Mid-Infrared GaN/AlGaN Quantum Cascade Detector Grown on Silicon

We demonstrate the first implementation of a GaN-based infrared photodetector epitaxially grown on silicon. The device is a GaN/AlGaN quantum cascade detector that consists of layered quantum well structure grown by plasma-assisted molecular beam epitaxy on a 4-in Si (111) substrate. The design, simulations, growth process, optical measurements and device performance are presented and discussed. The photosignal, centered at a wavelength of 4.4
$\mu \text{m}$
, is resolved up to 150 K. The zero bias responsivity is
$44~\mu \text{A}$
/W at 19 K and the detectivity is
$2\times 10^{8}$
Jones.