Quantifying Efficiency Loss of Perovskite Solar Cells by a Modified Detailed Balance Model

TLDR

The study develops a modified detailed balance model to quantify efficiency losses in perovskite solar cells. The model incorporates light‑absorption‑dependent short‑circuit current, modified carrier transport in contact and transport layers, and recombination and photon‑recycling effects on open‑circuit voltage. The model shows that for 19 % efficient cells, optical loss (25 %), non‑radiative recombination (35 %), and ohmic loss (35 %) are the main losses, with optical loss rising to 40 % in thin‑layer designs and transport‑layer misconfigurations adding >15 % loss, indicating that interface recombination, ohmic loss, and leakage must be reduced to approach the 31 % limit.

Abstract

A modified detailed balance model is built to understand and quantify efficiency loss of perovskite solar cells. The modified model captures the light-absorption dependent short-circuit current, contact and transport-layer modified carrier transport, as well as recombination and photon-recycling influenced open-circuit voltage. Our theoretical and experimental results show that for experimentally optimized perovskite solar cells with the power conversion efficiency of 19%, optical loss of 25%, non-radiative recombination loss of 35%, and ohmic loss of 35% are the three dominant loss factors for approaching the 31% efficiency limit of perovskite solar cells. We also find that the optical loss will climb up to 40% for a thin-active-layer design. Moreover, a misconfigured transport layer will introduce above 15% of energy loss. Finally, the perovskite-interface induced surface recombination, ohmic loss, and current leakage should be further reduced to upgrade device efficiency and eliminate hysteresis effect. The work contributes to fundamental understanding of device physics of perovskite solar cells. The developed model offers a systematic design and analysis tool to photovoltaic science and technology.