Sorry, this entry is only available in Brazilian Portuguese.
From September 5 to 7, 2020, a few dozen students and young researchers, together with some professors, dedicated the afternoons of the holiday of Brazil’s Independence Day to participate, online, in the 1st National Meeting of the B-MRS University Chapters (I ENUC).
The event brought together members of University Chapters (UCs) and people interested in meeting them. The program was built around two axes: the UCs’ presentations about their teams, institutions, actions carried out and future projects, and the invited lectures on topics of interest to the UCs.
ENUC emerged from the desire of the UC from the Federal University of Pernambuco (UFPE) to interact with members of other B-MRS UCs. In this first edition, the event was fully organized and carried out by the members of UC-UFPE.
UCs in action: learn by doing
In his lecture, Professor Newton Barbosa (UFPA), national coordinator of the UCs program reflected that in the scientific career being competent in the chosen area of knowledge is essential, but it is not enough, especially at the present moment in the history of science and technology, in which problem solving requires the interaction between people and areas. Skills such as communication, flexibility, and proactive leadership, he said, are also necessary for the researcher. The scientist explained that “the idea of the UCs program is precisely to help develop these skills, using the learn-by-doing method, with students carrying out team projects.”
“Research alone will not fill our CV,” added Karolyne Santos da Silva, president of UC UFPE. “We will also need to organize events, occupy administrative positions, publicize our work in society, among other things,” added the doctoral student, who was the event coordinator.
A wide range of projects carried out by the chapters were presented throughout the event, which covered from the creation of the unit’s logo and internal statute, to lectures and interviews for laypeople, workshops to motivate girls to work in science and technology, and seminars for researchers. Support for social action campaigns is also part of the activities carried out by the UCs, always with the dual objective of learning-by-doing and generating a positive impact on the environment.
The social impact of research
In one of the invited lectures, Professor Roberto Faria (IFSC-USP), who was president of B-MRS between 2012 and 2015, spoke briefly about the history of the UCs program. “I wanted the students’ greater participation in B-MRS, as they are the country’s greatest wealth for the future,” said the former president of B-MRS. Faria said that it all started in 2013, during his first term as president of B-MRS. At a scientific event in San Francisco (USA), Professor Faria spoke with the coordinator of the Materials Research Society (MRS) university chapters program, who was none other than Mildred Dresselhaus, a scientist internationally renowned for her work with carbon nanomaterials, who passed away in 2017. One year after this conversation, the B-MRS UCs Program was operating with 4 active units. Before ending his speech, Faria invited the members of the UCs to reflect on the relationship of materials research with the development of Brazil and the problems of Brazilians, to find solutions to the contradiction between the country’s natural wealth and the low quality of life of a large part of its population.
The social impact of the research was also addressed in a lecture by professor Eduardo Martinelli (UFRN), scientific director of B-MRS and coordinator of the Materials area at CAPES, the federal government agency, responsible for quality in undergraduate and postgraduate institutions in Brazil. Martinelli shared the work that CAPES has been doing to create metrics that objectively reveal the impacts generated by postgraduate courses on people’s quality of life. “Society invests in us, researchers, and we need to answer how we benefit society.” This concern also appeared in the presentations of the UCs, in actions aimed at showing laypeople the presence and importance of science in everyday life.
Diversity, representativeness and multidisciplinarity
With units in all Brazilian regions, members of different ethnic groups and a good proportion of women on the boards, the UCs program is very close to the ideal of diversity and representativeness. Thus, these two concepts were intensely debated throughout the event, starting with the opening lecture by professor Mônica Cotta (UNICAMP), president of B-MRS (the first woman to occupy this position in the Society). “It is not by chance that today we have two women at the opening of the meeting, the president of the Society and the event coordinator,” stated Professor Petrus Santa Cruz (UFPE), tutor of the UC -UFPE.
In the lecture, Professor Cotta also spoke about the role of scientific societies and, in particular, about the past, present and future of B-MRS. “For me, the future is related to university chapters, because it is their members who are able to better communicate with new generations,” she said. The president showed that the history of B-MRS is linked to the highly multidisciplinary nature of materials research, which requires merging the knowledge of physicists, chemists, biologists, engineers, medical doctors and other professionals.
