Persistent photovoltage in methylammonium lead iodide perovskite solar cells

TL;DR

This study investigates charge recombination in methylammonium lead iodide perovskite solar cells, revealing persistent photovoltage and complex decay dynamics distinct from organic solar cells.

Contribution

It provides new insights into long-lived photovoltage and illumination-dependent recombination in perovskite solar cells, advancing understanding of their charge dynamics.

Findings

65-70% of photovoltage persists long-term

Recombination dynamics depend on illumination intensity

Distinct decay time domains compared to organic cells

Abstract

Open circuit voltage decay measurements are performed on methylammonium lead iodide (CH3NH3PbI3) perovskite solar cells to investigate the charge carrier recombination dynamics. The measurements are compared to the two reference polymer-fullerene bulk heterojunction solar cells based on P3HT:PC60BM and PTB7:PC70BM blends. In the perovskite devices, two very different time domains of the voltage decay are found, with a first drop on a short time scale that is similar to the organic solar cells. However, two major differences are also observed. 65-70% of the maximum photovoltage persists on much longer timescales, and the recombination dynamics are dependent on the illumination intensity.