Numerical simulation and performance analysis of self-powered Cs₂TeI₆ photodetector for visible light communication receivers
摘要
Self-powered photodetectors with high responsivity(R), detectivity(D*), and external quantum efficiency (EQE) are key components for energy-efficient visible light communication (VLC) receiver systems. In this work, 8 Cs-based perovskite materials are systematically assessed using density functional theory (DFT) to evaluate their optical properties in the visible spectral region. Among the investigated candidates, Cs₂TeI₆ exhibits the favourable optical characteristics-strong visible-light absorption and enhanced dielectric response, indicating superior photocarrier generation potential. Based on material selection, a self-powered photodetector employing Cs₂TeI₆ is designed and analysed using SCAPS-1D simulations with an FTO/Cs₂TeI₆/Au architecture, focusing on energy band alignment, built-in electric field formation, and carrier transport under zero-bias conditions. The simulated device demonstrates broadband photo-response from 300 to 700 nm, with peak performance at 400 nm, where the EQE approaches 90%. At the same wavelength, the photodetector achieves a maximum R of 490 mA/W and a peak D* of 7.8 × 10¹⁰ Jones, highlighting efficient photon-to-carrier conversion and low-noise operation. By integrating first-principles material screening with device-level simulation, this study provides a rational and application-driven design strategy for lead-free, self-powered perovskite photodetectors tailored for next-generation visible light communication receiver technologies.