Device Engineering of Perovskite Solar Cells to Achieve Near Ideal Efficiency

TL;DR

This paper combines theoretical calculations and simulations to explore the efficiency limits of perovskite solar cells, revealing design strategies to surpass current performance barriers despite recombination effects.

Contribution

It provides a detailed analysis of efficiency limits and identifies physical mechanisms affecting device performance, proposing designs to achieve over 25% efficiency and 85% fill factor.

Findings

Efficiency limit calculations including recombination effects

Identification of bias-dependent carrier collection mechanisms

Device designs achieving >25% efficiency and 85% fill factor

Abstract

Despite the exciting recent research on perovskite based solar cells, the design space for further optimization and the practical limits of efficiency are not well known in the community. In this manuscript, we address these aspects through theoretical calculations and detailed numerical simulations. Here, we first provide the detailed balance limit efficiency in the presence of radiative and Auger recombination. Then, using coupled optical and carrier transport simulations, we identify the physical mechanisms that contribute towards bias dependent carrier collection, and hence low fill factors of current perovskite based solar cells. Curiously, we find that while Auger recombination is not a dominant factor at the detailed balance limit, it plays a significant role in device level implementations. Surprisingly, our device designs indicate that it is indeed possible to achieve efficiency and fill factor greater than 25% and 85%, respectively - even in the presence of Auger recombination.