25-27) is a leading exhibition and conference dedicated to the future of electronics in Europe.

As semiconductor manufacturers target new high-growth European strength areas, SEMICON Europa connects the European ecosystem and the global manufacturing supply chain by offering new business opportunities like advanced packaging, MEMS, imaging, power electronics, flexible hybrid electronics, automotive, smart manufacturing, medtech and addressing the demands of the IoT.

Executive keynotes include:

  • GLOBALFOUNDRIES Dresden: “FDX and FinFET: Differentiated Technologies for Diverging Markets” presented by Dr. Rutger Wijburg, senior VP and GM
  • Intel Israel: “How Technology and Equipment March Forward Hand-in-Hand” presented by Maxine Fassberg, CEO
  • CEA-Leti: “European Chance in Industry and Technologies” presented by Marie-Noëlle Semeria, CEO

In addition, companies such as Infineon, STMicroelectronics, ABB, ASML, Applied Materials, SOITEC, imec and Fraunhofer, and hundreds more, will present the latest trends, technologies, processes and techniques in electronic applications, design and manufacturing.

This year for the first time, Iot Planet will co-locate with SEMICON Europa. The combined shows are expected to attract 7,000 professionals and more than 600 visiting companies, giving attendees the opportunity to conduct business up and down the supply chain.  New programs, like the B2B Matchmaking Event 2016, offer visitors and exhibitors an opportunity to prearrange appointments.

SEMICON Europa is co-located with 2016FLEX Europe which covers the field of large-scale electronics, with emphasis on printed, flexible and organic electronics and its convergence with conventional semiconductor manufacturing.

Register now and take advantage of our early pricing for conferences, forums, and select sessions. To register for SEMICON Europa 2016, please visit: www.semiconeuropa.org

Samsung Electronics Co., Ltd. today announced a new line-up of chip scale package (CSP) LED modules for spotlights and downlights that features color tunability and increased design compatibility.

LED_Image

“Our new CSP LED modules provide an optimal solution for lighting manufacturers who seek highly compatible and reliable LED components,” said Jacob Tarn, Executive Vice President, LED Business Team at Samsung Electronics. “Samsung will continue to strengthen its CSP technology leadership and spearhead new innovations in LED component technology to bring greater value to our customers.”

The new LED modules are Samsung’s first to incorporate CSP technology, which bring a wide range of lighting benefits such as significantly reducing the size of a conventional LED package. The combination of advanced flip chip and phosphor coating technology eliminates metal wires and plastic molds to enable more compact designs when manufacturing LED modules and fixtures.

In addition to their size advantage, Samsung’s new CSP LED modules deliver further characteristics that furnish seamless tunable color. A color-tunable LED module requires twice the number of LED packages in cool and warm temperature, which work in combination on the same board to create a range of tunable colors. In contrast to conventional plastic-molded LED packages that inevitably increase the size of the modules, Samsung’s ultra-compact chip scale LED packages allow the module size to remain unchanged.

Samsung’s new CSP LED modules are available in two form factors (19x19mm or 28x28mm) and are designed following Zhaga specifications, making them highly convenient in assembling. The modules also provide high-quality lighting in diverse beam angle options – spot, medium, wide – for improved compatibility with the optical solutions of Samsung’s partners. The new modules are based on CSP LED packages that have successfully completed 9,000 hours of LM-80 testing, a level of proven performance that reduces the time to market for lighting manufacturers.

Samsung is now sampling six models of the new CSP LED module in CRI 80 and 90 with varying lumen output, size and CCT specifications. The full line-up includes:

 Power

Form Factor 

Model

 Consumption

Lumen

(mm)

CCT
CO10 9.4 1050 lm 19×19 2700/3000/3500/4000K
CO20 18.3 2060 lm 19×19
CO30 27.4 3090 lm 28×28
CO40 36.5 4120 lm 28×28
TO10 9.2-9.8 1060 / 1150 lm 28×28

Color tunable between
2700K~5000K
TO20 17.7-18.4 1970 / 2190 lm 28×28

* Based on CRI 80

Semiconductor Manufacturing International Corporation (“SMIC”; NYSE:  SMI; SEHK: 981), the largest and most advanced foundry in Mainland China, today held the groundbreaking ceremony of a new 12-inch wafer fab in Shanghai to meet SMIC Shanghai’s increasing production and development needs.

China’s Ministry of Industry and Information Technology (MIIT) and the Shanghai Government have placed a high value on and provided strong support for the new project. Guests and leaders from the IC industry and investment funds attended the ceremony. The Chairman of SMIC, Dr. Zixue Zhou, and the CEO and Executive Director of SMIC, Dr. Tzu-Yin Chiu, together laid the foundation stone for the new project.

SMIC has 8-inch and 12-inch wafer fabs in Beijing, Shanghai, Shenzhen, Tianjin and Italy, and the company’s revenue has continued to hit record highs recently. SMIC booked record revenue of US $1.3245 billion in the first half of 2016 (a year-on-year increase of 25.4%). SMIC has achieved 17 consecutive quarters of profit and is close to full production capacity. Revenue is expected to maintain rapid growth of 20% annually over the next three to four years. SMIC will manage production capacity and arrange facility expansions based on customer and market demand.

