Absolute Quantification of Photo-/Electroluminescence Imaging for Solar Cells: Definition and Application to Organic and Perovskite Devices

Abstract

This Article first addresses the need for intrinsic electroluminescence and photoluminescence imaging characterizations. Both are always performed in arbitrary units preventing system comparisons as a function of chemistry, processing, aging time, or between different authors. We propose a simple equation to extract the intrinsic contribution of the sample in a broad range of measurement conditions. This work will enable authors to vary the measurement features to optimize the outcomes in resolution/saturation for photonic characterization. This method will also help model the electroluminescence and photoluminescence mechanisms with quantitative data. It should therefore be possible to carry out a much broader and systematic study to help the future development of solar cells. The developed quantification method was applied to organic and perovskite solar cells. According to the selected analysis, filters must be added to isolate the photovoltaic mechanisms coming from the active layer itself from that of the active layer–electrode interfaces. It was even possible to compare the organic and perovskite technologies and, thereby, better appreciate their functioning principle and its impact on the overall photovoltaic performances.

Influence of Chloride/Iodide Ratio in MAPbI3-xClx Perovskite Solar Devices: Case of Low Temperature Processable AZO Sub-Layer

“…Moreover, TiO 2 based devices are known to suffer from critical deterioration under ultraviolet illumination. Several studies have already been conducted with other metal oxides compatible with low temperature processes, specifically ZnO [9,10] and SnO 2 [11,12]. SnO 2 demonstrated a great transmission rate and an elevated electron mobility, with adapted energy band gap and relatively deep conduction band level.…”

Degradation Mechanisms in a Mixed Cations and Anions Perovskite Solar Cell: Mitigation Effect of the Gold Electrode

“…The so-called LBIC measurement is a tool of choice to study the local performance of the solar cells and thereby propose degradation mechanisms. 36 LBIC maps were recorded and are presented in Figure 2a.…”

“…For this reason, in this study, the solar cells were characterized in the open-circuit condition. Furthermore, PL images (Figure 3b) are presented using an absolute quantification method recently developed in our lab, 36 allowing to better compare data in case of a change in acquisition parameters. Following this, it is now possible to track and compare different PV devices during aging campaigns.…”

“…Partial stacks were processed to assess the perovskite degradation mechanisms assisted by surrounding layers and the effects that originate at the interfaces. Together with traditional microstructural, optical, optoelectronic characterizations, advanced imaging characterizations (some of which have been recently developed within the laboratory consortium 36 ) have also been used to track the degradation phenomena [laser-beam-induced current (LBIC) mapping, photoluminescence (PL) imaging, and visual observations]. The major outcome of this broad series of experiments is that the metallic gold electrode significantly contributes to the protection of the devices not only against ambient atmosphere, as one would expect from a dense layer, 37 but also against thermal degradation.…”

Contactless Series Resistance Imaging of Perovskite Solar Cells via Inhomogeneous Illumination

“…ELi and PLi have been used to study charge‐carrier recombination and resistive losses, [ 36 ] detect pinholes, [ 37 ] assess the quality and uniformity of the perovskite layer, [ 14,38 ] and so on. [ 39,40 ] They have been also used to image i V OC , [ 41–45 ] spatial variation of the optical bandgap, [ 46 ] current transportation, [ 12,44 ] and R s . [ 47,48 ]…”