Dynamical properties and performances of ß-Ga2O3 UVC photodetectors of extreme solar blindness
Abstract
There is a surge in interest for the ultra wide bandgap (Eg ~ 4.9 eV) semiconductor gallium oxide (Ga2O3). A key driver for this boom is that single crystal wide area bulk β-Ga2O3 substrates have become commercially available and that a variety of methods have been shown to give high quality epitaxial growth. Amongst a whole range of potential applications (power/switching electronics, solar transparent electrodes, etc.) extreme solar blindness photodetectors in β- Ga2O3, the more stable monoclinic phase of Ga2O3, offers the most exciting perspectives for deep ultraviolet observations below 250 nm. We present an overview of the complete realization process (epitaxy, photolithography, singulation and packaging), and space qualification (to TRL8) of a series of β-Ga2O3 photodetectors We insist on their remarkable solar blindness performance (factor 1000 or more between peak responsivity around 215-220 nm and 250 nm) and dynamical properties (rise and fall times < 5 ms), along with their enhanced responsivity, excellent thermal behaviour and radiation hard properties. 4 of these detectors have been integrated on the INSPIRE-SAT 7 nanosatellite expected to be launched in April 2023 to reach the TRL9 "demonstrated in flight" qualification.