Belonging to a generation more accustomed to a multidisciplinary approach, the members of the chapters naturally included the subject in their presentations, which showed the efforts by students from different areas of knowledge.
The most evident result of the event was enabling each UC to get to know the other units. In the evaluation of the organizing team, the meeting allowed to reflect on the effectiveness of all projects, and the possibilities for adapting each action to the different realities of the country. “I highlight the exchange of experiences and ideas between the various UCs, which reflect the cultural plurality of Brazilian society and the various areas that compose the materials community,” says Professor Mônica Cotta, president of B-MRS, who participated in the entire event.
The I ENUC was also a generator of joint projects. “Without a shadow of a doubt, ENUC promoted in an unprecedented way the integration between the various UCs in our program, which can already be seen in practical terms with the organization of a cycle of webinars, which was a result of the event,” said Professor Newton Barbosa, national coordinator of the UCs Program, who also followed the event in its entirety.
In addition, the event provided a broader contact between the members of the program with the B-MRS board and with other people who work or have worked in the Society. “It was especially motivating to be able to observe the maturity, commitment and involvement of these students with the values we share at B-MRS and in the academic area in general, such as respect for science and scientific method, ethical values, diversity and representativeness in all aspects,” expressed the president of the Society.
Another important result of the I ENUC, according to Professor Barbosa, was to have perfected the idea of what it means to be a member of a B-MRS UC. “Being part of a chapter means, at a very young scientific age, participating in the discussions of macro problems of Materials Science and Engineering. Being able to think and propose, in a professional and respectful way, solutions to these problems. Go beyond the laboratory bench and become a professional with multiple skills,” summarized the program coordinator.
Communication and sponsorships
The event also featured a lecture by Verónica Savignano, responsible for Communications at B-MRS. The scientific journalist presented all the communication channels of B-MRS, their audiences and contents, in order to open interaction possibilities with the UCs. Speaking to a generation that is much more accustomed to dissemination (via social networks) than the previous generation, the journalist strived to generate a reflection on the criteria and guidelines (ethical, aesthetic and technical) that should guide the work of communication. During the questions, the discussion revolved around the concepts of disinformation, infodemics, pseudoscience and fake news.
Finally, in another invited lecture, Rosely Maier Queiroz, former financial director of UC-UFPE, shared a step-by-step on how to get sponsorship and manage the budget of UC projects, with specific tips for this time of pandemic and economic crisis.
Independence, Technology and Fight
“I think the date of this event is symbolic, as the independence of a country depends on technological independence,” said Professor Petrus Santa Cruz, when opening the meeting. “This year there is no Independence parade because of the pandemic, but there is a fight alert, the fight for education, for science, for the reduction of social inequalities,” said Karolyne, ending the event.
The event was recorded and is available on the UC-UFPE YouTube channel.
Thanks to the contributions of research groups from different countries, perovskite-based solar cells have quickly become competitive in terms of energy conversion efficiency – the percentage of solar energy that is converted into electrical energy – reaching values above 25%. Unfortunately, the good efficiency achieved for these solar cells does not remain throughout their use, mainly because of the instability of their active layer. Composed of materials from the perovskite family, this layer of the sandwich-like solar cell is responsible for absorbing light. Due to moisture, as well as light itself, perovskite degrades and threatens the life cycle of a solar cell.
The problem has been the focus of many researchers in the area, among them, those from the Laboratory of Nanotechnology and Solar Energy (LNES) at Unicamp (Brazil), led by Professor Ana Flávia Nogueira. In recently reported research in the Journal of Materials Chemistry C (impact factor 7.059), LNES members were able to produce more stable perovskite films which allowed manufacturing solar cells with lower efficiency losses over time.
The strategy adopted was to add to the perovskite a compound that gives it stability without affecting its crystalline structure, from which important properties emerge for solar cell performance. The chosen additive, a copolymer (polymer formed by two different monomers), was added in different concentrations to a solution of lead iodide and methylammonium iodide, which, when crystallized, formed a modified and more stable perovskite film.
