The Polymer Society of Korea

Abstract

Perovskites offer superior photoelectric properties and low-cost processability, making them promising alternatives to conventional photodetector materials like Si and GaAs. However, defects at grain boundaries and ion migration in polycrystalline films generate trap states, causing high dark currents that limit device performance. This study presents a passivation strategy using a functional polymer to suppress these defects. Spectroscopic analyses confirmed strong polymer-perovskite interactions, while Thermal Admittance Spectroscopy (TAS) revealed a significant reduction in trap density of states (tDOS). Consequently, the passivated photodetector achieved a ten-fold reduction in dark current while maintaining excellent response time and linear dynamic range (LDR). The device demonstrated clear feasibility for optical communication, showing great promise as a broadband photodetector for future systems.