Interplays between charge and electric field in perovskite solar cells: charge transport, recombination and hysteresis

TL;DR

This paper systematically investigates how charge and electric field interactions affect charge transport, recombination, and hysteresis in perovskite solar cells through experiments and theoretical analysis.

Contribution

It reveals the roles of light-induced carrier concentration, junction electric fields, and ion migration in charge dynamics and hysteresis behavior in perovskite solar cells.

Findings

Light illumination increases carrier concentration, enhancing recombination.

Junction electric field influences charge collection and distribution.

Ion migration-induced static charge impacts electric field and hysteresis.

Abstract

Interplays between charge and electric field, which play a critical role in determining the charge transport, recombination, storage and hysteresis in the perovskite solar cell, have been systematically investigated by both electrical transient experiments and theoretical calculations. It is found that the light illumination can increase the carrier concentration in the perovskite absorber, thus enhancing charge recombination and causing the co-existence of high electric field and free carriers. Meanwhile, the cell shows a similar charge storage and junction mechanism to that of the multicrystalline silicon solar cell, where the junction electric field determines the charge collection and distribution. Furthermore, it is demonstrated that the static charge of both the doping and defect coming from ion (vacancy) migration can significantly influence the electric field inside the cell, thus affecting the charge collection and recombination, which could be the origins for the widely-concerned hysteresis behaviors.