A Review and Perspective on Cathodoluminescence Analysis of Halide Perovskites

Abstract

Halide perovskite solar cells have achieved a certified efficiency of 25.2%, surpassing CdTe and CIGS, which have long been regarded as the most-efficient thin-film photovoltaic materials. As this exciting class of materials continues to mature, researchers will require characterization techniques capable of exposing the interplay between structure, chemistry, and optoelectronic properties to inform processing strategies and increase both device efficiencies and long-term stability. Cathodoluminescence microscopy is an ideal technique to provide such information due to the high spatial resolution and robust optical information acquired. Here, the current body of work related to cathodoluminescence analysis of halide perovskite materials for optoelectronic applications is surveyed. This review demonstrates how cathodoluminescence can monitor degradation due to environmental stressors, phase segregation resulting from material processing, and other halide perovskite-centric material issues. A persistent concern associated with e-beam-based analysis of halide perovskites is what effect the electron beam has on the material properties being probed.Addressing this, a detailed discussion is provided on the origin of the cathodoluminescence signal and a review of studies focused on revealing changes in the properties of halide perovskites resulting from This article is protected by copyright. All rights reserved. e-beam excitation. Finally, a perspective on future opportunities to expand the role of cathodoluminescence analysis for halide perovskites is provided.

Two birds with one stone: dual grain-boundary and interface passivation enables >22% efficient inverted methylammonium-free perovskite solar cells

“…This enhancement is attributed to the passivation of various recombination centres in the grain boundaries and/or at the surface of the perovskite layer. 126 Importantly, an additional CL peak at ~620 nm appears, which cannot be related to either the 3D perovskite phase or the PbI 2 -rich phase. We find similar peaks in PL measurements of GBP&SP films as well as for SP films when using a higher PEACl concentration of 3 mg/ml (see Fig.…”

“…To gain a better understanding about the phase or composition of the small and large bright grains observed in SEM at the surface of the perovskite films as well as their potential relevance in the context of this work, we carry out CL measurement. 126 For the Ref film, the grains which appear darker in SEM (highlighted by a green circle in Fig. 4) exhibit higher CL intensities (Fig.…”

Small grains as recombination hot spots in perovskite solar cells

“…Cathodoluminescence (CL) microscopy probes the radiative decay of charges generated by exposure to an electron beam and has been utilized in many studies on perovskite materials. 53 While the effect of tuning the grain size has not been systematically investigated using CL microscopy, conflicting results have been observed regarding the luminescence intensity of grains and grain boundaries. For example, Bischak et al observed a reduced CL intensity at grain boundaries and a large variation of grain-to-grain luminescence, with many large grains-surprisingly-appearing dark.…”

Understanding the Role of Grain Boundaries on Charge‐Carrier and Ion Transport in Cs2AgBiBr6 Thin Films

“…The acceleration voltage used in this study was 3 kV, corresponding to a penetration depth of 67 nm according to Monte Carlo simulations using Monte Carlo Casino (Figure S3, Supporting Information). [35] Thus, the interaction volume size in CL is significantly smaller than in confocal PL, [36] providing sufficient spatial resolution to differentiate between the grain boundary and interior.…”