How Does Hysteresis Work? A Brief Investigation Based on Transient Photovoltage/Current Mapping

Perovskite solar cells (PSCs) are hindered by hysteresis-induced performance loss. To decode the underlying dynamics, we develop a transient-mapping technique (TMT) that synchronously resolves carrier recombination and extraction kinetics with spatiotemporal precision (240 μm spatial/0.5 ns temporal resolution). Based on the experiments, we have revealed that the horizontal electric field gradients correlate with perovskite thickness variations, generating localized charge barriers that introduce a lateral movement of current on the surface of the device rather than the current output. On the other hand, the recombination center mapping identifies trapped-hole densities up to 1.6× 10 17 cm −3 at inhomogeneous HTL/perovskite interfaces, which caused charge loss when they cross interfaces. Meanwhile, the accumulation of charge carriers increased the differential capacitance (DC), and experimental results showed that the hotspot DC significantly blocks carrier transport across layers, as evidenced by charge extraction mapping, which finally enhanced the hysteresis effect. This method provides direct operando evidence linking hysteresis to fabrication-induced inhomogeneities and enables real-time quality control during PSC manufacturing.