Bias-Dependent Dynamics of Degradation and Recovery in Perovskite Solar Cells

Abstract

Degradation of perovskite solar cells (PSCs) is often found to be partially or fully reversible when the cells are allowed to recover in the dark. Unlike the dynamics of degradation, knowledge about the dynamics of PSC cell recovery is very limited. Here, we demonstrate that the PSC recovery strongly depends on the electrical bias conditions during the light-induced degradation and that it can be manipulated by applying an external electrical bias during the recovery phase. Investigation of the recovery dynamics allows us to analyze the degradation mechanisms in detail. More specifically, we aged a mixed-cation mixed-halide PSC with a n-i-p structure under illumination in open-circuit (OC) or short-circuit (SC) conditions, and periodically measured their characteristics during the recovery. PSCs aged in SC degrade faster and fully recover after the light is switched off, while the performance of the cells aged in OC does not recover but instead further decreases after the light is switched off (“drop-in-dark” effect). With the use of transient photoluminescence, secondary ion mass spectrometry, and drift-diffusion-based simulations, we hypothesize that extrinsic ion migration causes the drop-in-dark effect, by forming an electron extraction barrier at the metal oxide electron transport layer. The applied bias alleviates this effect. Our results are relevant for gaining a deeper understanding of the multiple degradation mechanisms present in perovskite solar cells, and for finding a practical way to assist their recovery.

Toward Semitransparent PIN-type Perovskite Solar Cells with Sputtered ITO Electrode: Architecture and Process Optimizations

“…Such a “maturation” phenomenon could sometimes be observed in the literature. Despite it not being fully understood at the present time, this seems to be associated with concomitant outcomes of light or field induced movement of ions with structural rearrangement within the perovskite layer during aging. − In our case, this maturation phenomenon was also observed even when an important initial degradation occurred after integration of ITO (from our recipe B), leading to a recovery in efficiencies. To our knowledge, it is the first assessment to be reported of such a “damage/recovery” behavior with sputtered ITO on perovskite solar cells.…”

Functionalized MXene/Halide Perovskite Heterojunctions for Perovskite Solar Cells Stable Under Real Outdoor Conditions

“…To scrutinize in more detail on the performance of the HP:H3pp/MXene:H3pp heterojunction in a PSC, we carried out an outdoor stability analyses for > 600 h by holding the devices at their open circuit voltage [ 53 ] and measuring their current‐voltage (JV) every 20 min, see Figure 8 . To ensure reproducibility, between 3 and 4 devices for each category were analyzed simultaneously, including the control PSC with no passivation (Figure 8a, black), the PSCs with the MXene:H3pp (Figure 8a, blue), the HP:H3pp/d‐MXene (Figure 8a, red) and the HP:H3pp/MXene:H3pp (Figure 8a, green).…”

Forty-two days in the SPA, building a stability parameter analyzer to probe degradation mechanisms in perovskite photovoltaic devices

“…However, we currently nd the JV curves to provide signicant insight and are not condent in the non-perturbative nature of other possibly insightful measurements. In this direction, given that substantial literature has shown that applied voltage can affect perovskite degradation, [18][19][20] even the JV sweeps themselves could be altering degradation.…”