Intrinsic and Extrinsic Charge Transport in CH3NH3PbI3 Perovskites Predicted from First-Principles.

Tianqi Zhao,Dong Wang,Jinyang Xi,Zhigang Shuai,Wen Shi

doi:10.1038/srep19968

Abstract

Both intrinsic and extrinsic charge transport properties of methylammonium lead triiodide perovskites are investigated from first-principles. The weak electron-phonon couplings are revealed, with the largest deformation potential (~ 5 eV) comparable to that of single layer graphene. The intrinsic mobility limited by the acoustic phonon scattering is as high as a few thousands cm2 V−1 s−1 with the hole mobility larger than the electron mobility. At the impurity density of 1018 cm−3, the charged impurity scattering starts to dominate and lowers the electron mobility to 101 cm2 V−1 s−1 and the hole mobility to 72.2 cm2 V−1 s−1. The high intrinsic mobility warrants the long and balanced diffusion length of charge carriers. With the control of impurities or defects as well as charge traps in these perovskites, enhanced efficiencies of solar cells with simplified device structures are promised.

Highlights

Comparable to that of single layer graphene
It has been shown that the simultaneous incorporation of spin-orbit coupling (SOC) effect and many-body effect can deliver a balanced description of band gaps for Pb- and Sn-based perovskites[14,15]
We have found that the electron-acoustic phonon couplings in lead iodide perovskites are weak, and the deformation potential is comparable to that of single layer graphene

Summary

Introduction

Comparable to that of single layer graphene. The hole mobility limited by the acoustic phonon scattering is larger than the electron mobility, and both are up to a few thousands cm[2] V−1 s−1. The charged impurity scattering starts to dominate at the impurity concentration of 1018 cm−3, and it lowers the electron mobility to 101 cm[2] V−1 s−1 and the hole mobility to 72.2 cm[2] V−1 s−1. The high intrinsic mobility warrants the long and balanced diffusion length of charge carriers. By defects and interface engineering, enhanced efficiencies of perovskites-based solar cells with simplified device structures are promised

Objectives

Methods

Results

Conclusion