The researchers used the spin coating technique to prepare filmes of pure perovskite and “additivated” perovskite. In a material degradation test, the authors exposed the samples to ambient light and humidity for nine days and observed their degradation, which was visible to the naked eye by the yellowing of the films, whose original color is almost black. In the samples with additive, the degradation was delayed by a few days when compared to the pure perovskite samples.
Another test carried out by the team showed the films’ ability to regenerate after an initial degradation caused by exposure to a humidifier. The samples with the additive not only degraded less, but also spontaneously regenerated, almost entirely, thirty seconds after removing the moisture source – a phenomenon known as healing – as can be seen in this video.
“This work demonstrated that incorporating a copolymer based on poly(ethylene oxide) to the perovskite layer can delay and, in some cases, even reverse the degradation process of the film with relation to moisture and lighting,” summarizes Jeann Carlos da Silva, co-author of the article.
To study in detail the structure and composition of the films, the authors used a series of characterization techniques, including an X-ray diffraction technique (in situ GWAXS), available at the Brazilian National Synchrotron Light Laboratory (LNLS), which allowed to monitor the manufacturing process of the films. Based on the set of characterization results, the authors were able to explain the mechanism that generates the protective effect in perovskite films with additives. According to them, the effect occurs mainly due to the interaction performed by the copolymer, through hydrogen bonds, with the methylammonium cation of the perovskite. In films without the additive, light and moisture cause part of the methylammonium to shift into the gas state and then leave the perovskite structure, generating the degradation, which is partially irreversible. In the films with the additive, the copolymer retains the methylammonium, which generates films that are more stable and have greater regenerative capacity.
“This study also allowed to investigate the crystallization dynamics of the perovskite containing the copolymer, as well as to understand the formation mechanisms of perovskite/copolymer in humidity and lighting conditions,” highlights Francineide Lopes de Araújo, co-author of the article. “In addition, through characterization techniques such as in situ X-ray diffraction, the study explores an important area in order to understand the material, offering an important contribution to the scientific community and opening new investigation perspectives for the application of polymers in the process of forming and manufacturing perovskite solar cells,” she adds.
Finally, the scientific team manufactured solar cells using perovskite films with and without additives as active layer, and compared their energy conversion efficiency. Initially, the presence of the copolymer decreased the efficiency of the devices, since, as it is an insulating material, it impairs the transfer of electrical charges. However, in the stability tests, when the devices were exposed to humidity and light for twenty days, the perovskite cells with additives performed better.
In numbers: while pure perovskite solar cells started at 17% efficiency and maintained 47% of that value at the end of the test, perovskite devices containing 1.5 mg mL-1% copolymer had an initial efficiency of around 15 %, but retained 68% of efficiency after the 20 days of testing.
“Unfortunately, the problem of stability of perovskite solar cells could not be definitively solved through this research, however, an important way to protect the material was explored, mainly against aggressive exposure to moisture and light, which in the future can be combined with other protection mechanisms,” summarizes Jeann Carlos da Silva. “The research also reinforces the feasibility of incorporating extrinsic compounds to perovskite as protective agents,” he adds.
This study began at LNES in 2016, in the master’s research of Jeann Carlos da Silva, shortly after the development, in that same laboratory, of the first perovskite solar cell prototype in Brazil. The research was completed with the collaboration of the postdoctoral fellow Francineide Lopes de Araújo and other members and former members of the group, always under the guidance of Professor Ana Flávia.
The study was funded by Brazilian agencies FAPESP, CNPq and CAPES, and is the subject of the project “Perovskite Solar Cells for Artificial Photosynthesis” of the Center for Innovation on New Energies (CINE) with support from Shell and Fapesp.
[Text by Professor Petrus Santa Cruz (DQF/UFPE), B-MRS member.]
Some researchers make a difference in contributing for consolidating important areas of Science in Brazil. In the case of Professor Larry Clark Thompson, of the University of Minnesota-Duluth, he will always be remembered not only for his significance in the area of coordination compounds in the country, but also for his generosity. During the workshop “Larry Thompson and Brazil” held to celebrate 40 years of international cooperation in 2009, the beginning of his contributions to Brazilian science in 1970 was remembered, when he received professors Gilberto Sá (DQF/UFPE) and Oswaldo Serra (USP/Ribeirão Preto) in his group in the USA, resulting in collaborations that extended throughout his academic life.
