Proceedings Article | 15 June 2023
KEYWORDS: Aluminum, Avalanche photodetectors, Aluminum gallium nitride, Deep ultraviolet, Sapphire, Imaging spectroscopy, Electric fields, Doping, Chemical composition, Absorption
Significant efforts have been made on realizing deep ultraviolet (UV) – (200 – 280 nm) detectors; however, target detection elements remain inefficient, bulky, and low sensitivity. An ideal detector, particularly avalanche photodetectors (APDs) for this region must have high gain, high efficiency, and low noise. Ultrawide bandgap (UWB) AlxGa1-xN material system has shown promise to enable the design of high quantum efficient (QE), radiation-hard detectors capable of operating at high temperatures in this region. However, achieving high quality material becomes more difficult at higher Al compositions due to challenges associated with nonuniformity and doping efficiency. Current APDs are unable to provide high QE, low dark current, high multiplication gain, and solar blindness without coatings. We are developing III-Nitrite based APDs for single photon detection to operate filter-free in the deep-UV band. Toward this objective, we present results on development of high quality, high Al composition AlxGa1-xN with high conductivity, and demonstrate first in the world fabricated Separate Absorption and Multiplication (SAM) APD devices with 65% Al composition. Physics-based TCAD simulations utilizing the material system, and device measurement results are also presented. The proposed APD and its array, with single photon detection capability using III-N material systems will have earth science, space, defense, and commercial applications including UV spectroscopy, non-line of sight communications, portable chemical and biological identification systems.
