Bringing Perovskite Photovolatics to Consumer Market

Have you ever wondered about the bridge between fundamental scientific research and the consumer market? Or whether or not that solar cell you have been studying for a while would actually make it to the end user? The MRS EN06.09 session presents you with the latest on how to "Bring Perovskites to the Real World for a Smart Future".

One interesting presentation, in this session was the talk by Professor Kylie Catchpole, of Australian National University, presenting on "High Efficiency Perovskite/Silicon Solar Cells and Solar Hydrogen Systems". In her talk, professor Catchpole highlighted the recent increase in installation of photovoltaics in general compared to other electricity production technologies. "Solar and wind energy nowadays are cheaper than coal" emphasized Professor Catchpole, as she explained that the energy production market is mainly driven by cost. Photovoltaics also have the potential to be a low-cost source of hydrogen and other solar fuels. Higher efficiency of solar panels guarantees to lessen the overall cost of solar systems by reducing the number of modules needed. 

The achievement of a highly efficient solar cell is limited by charge recombination processes. Professor Catchpole and her research team used various passivation techniques to enhance the efficiency of their perovskites solar cells. Passivation is the addition of an insulating layer in between the interfaces of the perovskites to prevent charge recombination, as explained by professor Catchpole. In one technique they used an ultrathin (about 5 nm) passivation layer, composed of a mixture of PMMA and PCBM, to achieve high voltage and fill factor. In another technique, a nanostructured electron transport layer was passivated by the PMMA and PCBM mixture. Professor Catchpole’s team was able to achieve an efficiency “above 21% and fill factor of 83% for a 1 cm2 single junction perovskite cell” using this technique. The third passivation technique presented by Professor Catchpole utilizing two-dimensional (2D) perovskites resulted in the remarkable efficiency of 27.7%, for a 4-terminal tandem perovskite/silicon configuration. At the end, Professor Catchpole demonstrated how they used perovskite/silicon tandems in combination with an appropriate catalyst to construct a water splitting system of 17% efficiency. For more on this talk please click here

A simple fundamental understanding of an observation or a phenomena is a goal on its own. It also feels good to see that your work is being used in everyday life. That was my view on Wednesday's virtual MRS Spring Meeting and Exhibit. I will miss writing to you and learning with you as this is my last blog, for now ;) Tot Ziens! 

Very positive take-aways!

Written by Judy Meiksin

During the COVID-19 pandemic, we have been hearing a lot of news of the particular difficulties women in academia have been experiencing. To my surprise, the panelists in the Women in Materials Science & Engineering Keynote Presentation: Perspectives and Take-Aways from the Global Pandemic provided tremendously optimistic views. This began with opening comments by Joanne Etheridge at Monash University in Australia when she said, “I think it’s science that is guiding a path for us to humanity after this whole pandemic.” She emphasized the expertise of scientists that has gotten the world through the pandemic, and that invented, designed, and developed vaccines within 12 months. “What a triumph of human achievement,” she said; “It motivates me actually to be a scientist.”  

Payel Chatterjee at Norwegian University of Science and Technology agreed, “Science can save humanity, nothing else can.” The amount of misinformation and pseudoscience, especially in social media, encouraged Chatterjee to go further into public outreach. “I felt it’s kind of part of my duty as a scientist to make people aware of what’s actually going on in the lab,” she said.

Sandra Young of the US Army DEVCOM remarked, further, on the need for scientists to influence leadership. Before the pandemic, she said, researchers stayed in their laboratories and left it up to leadership to “pick and choose what they’re going to highlight.” What she learned from the pandemic is that scientists need to take responsibility to communicate the impact of their work.

The panelists also discussed, of course, the difficulties of carrying on their work during the pandemic, while also balancing the needs at home and their own health and lifestyle changes. The thing is, everyone found a way. Colleagues stepped in as “family” checking in on one another’s well-being, technology found its way to help keep families connected on the other side of the world. The moderator, Rebecca Anthony of Michigan State University, described the way she deliberately divided up time. Instead of succumbing to the kind of perpetual sort of super work—very pervasive in the US, she said, the pandemic led her to enforce boundaries for different activities.

Then Mmantsae Diale of the University of Pretoria wrapped up the session with even more positives. While technology may be talked about in terms of disrupting the status quo, “this time it is COVID-19 that forces you to use technology to your advantage,” she said. Because of technology, Prof. Diale was able to continue working with her PhD students. “I was able to teach them anytime,” she said, “because they can connect with me through What’s App and ask a question.” Everyone learned well how to use the various communication platforms available, and to also carefully plan what they can accomplish in a fixed period of time due to travel restrictions. Another great platform, Prof. Diale pointed out, is the networking platform at the virtual MRS Meeting. “Don’t miss the opportunity to chat with us one-on-one,” she said.

