Impact of luminescence coupling on two-terminal dual-band photodetector performance: A comparative modeling study

Abstract

In this work, we developed two equivalent-circuit models for both back-to-back and optically addressed dual-band two-terminal photodetector architectures to investigate the impact of luminescence coupling on device performance. The equivalent circuits were constructed using a two-equivalent-diode method. Simulations were conducted using consistent parameters for both architectures to isolate luminescence coupling effects and enable direct comparison. Results show that luminescence coupling is present in both architectures but is significantly enhanced in the optically addressed architecture, leading to a reduction in the specific detectivity and signal-to-noise ratio compared to the back-to-back architecture. Notably, the two architectures exhibit distinct behavior: luminescence coupling increases with signal intensity in the back-to-back design, while it decreases in the optically addressed design. These results highlight the critical role of luminescence coupling in multiband devices and the importance of architecture selection for performance optimization in infrared photodetectors.