Study of a Lead-Free Perovskite MA3Bi2Br9 Narrowband Photodetector for Blue-Light Detection

Abstract

Narrowband photodetection is crucial for various applications, including machine vision, bioimaging, and environmental monitoring. While lead-based perovskites offer promising properties, their toxicity and instability limit their practical applications. Here, we report a high-performance narrowband photodetector (PD) based on lead-free perovskite MA3Bi2Br9 single crystal. By employing the charge collection narrowing (CCN) mechanism, we realized a device exhibiting a pronounced peak response centered at 470 nm, characterized by a narrow full-width at half-maximum (FWHM) of merely 24 nm. The detector exhibits a high responsivity of 0.102 mA/W and a specific detectivity of $2.21\times 10^{8}$ Jones at 15 V bias. Additionally, it demonstrates a high spectral rejection ratio (SRR) of 34 for 470-nm light relative to 510-nm light. To quantify blue-light hazards, we established a numerical relationship between weighted irradiance and photocurrent. Our results highlight the potential of lead-free perovskite-based PDs for practical applications in narrowband detection and environmental monitoring.