The Chairman of SMIC, Dr. Zixue Zhou, said: “The start of our new 12-inch wafer fab in SMIC Shanghai will not only help to meet our growing customer demand for advanced production, but also further strengthen and expand SMIC itself.”

Nature has inspired generations of people, offering a plethora of different materials for innovations. One such material is the molecule of the heritage, or DNA, thanks to its unique self-assembling properties. Researchers at the Nanoscience Center (NSC) of the University of Jyväskylä and BioMediTech (BMT) of the University of Tampere have now demonstrated a method to fabricate electronic devices by using DNA. The DNA itself has no part in the electrical function, but acts as a scaffold for forming a linear, pearl-necklace-like nanostructure consisting of three gold nanoparticles. The research was funded by the Academy of Finland.

The DNA itself has no part in the electrical function, but acts as a scaffold for forming a linear, pearl-necklace-like nanostructure consisting of three gold nanoparticles. Credit: the University of Jyväskylä

The DNA itself has no part in the electrical function, but acts as a scaffold for forming a linear, pearl-necklace-like nanostructure consisting of three gold nanoparticles. Credit: The University of Jyväskylä

The nature of electrical conduction in nanoscale materials can differ vastly from regular, macroscale metallic structures, which have countless free electrons forming the current, thus making any effect by a single electron negligible. However, even the addition of a single electron into a nanoscale piece of metal can increase its energy enough to prevent conduction. This kind of addition of electrons usually happens via a quantum-mechanical effect called tunnelling, where electrons tunnel through an energy barrier. In this study, the electrons tunnelled from the electrode connected to a voltage source, to the first nanoparticle and onwards to the next particle and so on, through the gaps between them.

“Such single-electron devices have been fabricated within the scale of tens of nanometres by using conventional micro- and nanofabrication methods for more than two decades,” says Senior Lecturer Jussi Toppari from the NSC. Toppari has studied these structures already in his PhD work.

“The weakness of these structures has been the cryogenic temperatures needed for them to work. Usually, the operation temperature of these devices scales up as the size of the components decreases. Our ultimate aim is to have the devices working at room temperature, which is hardly possible for conventional nanofabrication methods – so new venues need to be found.”

Modern nanotechnology provides tools to fabricate metallic nanoparticles with the size of only a few nanometres. Single-electron devices fabricated from these metallic nanoparticles could function all the way up to room temperature. The NSC has long experience of fabricating such nanoparticles.

“After fabrication, the nanoparticles float in an aqueous solution and need to be organised into the desired form and connected to the auxiliary circuitry,” explains researcher Kosti Tapio. “DNA-based self-assembly together with its ability to be linked with nanoparticles offer a very suitable toolkit for this purpose.”

Gold nanoparticles are attached directly within the aqueous solution onto a DNA structure designed and previously tested by the involved groups. The whole process is based on DNA self-assembly, and yields countless of structures within a single patch. Ready structures are further trapped for measurements by electric fields.

“The superior self-assembly properties of the DNA, together with its mature fabrication and modification techniques, offer a vast variety of possibilities,” says Associate Professor Vesa Hytönen.

Electrical measurements carried out in this study demonstrated for the first time that these scalable fabrication methods based on DNA self-assembly can be efficiently utilised to fabricate single-electron devices that work at room temperature.

The research builds on a long-term multidisciplinary collaboration between the research groups involved. In addition to the above persons, Dr Jenni Leppiniemi (BMT), Boxuan Shen (NSC), and Dr Wolfgang Fritzsche (IPHT, Jena, Germany) contributed to the research. The study was published on 13 October 2016 in Nano Letters. Collaborative travel funding was obtained from DAAD in Germany.

SEMI recently completed its annual silicon shipment forecast for the semiconductor industry. This forecast provides an outlook for the demand in silicon units for the period 2016–2018. The SEMI forecast shows polished and epitaxial silicon shipments totaling 10,444 million square inches in 2016; 10,642 million square inches in 2017; and 10,897 million square inches in 2018 (refer to table below). Total wafer shipments this year are expected to exceed the market high set in 2015 and are forecast to continue shipping at record levels in 2017 and 2018.

“Silicon shipment volumes have been gaining strength in recent months, after a soft start at the beginning of the year,” said Denny McGuirk, president and CEO of SEMI. “This positive momentum is expected to continue and result in modest annual growth for the segment this year, 2017 and into 2018.”

2016 Silicon Shipment Forecast

Total Electronic Grade Silicon Slices* – Does not Include Non-Polished Wafers

(Millions of Square Inches, MSI)

Actual

Forecast

2014

2015

2016

2017

2018
MSI

9,826

10,269

10,444

10,642

10,897
Annual Growth

11%

5%

2%

2%

2%

Source: SEMI, October 2016

* Shipments are for semiconductor applications only and do not include solar applications

Silicon wafers are the fundamental building material for semiconductors, which in turn, are vital components of virtually all electronics goods, including computers, telecommunications products, and consumer electronics. The highly engineered thin round disks are produced in various diameters (from one inch to 12 inches) and serve as the substrate material on which most semiconductor devices or “chips” are fabricated.