Over the past 50 years, several episodes have been marked by his generosity.
In 2002 Professor Thompson participated in a thesis panel at DQF/UFPE on pioneering works in exploring the degradation of lanthanide complexes, which resulted in an innovative dosimeter device for measuring UV radiation, but before participating in the panel, Thompson hosted the doctoral student at his residence in Minnesota -Duluth, so that she could show him in his laboratory that the complexes actually degraded under the action of UV radiation, giving rise to a new line of research on devices for the prevention of skin cancer, currently explored for individual monitoring of vitamin D in a project of the Sibratec Nano program. Several other applications use as an active part the luminescent materials derived from his work.
Thompson was in Brazil for the last time in 2017, but unfortunately this year circumstances prevented the workshop “Larry Thompson and Brazil” of the 50 years of collaborations. He passed away at the age of 85 on August 15th, leaving behind many memories.
The Brazilian Materials Research Society (B-MRS/ SBPMat) and the International Union of Materials Research Societies (IUMRS) invite the scientific community to submit symposium proposals for the joint event on materials research that will take place from August 29 to September 2, 2021.
Symposium proposals can be submitted until November 2, for the event that will bring together the XIX B-MRS Meeting (B-MRS annual event) and the IUMRS – ICEM (seventeenth edition of the international conference on electronic materials organized every two years by IUMRS).
The event, initially scheduled to take place in 2020, was postponed due to the pandemic, and will be held from August 29 to September 2, 2021. The place remains the same: the Rafain Palace Hotel and Conventions, located in Foz do Iguaçu, a tourist Brazilian city close to the border with Argentina and Paraguay, which serves as a base for visits to Iguassu Falls and other attractions in the surroundings.
Symposium proposals can be submitted by teams of researchers, preferably of international composition, who wish to organize a thematic symposium within the event. Proposals that had been submitted and approved for the 2020 event are also expected to be resubmitted. “All symposium proposals will need to be sent by the deadline, including those that had been accepted for the 2020 event”, reinforces Professor Gustavo Dalpian, chair of the event. “The organizers of the symposia that had previously been approved will notice, when accessing the system, that the data from the 2020 proposal was automatically copied to the 2021 event. In this way, the organizers will be able to make the necessary adjustments and resubmit, but without having to enter everything again ”, he completes.
As in all editions of the B-MRS Meeting, the event will cover a wide range of topics in Materials Science and Technology, with a special emphasis on electronic materials, due to IUMRS-ICEM. Therefore, proposals for symposia are welcome on topics related to all types of materials, from design and synthesis to applications.
To submit a symposium proposal, just fill in English the form, available online at http://sbpmat.org.br/proposed_symposium/.
The symposia will be the main focus of the event along with plenary lectures, which will feature internationally renowned scientists who have already confirmed their presence: Alex Zunger (University of Colorado Boulder, USA), Edson Leite (LNNano, Brazil), Hideo Hosono (Tokyo Institute of Technology, Japan), John Rogers (Northwestern University, USA), Luisa Torsi (Università degli Studi di Bari “A. Moro”, Italy), Tao Deng (Shanghai Jiaotong University, China) and Thuc-Quyen Nguyen (University of California Santa Barbara, USA). The traditional Memorial Lecture “Joaquim da Costa Ribeiro” will be given by Cid Bartolomeu de Araújo (UFPE, Brazil).
Symposium proposals will be evaluated by the event committee, and, by the end of 2020, the list of approved symposia will be released. On February 1, 2021, the call for papers will be opened, for abstract submission within the thematic symposia. The symposium organizers will be responsible for the evaluation of the submitted abstracts and for the symposium schedule.
The joint event XIX B-MRS Meeting + IUMRS ICEM 2021 is coordinated by professors Gustavo Martini Dalpian (UFABC) in the general coordination, Carlos Cesar Bof Bufon (LNNANO) in the program coordination and Flavio Leandro de Souza (UFABC) as general secretary. The international committee comprises scientists from America, Asia, Europe and Oceania.
The latest editions of the B-MRS Meeting brought together between 1,100 and 2,000 participants from various countries around the world presenting their works within the symposia.
Go to the event website: https://www.sbpmat.org.br/19encontro/.