Meeting the MRS Awardees

Research is a journey of many challenging obstacles followed by some exciting moments. One of these exciting moments is when your hard work, as a scientist, is acknowledged by the scientific community. The MRS reward program aspires to recognize the achievements of pioneers in the field of materials science. The MRS award recipients - lightning talks and panel discussion on Tuesday was a unique opportunity to hear directly from the awardees about their outstanding work. During the session, chaired by Professor Suveen Mathaudhu, five awardees presented and engaged in active discussions about their remarkable contributions to the development of materials research. 

This year's two MRS Postdoctoral Awards were granted to Dr. Yang Liu of the Pennsylvania State University and Dr. Yu Jun Tan of the National University of Singapore. Dr. Liu received this award as a recognition "for the pioneering research in ferroelectric polymers to achieve high piezoelectric responses and outstanding contributions to the understanding of relaxor ferroelectricity in polymers." Dr. Tan explained in her talk that her esteemed work in "developing stretchable, self-healing materials for smart electronics" was inspired by the unique properties of the skin of not only humans but jellyfish! Research in the development of skin-like electronics is also the interest of Professor Zhenan Bao of Stanford University, the recipient of the Mid-Career Researcher Award. Professor Bao was recognized "for pioneering contributions and conceptual developments to organic electronics and skin-inspired electronics." 

The Outstanding Early-Career Investigator Award was granted to Professor Huolin Xin of the University of California, Irvine. This reward is accorded to young scientists working in interdisciplinary materials research. "Although I'm a physicist, I do a lot of work in the chemistry domain," stated Prof. Xin. This statement resonated with me because I also work in a multidisciplinary field of research and often cross the physics/chemistry border. The remarkable work of Professor Xin on the "development of innovative transmission electron microscopy imaging methodologies for advancing energy storage and conversion materials" was the reason behind his recognition. Last but not least Professor Jinawei (John) Miao, of the University of California, Los Angeles, was awarded the Innovation in Materials Characterization Award "for pioneering coherent diffractive imaging for a wide range of material systems and atomic electron tomography for determining atomic positions without assuming crystallinity." You can find the awardees' talks here. I left this session with a lot of information to process but also a strong motivation to work harder on my research.

This was my view of Tuesday's 2021 virtual MRS spring meeting and exhibit. If you enjoyed it, why don't you come back for one more blog post!

BI01.07.05: Modern Sustainable Polymers and Menzypol-Net - How Science Can Bring Us Together

Plastics, as most people refer to common polymers, are responsible for the overflow of the world's landfills and of most of the contamination in our oceans. However, sustainable polymers could be the light at the end of the tunnel. 

The use of polymers is visible in almost every aspect of our modern society, from the plastics we use everyday to the DNA that brought us to existence. Because polymers have a broad range of applications, that allows them to be tuned and applied over the fields of health, engineering, water remediation, and purification. Dr. Natalia Tarazona from the Institute of Active Polymers, states that life cycle development, circular-by-design, and degradation of plastics are three pillars for sustainable polymer development. These would assure that the polymers used in the future would have a reasonable lifespan that reduces the impact on the environment and can be adapted to recycling processes. In order to have an improved recyclability, we would need to implement an enzyme and bacterial-assisted degradation of polymers that can be achieved by certain attainable conditions (such as a change in pH). 

Polyhydroxyalkanoates (PHA) are a class of biobased plastics that are produced by a bacteria-driven biorefinery process that allows them to be biodegradable. However, PHAs recyclability is still an area that needs future research and optimization because they are not easily recyclable. Dr. Tarazona viewed that in the presence of specific enzymes in alkaline environments, biodegradation is possible and can be affected by individual PHA structures.


Menzypol-Net: A Bridge in Polymer Science

Menzypol-Net focuses on forming a partnership between Colombia and Germany to develop the next generation of scientists that use natural resources responsibly and contribute to the microbial diversity in Polymer Science. This network is funded by the German Federal Ministry of Education and Research and the Colombian Ministry of Science Technology and Innovation. Together, they plan to offer joint doctoral programs, workshops, and mobility of researchers that provide an interdisciplinary setting to find solutions for the overaccumulation of plastics in the environment.

If you are interested in PHAs degradation or networking with Menzypol-Net, click here to learn more about Dr. Tarazona’s 2021 MRS Spring Meeting and Exhibit On-Demand presentation.