All data cited in this release is inclusive of polished silicon wafers, including virgin test wafers and epitaxial silicon wafers shipped by the wafer manufacturers to the end-users. Data do not include non-polished or reclaimed wafers.

SEMI today announced the retirement of Dennis (Denny) McGuirk, SEMI’s president and CEO. McGuirk has served on the board of directors and has led SEMI, the global industry association representing more than 2,000 companies in the electronics manufacturing supply chain, since November 2011. McGuirk will continue to lead SEMI in his current capacity until a successor is appointed.

While at SEMI, McGuirk has had responsibility for driving member satisfaction through SEMI’s global operations – anchored by eight international SEMICON expositions – and SEMI products and services including: Standards, market intelligence, business and technical programs, and industry advocacy. Over the past five years, the electronics manufacturing supply chain has undergone major changes as digital mobility, industry consolidation, and regional investment shifts have reshaped the industry. During this period, McGuirk provided stewardship and new direction to SEMI’s operations, expositions, communities, and partnerships.

“Upon joining, Denny realigned SEMI’s operations to be financially sustainable,” said Y.H. Lee, chairman of SEMI’s board of directors. “Denny has been a consistent and hospitable SEMI ambassador at our SEMICON tradeshows around the globe. We thank Denny for his service and many contributions and wish him well in his retirement.”

“After five years at SEMI, the time is right for me to retire. I am grateful to have worked with SEMI’s exceptional members and outstanding employees – the semiconductor industry is one of the most innovative and fast-paced industries in the world, where only the truly excellent thrive. It’s been great to lead a truly global association such as SEMI with achievements at both regional and international levels. I’m committed to ensure a smooth transition to my successor for the continued success of SEMI.”

A leading executive search firm has been engaged to assist in identifying and evaluating candidates, who can assume the responsibility to continue to focus on the growth and prosperity of SEMI members and drive SEMI’s 2020 vision.

A team of Shanghai Jiao Tong University researchers has used the shape of cicada wings as a template to create antireflective structures fabricated with one of the most intriguing semiconductor materials, titanium dioxide (TiO2). The antireflective structures they produced are capable of suppressing visible light — 450 to 750 nanometers — at different angles of incidence.

I. Photograph and scanning electron microscope characterizations of a black cicada wing (Cryptympana atrata Fabricius). II. Synthesis process of biomorphic TiO2 with ordered nano-nipple array structures. III. Counter map angle-dependent antireflection of biomorphic TiO2 and non-templated TiO2, respectively. Credit: Shanghai Jiao Tong University

I. Photograph and scanning electron microscope characterizations of a black cicada wing (Cryptympana atrata Fabricius). II. Synthesis process of biomorphic TiO2 with ordered nano-nipple array structures. III. Counter map angle-dependent antireflection of biomorphic TiO2 and non-templated TiO2, respectively. Credit: Shanghai Jiao Tong University

Why cicada wings? The surfaces of the insect’s wings are composed of highly ordered, tiny vertical “nano-nipple” arrays, according to the researchers. As they report this week in Applied Physics Letters, from AIP Publishing, the resulting biomorphic TiO2 surface they created with antireflective structures shows a significant decrease in reflectivity.

“This can be attributed to an optimally graded refractive index profile between air and the TiO2 via antireflective structures on the surface,” explained Wang Zhang, associate professor at State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University in China.

Small spaces between the ordered nano-antireflective structures “can be thought of as a light-transfer path that let incident light rays into the interior surface of the biomorphic TiO2 — allowing the incident light rays to completely enter the structure,” Zhang continued. “The multiple reflective and scattering effects of the antireflective structures prevented the incident light from returning to the outside atmosphere.”

Significantly, the team’s work relies on “a simple and low-cost sol-gel (wet chemical) method to fabricate biomorphic TiO2 with precise subwavelength antireflective surfaces,” Zhang pointed out. “The TiO2 was a purely anatase phase (a mineral form of TiO2), which has unique antireflective surfaces. This led to an optimally graded refractive index and, ultimately, to angle-dependent antireflective properties within the visible light range.”

In terms of applications, the team’s biomorphic TiO2 antireflective structures “show great potential for photovoltaic devices such as solar cells,” Zhang said. “We expect our work to inspire and motivate engineers to develop antireflective surfaces with unique structures for various practical applications.”

Even after high calcination at 500 C, the antireflective structures retain their morphology and high-performance antireflection properties. These qualities should enable the coatings to withstand harsh environments and make them suitable for long-term applications.

In the future, the team plans “to reduce the optical losses in solar cells by using materials with a higher refractive index such as tantalum pentoxide or any other semiconductor materials,” Zhang said.