Using pulsed mode scanning electron microscopy for cathodoluminescence studies on hybrid perovskite films

Giorgio Divitini,Rachel A Oliver,Gunnar Kusch,Jordi Ferrer Orri,Stuart Macpherson,Elizabeth M Tennyson,Samuel D Stranks,Caterina Ducati

doi:10.1088/2632-959x/abfe3c

Abstract

The use of pulsed mode scanning electron microscopy cathodoluminescence (CL) for both hyperspectral mapping and time-resolved measurements is found to be useful for the study of hybrid perovskite films, a class of ionic semiconductors that have been shown to be beam sensitive. A range of acquisition parameters is analysed, including beam current and beam mode (either continuous or pulsed operation), and their effect on the CL emission is discussed. Under optimized acquisition conditions, using a pulsed electron beam, the heterogeneity of the emission properties of hybrid perovskite films can be resolved via the acquisition of CL hyperspectral maps. These optimized parameters also enable the acquisition of time-resolved CL of polycrystalline films, showing significantly shorter lived charge carriers dynamics compared to the photoluminescence analogue, hinting at additional electron beam-specimen interactions to be further investigated. This work represents a promising step to investigate hybrid perovskite semiconductors at the nanoscale with CL.

Highlights

Halide perovskites have emerged as exceptional candidates for next-generation optoelectronic applications, as they are high-performing photoactive materials produced at lower costs and processed in a wider range of conditions than many other traditional semiconductors [1]
Optimization of the conditions for CL studies on hybrid perovskite films A series of 30 CL hyperspectral maps (CL maps) were taken at different positions of a hybrid perovskite film under various acquisition conditions
We have systematically studied the parameters affecting the acquisition of CL maps of hybrid perovskite (FA0.79MA0.16Cs0.05)Pb(I0.83Br0.17)3 films on glass, such as the effect of beam current, dwell time or beam mode

Summary

Introduction

Halide perovskites have emerged as exceptional candidates for next-generation optoelectronic applications, as they are high-performing photoactive materials produced at lower costs and processed in a wider range of conditions than many other traditional semiconductors [1]. Cathodoluminescence (CL) is a promising candidate for the investigation of emerging semiconductor materials [3]. In this technique, an electron beam excites a semiconductor causing emission of photons, which are subsequently collected and analysed. An electron beam excites a semiconductor causing emission of photons, which are subsequently collected and analysed This allows the optoelectronic properties of the material to be probed at a high spatial resolution

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