Evgeniia Gilshtein

Project title

Co-Engineering of Multi-Dimensional Interfaces for Thin-Film Solar Cells (MultiDCell)

What is your project about?

Thin-film solar cells can be lightweight, flexible and made from abundant materials, but their efficiency is still limited by energy losses at the interfaces in the device. How can we achieve light to electricity conversion efficiencies greater than 10%, towards the theoretical limit, which is above 28%? This project will develop a new solar-cell architecture that combines three types of dimensional nanomaterials: quantum dots – 0D, antimony chalcogenides – quasi-1D, and ultra-thin 2D layers. Each material has a specific role: guiding crystal growth, transporting electrical charges and reducing defects. By combining systematic experiments and materials characterization with theoretical modelling, we will identify how these interfaces affect charge transport and solar-cell performance. The long-term aim is to enable more efficient, stable and sustainable thin-film solar cells which can be used not only for outdoor, but also for indoor IoT applications.

How did you become interested in your particular field of research?

My interest in physics began in high school, after an inspiring first lesson with physics teacher who filled the classroom with demonstrations and experiments. That experience made me want to become a scientist. My grandfather, the only engineer in my family, also inspired my curiosity about how things are made and how materials work, which later led me toward materials science. During MSc, PhD and postdoctoral work, I became fascinated by nanomaterials, such as nanowires and nanoparticles, because their properties can be tuned by controlling their structure, surfaces and interfaces. How great that tiny nanostructures can be used as building blocks for very different devices, from sensors and electrodes to energy-storage and energy-conversion systems. This naturally brought me closer to sustainable energy technologies, particularly solar cells. Performance losses in such devices motivated me to combine nanomaterials science with photovoltaics, using precise interface engineering and my broad prior knowledge in the field.

What are the scientific challenges and perspectives in your project?

One main scientific challenge is to control what happens at the nanoscale interfaces between the layers in a thin-film solar cell. These interfaces often contain defects where electrical charges recombine before they can be collected as electrical current, which limit device efficiency. In this project, we will test whether nanomaterials with different shapes, sizes and dimensions can solve this problem together: quantum dots will guide the growth of the light absorber with efficient pathways for charge transport, and transport layers will passivate defects. The key perspective is not only to improve solar-cell performance, but to understand why it improves by linking interface structure, charge transport and device efficiency.

What is your estimate of the impact, which your project may have to society in the long term?

In the long term, this project may contribute to cheaper, lighter and more sustainable solar-energy technologies. Thin-film solar cells can potentially be produced with less material and energy than conventional silicon solar cells, but their efficiency and stability must improve before they can become broadly competitive. By understanding how interfaces control losses in a thin-film solar cell, this project can provide design principles for making better devices from earth-abundant materials. If successful, the knowledge gained could support the development of stable thin-film solar cells for buildings, lightweight electronics, helping accelerate the transition to renewable energy.

Which impact do you expect the Sapere Aude programme will have on your career as a researcher?

The Sapere Aude programme would be a transformative step in my career. It would allow me to establish an independent research direction in thin-film photovoltaics, build my own small research team, and develop the scientific leadership for the team of one more PhD student (along with the current one PhD) and one Postdoc under my direct supervision. I am to transition to a professor role in materials science for energy technologies at the end of my DTU Tenure Track Program. The grant would also give me the freedom to pursue a high-risk, high-gain idea that cannot be fully realized without such an independent project. It would also help me position myself internationally as a leading researcher in sustainable energy materials through the proposed collaborations.