High-Performance Perovskite Photodetector With Multi-Peak Response Under Edge Illumination Configuration

In this letter, the operational characteristics and performance of perovskite photodetectors were systematically studied under edge illumination, revealing significant performance enhancements in a CsFAPbI3 perovskite device compared to vertical illumination. At 0 V bias, responsivity improved from 8.3 A/W to 214 A/W, and detectivity increased from <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1.67 \times \; 10^{{12}}$ </tex-math></inline-formula> to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1.49 \times \; 10^{{13}}$ </tex-math></inline-formula> Jones compared to vertical illumination. The lateral light penetration resulted in distinct and repeatable multi-peak response patterns over a frequency range of 0.2-5 kHz and light intensities of 0.68-6.56 mW/cm2. The dynamic response of the device was effectively modeled as a second-order system, demonstrating its potential for secure communication applications. This setup also enabled precise control over the photodetector’s size at small dimensions by simply adjusting the thickness, achieving an active area of just <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$10^{-{5}}$ </tex-math></inline-formula> cm2 under edge illumination. This study underscores the promise of edge illumination for optimizing perovskite photodetectors and is currently under further investigation to broaden its applicability.