ST01.12.02: Superhard Incompressible Rhemium Diboride Nanocrystals

Shanlin Hu from the University of California, Los Angeles showed that transition metal borides can behave as incompressible superhard materials. Using rhenium diboride (ReB2) they were able to determine that the hardness increased as its grain size reaches critical values. 

Using a grained mixture of solid sodium chloride, rhenium and boron, the team packed the precursors and then heated them in an Argon flow where the salts were molted and allowed to precipitate. Once the sample is washed, they obtained nanocrystals of ReB2 that ranged between 50nm to 100nm depending on the temperature and washing time.

ReB2 was placed in a high pressure diamond anvil while x-ray beams were passed through the sample to obtain information about the changes in structure due to a pressure of up-to 59 GPa.They plotted the differential strain to pressure relation of ReB2 at bulk, 45 nm and 20 nm sizes to find that, as the nanocrystal structure approached 20 nm, the structures had a greater differential strain than the bulk material. This could possibly be because the grain boundary is competing with the grain interior dislocations.

If you want to harden your knowledge of ultra-incompressible superhard materials, please click here to watch Dr. Hu’s 2021 MRS Spring Meeting and Exhibit presentation on ReB2 nanocrystals.

A New Skin Treatment Strategy

If you are a nonbiologist like me, you might find the news I'm bringing you today quite surprising. Professor Karine Glinel of UC Louvain has presented, at the SM02.03: Anti-Biofilm Materials I session, an interesting approach to treating skin disorders caused by Pathogens. This approach utilizes bacteria existing in the human skin to stimulate the body response against the formation of pathogens. Beneficial bacteria such as Staphylococcus epidermidis can function as "guardian angels" against pathogens, as explained by Prof. Glinel. However, these bacteria have the ability to form biofilms on medical implants and can become virulent. This is why this bacteria itself is often considered a pathogen. The goal of Prof. Glinel's team is to develop a strategy to entrap Staphylococcus epidermidis in a way that allows it to produce agents beneficial for skin health while preventing their uncontrolled growth. To achieve this goal, they tested three methods to functionalize polymer materials.

The first method is based on the formation of a polyelectrolyte shell to encapsulate the bacteria. Although the technique was successful in suppressing the growth of the bacteria, for a period of time, no metabolical activity was observed. The second method is to entrap the bacteria in a network of nanotubes based on polyelectrolyte. In this method, a mat of the nanotubes was fabricated into which the bacteria was trapped. Although the metabolical activity of the bacteria was observed as the mat successfully entrapped it, its suppression of bacteria proliferation only lasted for about 6 h. The final strategy presented by Prof. Glinel was the bacterial encapsulation in a membrane-in-gel patch, which is based on the bacteria entrapment in the pore of a membrane. The tests on this method showed that the bacteria were metabolically active and remained entrapped for 30 h. 

I really enjoyed the fact that, despite my very little knowledge in this field, I was able to follow the main idea and appreciate the findings of Professor Glinel. For more details, you can find this talk here. Also, don't forget to check the Science as Art competition for all the fun and imaginative art that is being made in laboratories. 

That was my Monday's view of the virtual MRS spring meeting and exhibit and if you enjoyed it, stay tuned! 


How Materials Shaped Us

Ainissa Ramirez

Author of The Alchemy of Us

Ainissa Ramirez gave a very compelling talk based on her new book The Alchemy of Us, where she shows how everyday inventions had a hand in shaping language, politics, and even our bodies. Ramirez advocates “storytelling” as a way to successfully discuss materials science with the general public. Through stories, abstract scientific concepts take a meaningful place in their impact on society. For example, materials development that enabled the invention of the telegraph subsequently affected language structure, and artificial lighting has affected human health.

One of the attendees brought up the topic of Li-ion batteries, “When we talk about lithium cobalt oxide for a Li-ion battery, we talk about how good of a cathode it is right now, but that the major source of cobalt in the world has been the Democratic Republic of the Congo and a lot of that comes from child labor.” The attendee further asked Ramirez, “Do you think that by reformatting or reformulating this narrative, we can actually allow for the creation of [a generation of] more ethical scientists?”

“That’s my mission right now,” Ramirez responded. “That’s the reason why I wrote The Alchemy of Us,” she said.

