Probing Interfaces and Stability of Halide Perovskite Semiconductors

Passivating interfaces in halide perovskite structures is a well-recognized strategy for enhancing performance in devices ranging from LEDs to solar cells to quantum light emitters. We study the semiconductor physics of halide perovskite photovoltaics under different stress conditions, from reverse bias stress to UV aging.  Using methods ranging from scanning probe microscopy to non-destructive photoluminescence imaging, we explore changes in band bending and carrier tunneling, electrochemical reactions, defect densities, and ultimately on performance and stability.  We study the effects of different interfaces on stability of perovskite diodes under reverse bias and reverse current conditions and UV exposure, and show that proper interface control can improve stability.  We demonstrate these improvements and trace their origins to specific interfaces in the device using operando physical probes.