Graduate Student Robert Hamburger

"Unlocking Potential of Antimony Sulfide Solar Cells by Understanding Ultra-Fast Electron Transport Mechanics"

Alternative energy sources are needed as a replacement to fossil fuels that are driving climate change across the planet. Solar energy through silicon-based devices provides a promising alternative that has so far not fully realized its potential. Meeting this promise will require other materials to augment and complement silicon-based devices. Promising complementary materials such as antimony sulfide are in development but have yet to fully realize their potential due to incomplete understanding of their properties. Understanding of the way electrons move through materials like antimony sulfide, especially when it is under operating conditions as a full device, are needed to unlock the full capabilities of these materials. Fabrication of completed solar cell devices using antimony sulfide as an absorbing layer allowed investigation of electron transport through the device. Transient absorption spectroscopy, a technique which uses laser pulses to study ultra-fast time scale events was utilized to examine these transparent solar cell devices. Combined with previous experiments on partially complete devices the mechanism of electron transport through the completed solar cell was determined. Optical modelling of the way light would differentially interact with the various material layers of the completed device helped to complete a full model of electron transport through the device. This model establishes a baseline of understanding of these antimony sulfide based transparent solar cells. Utilizing this as a platform, further experiments examining how these processes change when the cell is under operating conditions. Full insight into the mechanisms of electron movement in operating devices will allow informed design decisions to greatly improve device performance and efficiency.