Another ethical question Ramirez brought up—for which she does not have an answer—is about her last chapter called “Think.” Ramirez said that the Internet and silicon devices are altering the way we think. For example, instead of memorizing phone numbers, we pull them from our digital devices. “We now prioritize where the information is instead of what the information is,” she said. The reason this is significant, Ramirez said, is that “if we are creative beings, we need to have the information in our head, simmering in our subconscious, so that we can spit it out in new ways.” Researchers are currently studying the effect of these devices on how we innovate.

See a review of The Alchemy of Us in MRS Bulletin.

Blogger: Judy Meiksin

Organic Photovoltaics for Indoor Applications

Did you know that there are indoor solar cells that can harvest indirect sunlight to power your devices? Did you also know that organic solar cells can have higher efficiencies for indoor applications compared to their counterpart Silicon-based solar cells? This last one was a surprise for me! The talk by Dr. Wing Chung Tsoi of Swansea University, presented in the Organic Photovoltaic I session of the #S21MRS meeting, brings you the interesting news on organic photovoltaic (OPV) cells being "a promising indoor light harvester for self-sustainable electronics".

In his talk, Dr. Tsoi explained that indoor organic solar cells are not only used to power small electronic devices but also for the "internet of things," a technology often used in smart homes and offices. He highlighted that the high efficiency and low cost of OPV, compared to indoor Silicon-based and III-V devices, have brought these devices closer to commercial applications. He also emphasized that indoor OPVs are expected to have significantly higher stability than the OPVs made for outdoor applications, as damaging conditions such as intense light, high heat, and rain are avoided. "We thought that it would be nice to look at the indoor performance again," said Dr. Tsoi as he explained how he, and his colleagues, revisited the use of OPVs for indoor applications amid the discovery of new materials in the field.

At the time, their indoor OPV achieved a record high power conversion efficiency of 28% under 1000 lux fluorescent lamp. This value might be an overestimation, according to Dr. Tsoi, as no standard for indoor efficiency measurement was set yet. Nevertheless, he believes that the efficiency of his OPV would be higher than 20%. At the end of his talk, Dr. Tsoi expressed his hope for a unified standard to compare efficiencies under indoor light of PV made in different laboratories.

It's a nice partially sunny day here in Hasselt and I'm enjoying the sun rays peeking through the clouds to reach my window, as I'm writing to you. It made me wonder if this much light could actually power my laptop ;) What do you think? 

That was my Sunday's view of the Organic Photovoltaic I session and if you enjoyed it, stay tuned!



BI01.02.05: Implementation of Green Engineering Course - Something to Consider

The modern developments in technology have changed and contaminated our world in ways we couldn’t have imagined. Now it is our duty to mitigate the amount of contamination that is present. In that endeavor, Dr. Kaka Ma has developed a course that aims to train future materials developers in the principles of green engineering. 

The course offered in Colorado State University emphasizes the knowledge of a material’s life cycle and how they can influence the environment from the manufacturing process to the disposal management. Another key feature is the use of online or virtual tools like the Granta EduPack to enhance the students' learning of sustainable designs and materials processes. After most of the green background and intuition is developed, the students are then asked to implement the bulk of their attained knowledge to develop project presentations where they can show if a design is an all-around green engineering product.

If today you feel like green is your color, you might want to learn about Dr. Kaka Ma’s 2021 MRS Spring Meeting and Exhibit presentation on an undergraduate green engineering course that promotes active learning by clicking here.

BI01.02: Computer Aid Design to change the future of sustainability.

The presentation given by Dr. Burcu Ozden on the adaptation of computer aid design in materials sustainability showed that in order to continue advancements in Materials Science we need to minimize the waste production caused by not considering enough parameters when developing technologies. 

SOLIDWORKS Sustainability is a platform that provides the user with information about the environmental effects of a product design choice. Properties such as the life-time cycle, financial impact, and air acidification are only some (of many) of the parameters that are readily available. This user-friendly interface serves as a potential initiative to improve the designs of the next generation of materials scientists and materials engineers by giving them the knowledge of the long-term effects of their choice of material for each project. This is extremely useful because when we know how a certain material will affect in the long-run, we can choose the materials that are best suited for the present and the future.

The researcher was aware that a typical curriculum of a materials development program is already loaded with classes that take up almost the entirety of the students' time. Therefore the proposed route is to implement the sustainability analysis of research when there are projects or designs assignments. By evaluating the sustainability of the students' assignments, the designers will be accustomed to keep in mind the long-term consequences of their creations.

If you want to learn more about how SOLIDWORKS Sustainability can have a solid impact on society, make sure to watch Dr. Ozden’s presentation at the 2021 MRS Spring Meeting and Exhibit by clicking here.