Nanoscale imaging of photocurrent in perovskite solar cells using near-field scanning photocurrent microscopy

Published: June 10, 2018

Author(s)

Dongheon Ha, Yohan Yoon, Ik Jae Park, Paul M. Haney, Nikolai B. Zhitenev

Abstract

We study photocurrent generation and collection of methylammonium lead iodide perovskite solar cells with nanoscale resolution using a near-field scanning photocurrent microscopy (NSPM) technique. For NSPM measurements, we employ a non-contact mode atomic force microscopy probe with an attached optical fiber coated with Cr/Au metal. We observe an increased photocurrent at grain boundaries in samples annealed at moderate temperature (100 °C); however, the opposite spatial pattern is observed in samples annealed at higher temperature (130 °C). Combining the NSPM results with other characterization techniques such as electron microscopy, X-ray diffraction, and quantum efficiency measurements, we show that the cause of the photocurrent contrast is the material inhomogeneity and the dynamics of lead iodide. The NSPM technique is further used to establish the mechanism of the cell degradation under extended light illumination.
Proceedings Title: 45th IEEE Photovoltaic Specialists Conference
Conference Dates: June 11-15, 2018
Conference Location: Waikoloa, HI
Conference Title: 45th IEEE Photovoltaic Specialists Conference (7th World Conference on Photovoltaic Energy Conversion)
Pub Type: Conferences
Created June 10, 2018, Updated April 12, 2019