Interface limited hole extraction from methylammonium lead iodide films

Oskar Blaszczyk,Ifor D. W. Samuel,Muhammad T. Sajjad,Yiwei Zhang,Arvydas Ruseckas,Lethy Krishnan Jagadamma

doi:10.1039/c9mh01517e

Oskar Blaszczyk, Ifor D. W. Samuel + Show 4 more

Open Access

https://doi.org/10.1039/c9mh01517e

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Abstract

A new method is proposed to determine charge diffusion coefficient and transfer velocity to extraction layers. Hole diffusion coefficient in MAPbI3 is constant between 1016 – 1017 cm−3, a hallmark of band transport but overall extraction is interface limited.

Highlights

Perovskites have had tremendous success in recent years as materials for optoelectronic applications
We find that Nickel Oxide (NiO) shows faster hole extraction than PEDOT:PSS from the 300 nm thick perovskite film on the time scale of 300 ps which is independent of charge carrier density in the region of 1016–1017 cmÀ3
The interface with NiO is found to only slightly limit charge extraction rate at charge densities exceeding 1016 cmÀ3 as the extraction rate is fast and does not decrease with time. This is in contrast to PEDOT:PSS where we find the charge extraction rate to be slower, decreasing with time and dependent on charge density in the region 1016–1017 cmÀ3 which we interpret as charge accumulation at the interface

Summary

Introduction

Perovskites have had tremendous success in recent years as materials for optoelectronic applications. We find that NiO shows faster hole extraction than PEDOT:PSS from the 300 nm thick perovskite film on the time scale of 300 ps which is independent of charge carrier density in the region of 1016–1017 cmÀ3.

Results

Conclusion