Insights Into the Microscopic and Degradation Processes in Hybrid Perovskite Solar Cells Using Noise Spectroscopy

Abstract

We report a clear correlation of the features observed in photocurrent noisefluctuations to the performance parameters of hybrid perovskite solar cells. The general trend of increasing noise amplitude which spreads over a wider range of frequency as a function of aging is established. High-resolution spatial mapping of the photocurrent in typical devices and the associated variation of the noise spectrum confirms the underlying trend.

Low-Frequency Carrier Kinetics in Perovskite Solar Cells

“…Noise amplitude is sometimes used as a predictor for solar cell performance metrics. 23 However, additional correlation with FF here suggests a common role of interfacial recombination in decreasing FF and increasing noise amplitude. Recently, processing advances have achieved high efficiency (>20%) and high quasi-Fermi level splitting using PTAA HTLs in solar cells.…”

Enhanced Stability and Optimized Morphology Induced by Electric‐Field‐Assisted Annealing of Bulk Heterojunction Solar Cells

“…In general, lower noise amplitude of the fluctuations in the I ph ( t ) time series correlates with higher efficiency and improved stability of the device . The photocurrent fluctuation studies of EFTA treated and control devices confirm the underlying trend.…”

“…A value of γ ≈ 1.2 indicative of stable organic BHJ solar cells have been obtained in this study (Table S4, Supporting Information). [20b] In general, higher NPSD in UA, TA, high‐EF(+), and high‐EF(−) devices show increased charge transport barrier and recombination processes prevailing in the system. The decrease in noise by three order of magnitude (2.6 × 10 −15 Hz −1 at 2 Hz) observed in low‐EF(−) treated device in comparison with UA device (6.6 × 10 −12 Hz −1 at 2 Hz) is consistent with the increased stability and enhanced performance.…”

“…The NPSD typically follows 1/ f γ behavior. The exponent γ and the frequency range covering the 1/ f behavior have been interpreted in terms of microscopic parameters . The trapping and recombination events in the bulk of the semiconductor lead to a typical γ in the range of 0.8–1.4 in conventional devices .…”

Fully Air‐Processed Carbon‐Based Efficient Hole Conductor Free Planar Heterojunction Perovskite Solar Cells With High Reproducibility and Stability

“…Without doubt, the usage of these costly materials increases the preparation cost of PVSCs immensely . Moreover, organic HTMs always show hydrophilic behavior, and could interact with noble metal through ionic migration process, which will destroy the stability of PVSCs tremendously. Therefore, it hampers large‐scale commercial application of these conventional PVSCs.…”