Hot carriers in metal halide perovskites

The greatest challenge of our time is the transformation to sustainability of the global energy system. Solar cells are a crucial ingredient in this challenge, and boosting their efficiency would accelerate the entire process. The goal of third-generation solar cell technology is to do so by overcoming the Shockley-Queisser limit. 

The Shockley-Queisser limit is the theoretical efficiency limit for a single solar cell and strongly limits the potential of solar cells. Overcoming this limit represents a significant scientific challenge, and researchers have developed several innovative approaches. A hot carrier solar cell is a proposed solution, focusing on using heat effectively to enhance its power efficiency. By doing so, solar cell efficiencies could potentially be doubled, achieving numbers higher than 50%.

The single most important ingredient for a hot carrier solar cell is an active layer material that exhibits very long cooling times. Recent experimental reports on metal halide perovskites show promising cooling times, however, the reasons behind the slow cooling in metal halide perovskites are not well understood and more scientific understanding is very much needed.

In his thesis, Tim Faber investigates what causes carrier relaxation times in metal halide perovskites to be so unusually long. He unravels the different stages and fundamental interactions of the cooling process. By doing so, Faber us ultimately able to answer why metal halide perovskites are indeed special and confirms that slow cooling in these materials can be understood from a theoretical perspective. The results of the thesis contribute to designing a roadmap to the successful creation of a hot carrier solar cell.

Proefschrift: https://hdl.handle.net/11370/66b2a2f0-f9ae-43d2-862b-dcaa0232b3a1