Combined Optical and Quantum Simulation of a Resonant Tunneling Diode Photodetector with an Integrated Microlens

In this paper, we present a detailed numerical simulation of a resonant tunneling diode photodetector (RTD-PD) incorporating an In0.53Ga0.47As absorption layer, designed for advanced optoelectronic applications. A microlens structure is integrated on top of the active device to enhance sensitivity and high-speed performance. A two-dimensional (2D) Finite-Difference Time-Domain (FDTD) method is employed to accurately calculate the optical energy absorbed within the active region of the RTD-PD. The Crank–Nicolson scheme is used to solve the time-dependent Schrödinger equation in combination with discrete transparent boundary conditions (DTBCs). Furthermore, the spectral response of the RTD-PD is evaluated, and the resulting spectral sensitivity is compared with that obtained using the ISE-TCAD simulator. Finally, a fully time-dependent Poisson–Schrödinger solver is introduced to simulate the temporal behavior of an RTD-PD oscillator circuit. The results demonstrate that the circuit generates stable high-frequency oscillations, and that the RTD-PD exhibits a highly efficient response to optical illumination.