The Sobering Reality of Perovskite/Si Tandem Solar Cells under Realistic Operating Conditions

TL;DR

This study models perovskite/Si tandem solar cells under real-world conditions, revealing that their efficiency gains are limited without further material and device optimization, despite promising laboratory results.

Contribution

It provides a detailed performance model incorporating real-world losses, highlighting the need for improved materials and design for practical high-efficiency tandem solar cells.

Findings

Tandem cells outperform Si under standard test conditions.

Real-world conditions reduce tandem cell efficiency gains.

Optimization can increase efficiency by up to 14% absolute.

Abstract

Perovskite/Si tandem solar cells have the potential to considerably out-perform conventional solar cells. Under standard test conditions, perovskite/Si tandem solar cells already outperform the Si single junction. Under realistic conditions, however, as we show, those tandem solar cells are hardly more efficient than the Si cell alone. We model the performance of realistic perovskite/Si tandem solar cells under real-world climate conditions, by incorporating parasitic cell resistances, non-radiative recombination, and optical losses into the detailed-balance limit. We show quantitatively that optimizing these parameters in the perovskite top cell, perovskite/Si tandem solar cells reach an efficiency advantage of up to 14% absolute, even while leaving the Si cell untouched. Despite the rapid efficiency increase of perovskite solar cells, our results emphasize the need for further material development, careful device design, and light management strategies, all necessary for highly efficient perovskite/Si tandem solar cells.