Circular Photogalvanic Effect in Organometal Halide Perovskite CH$_3$NH$_3$PbI$_3$

TL;DR

This study investigates the circular photogalvanic effect in CH$_3$NH$_3$PbI$_3$ perovskite, showing its potential to probe inversion symmetry and relate to high solar cell efficiency.

Contribution

It demonstrates the calculation of photocurrent density related to the circular photogalvanic effect in perovskite, linking inversion symmetry breaking to material properties.

Findings

Photocurrent density is about 10^{-9} A/W in non-centrosymmetric structures.

The effect depends on inversion symmetry breaking and can be tuned by photon energy.

Measurement of the effect can clarify the presence of inversion symmetry in the material.

Abstract

We study the circular photogalvanic effect in the organometal halide perovskite solar cell absorber CH$_3$NH$_3$PbI$_3$. For crystal structures which lack inversion symmetry, the calculated photocurrent density is about $10^{-9}$ A/W, comparable to the previously studied quantum well and bulk Rashba systems. Because of the dependence of the circular photogalvanic effect on inversion symmetry breaking, the degree of inversion asymmetry at different depths from the surface can be probed by tuning the photon energy and associated penetration depth. We propose that measurements of this effect may clarify the presence or absence of inversion symmetry, which remains a controversial issue and has been argued to play an important role in the high conversion efficiency of this material.