Electrochemical Screening of Contact Layers for Metal Halide Perovskites

TL;DR

This paper demonstrates electrochemical testing methods like cyclic voltammetry and chronoamperometry to evaluate contact layers in perovskite solar cells, aiding process development and quality control.

Contribution

It introduces simple electrochemical tests that correlate with device performance and interfacial properties, facilitating scalable screening of contact layers in perovskite photovoltaics.

Findings

Electrochemical tests correlate with device performance.

Screening methods are fast, reliable, and scalable.

Tests reveal interfacial defect impacts and chemical composition.

Abstract

Optimizing selective contact layers in photovoltaics is necessary to yield high performing stable devices. However, this has been difficult for perovskites due to their complex interfacial defects that affect carrier concentrations in the active layer as well as charge transfer and recombination at the interface. Using vacuum thermally-evaporated tin oxide as a case study, we highlight electrochemical tests that are simple yet screen device-relevant contact layer properties, making them useful for process development and quality control. Specifically, we show that cyclic voltammetry and potentiostatic chronoamperometry correlate to key performance parameters in completed devices as well as other material/interfacial properties relevant to devices such as shunt pathways and chemical composition. Having fast, reliable, scalable, and actionable probes of electronic properties is increasingly important as halide perovskite photovoltaics approach their theoretical limits and scale to large-area devices.