Maximum efficiencies and performance limiting factors of inorganic and hybrid perovskite solar cells

TL;DR

This paper introduces a new formalism to accurately predict the absolute performance limits of various thin-film solar cells, revealing potential efficiencies and limiting factors for record-efficiency and hybrid perovskite solar cells.

Contribution

A novel formalism for precise efficiency limit prediction of thin-film solar cells, including hybrid perovskites, surpassing traditional models like Shockley-Queisser.

Findings

Over 30% efficiency possible with certain materials.

Hybrid perovskites face limitations from voltage and fill-factor losses.

New efficiency limits can better predict real-world solar cell performance.

Abstract

The Shockley and Queisser limit, a well-known efficiency limit for a solar cell, is based on unrealistic physical assumptions and its maximum limit is seriously overestimated. To understand the power loss mechanisms of record-efficiency cells, a more rigorous approach is necessary. Here, we have established a new formalism that can accurately predict absolute performance limits of solar cells in conventional thin film form. In particular, we have estimated the maximum efficiencies of 13 well-studied solar cell materials [GaAs, InP, CdTe, a-Si:H, CuInSe2, CuGaSe2, CuInGaSe2, Cu2ZnSnSe4, Cu2ZnSnS4, Cu2ZnSn(S,Se)4, Cu2ZnGeSe4, CH3NH3PbI3, HC(NH2)2PbI3] in a 1-um-thick physical limit. Our calculation shows that over 30% efficiencies can be achieved for absorber layers with sharp absorption edges (GaAs, InP, CdTe, CuInGaSe2, Cu2ZnGeSe4). Nevertheless, many record-efficiency polycrystalline solar cells, including hybrid perovskites, are limited by open-circuit voltage and fill-factor losses. We show that the maximum conversion efficiencies described here present new alternative limits that can predict the power generation of real-world solar cells.