The influence of different angles of grating on the performance of quantum well infrared photodetectors

Abstract

Quantum well infrared photodetectors (QWIPs) have natural advantages, such as high material maturity and good uniformity. But its low quantum efficiency is often criticized as a drawback. The quantum well optical coupling structure is one of the key factors affecting the quantum efficiency of quantum well detectors. This article mainly focuses on the impact of the optical coupling structure of quantum well detectors on detector wavelength, coupling efficiency, and other aspects. We have established an optical coupling structure model for quantum well detectors, mainly consisting of three different angles of structure structures: 45 degrees, 62 degrees, and 90 degrees periodic two-dimensional diffraction gratings. The 3D-FDTD simulation method was used to simulate the optical coupling structure of quantum well detectors, and the performance indicators of the three structures, such as response wavelength and coupling efficiency, were compared. At the same time, simulations were conducted on different angles of periodic two-dimensional diffraction gratings. It can be seen that as the grating angle increases, the response spectrum width widens, but the amplitude of the response decreases.