Procedure Based on External Quantum Efficiency for Reliable Characterization of Perovskite Solar Cells

Abstract

Perovskite solar cells (PSCs) have the potential for widespread application, but challenges remain for a reliable characterization of their performance. Standardized protocols for measuring and reporting are still debated. Focusing on the short circuit current density (J SC), current–voltage characteristics (J–V) and external quantum efficiency (EQE) are collected to estimate the parameter. Still, they often provide a mismatch above 1 mA cm−2, resulting in a possible 5% or higher error. Combining experimental data and optical simulations, it is demonstrated that the EQE can provide a reliable estimate of the J SC that could otherwise easily be overestimated by J–V. With access to the internally transmitted light through simulations, an upper limit for EQE is defined depending on the front layers. Details on the origin of the spectral shape and contributions to the optical losses are obtained with further optical simulations, providing hints for cell optimization to achieve a photocurrent gain. The authors use solution‐processed n‐i‐p PSCs with triple‐cation mixed‐halide absorbers as demonstrators and ultimately come to the proposal of an upgrade of the present best practices in PSC efficiency measurements. Still, the approach and conclusions are general and apply to cells with all designs and chemical formulations.

oCVD PEDOT-Cl Thin Film Fabricated by SbCl5 Oxidant as the Hole Transport Layer to Enhance the Perovskite Solar Cell Device Stability

“…However, for both of the PSC devices, J sc,JV values were consistently higher than the J sc,EQE values. This discrepancy is a known occurrence in PSC devices and has been extensively discussed in the literature. − Possible reasons for this difference include challenges in calibrating the EQE setup, disparities in time scales for the two measurements, long-term sample degradation and interfacial alterations for EQE measurement, scan rate and direction bias for J sc,JV , the anomalous hysteresis effect, and the impact of preconditioning measurements on EQE. , The superior performance of perovskite devices utilizing oCVD PEDOT-Cl as the HTL, in comparison to devices employing PEDOT:PSS-DMSO, can be attributed to its exceptional optoelectronic characteristics. These include a significantly enhanced electrical conductivity and a higher work function which yields a reduced contact barrier at the interface between the perovskite layer and the HTL as a consequence of the minimized gap between the HOMO energy level of oCVD PEDOT-Cl and valence band of the perovskite active layer.…”

Exploring the Effect of Kesterites and Zinc‐Based Charge Transport Materials on the Device Performance and Optoelectronic Properties of FAPbI3Perovskite Solar Cells

“…To ensure high QE, it is preferred to have the front layer of a large bandgap (high transmissivity) with an active layer of a low bandgap (high absorption) in the PSC structures. [ 14–16 ] Figure 4 a shows the effect of ETL on the QE of the PSC while Figure 4b presents the effect of HTL on the QE.…”

“…To ensure high QE, it is preferred to have the front layer of a large bandgap (high transmissivity) with an active layer of a low bandgap (high absorption) in the PSC structures. [14][15][16] Figure 4a shows the effect of ETL on the QE of the PSC while Figure 4b presents the effect of HTL on the QE. From the results, it can be seen that as the transmissivity of the ETL increases, the QE of the PSC also increases (Figure 4a) achieving a maximum near 400 nm.…”

Highly Efficient and Robust Ternary All‐Polymer Solar Cells Achieved by Electro‐Active Polymer Compatibilizers

“…The J sc values calculated from external quantum efficiency (EQE) measurement were consistent with the measured J sc values of each all‐PSC within a margin of error of 4% (Figure 3d). [ 22 ] In particular, with the incorporation of P1 and P2, the ternary blends featured higher EQE responses than PBQx‐TF:PYIT binary blend in the wavelength range of 550–650 nm, which corresponds to the main absorption region of P1 and P2 (Figure 1b).…”