Exploiting Electrical Transients to Reveal Charge Loss Mechanism of Junction Solar Cells

TL;DR

This paper introduces a new methodology using electrical transients to analyze charge loss mechanisms in various junction solar cells, providing insights into their dynamic physics and defect properties.

Contribution

A novel approach to quantify charge loss and defect properties in junction solar cells, surpassing the limitations of traditional tail-state frameworks, applicable to multiple photovoltaic systems.

Findings

Successfully applied to silicon, Cu2ZnSn(S, Se)4, and perovskite solar cells.

Revealed charge loss mechanisms at bulk and interface levels.

Provided a universal methodology for photovoltaic device analysis.

Abstract

Electrical transients enabled by optical excitation and electric detection provide a distinctive opportunity to study the charge transport, recombination and even the hysteresis of a solar cell in a much wider time window ranging from nanoseconds to seconds. However, controversies on how to exploit these investigations to unravel the charge loss mechanism of the cell have been ongoing. Herein, a new methodology of quantifying the charge loss within the bulk absorber or at the interfaces and the defect properties of junction solar cells has been proposed after the conventional tail-state framework is firstly demonstrated to be unreasonable. This methodology has been successfully applied in the study of commercialized silicon and emerging Cu2ZnSn(S, Se)4 and perovskite solar cells herein and should be universal to other photovoltaic device systems with similar structures. Overall, this work provides an alluring route for comprehensive investigation of dynamic physics processes and charge loss mechanism of junction solar cells and possesses potential applications for other optoelectronic devices.