This work demonstrates a mid-wavelength infrared InAs/InSb superlattice avalanche photodiode (APD). The superlattice APD structure was grown by molecular beam epitaxy on GaSb substrate. The device exhibits a 100 % cut-off wavelength of 4.6 µm at 150 K and 4.30 µm at 77 K. At 150 and 77 K, the device responsivity reaches peak values of 2.49 and 2.32 A/W at 3.75 µm under −1.0 V applied bias, respectively. The device reveals an electron dominated avalanching mechanism with a gain value of 6 at 150 K and 7.4 at 77 K which was observed under −6.5 V bias voltage. The gain value was measured at different temperatures and different diode sizes. The electron and hole impact ionization coefficients were calculated and compared to give a better prospect of the performance of the device.
AbstractThe thin-film In_ x Al_ y Ga_1 – x – y As_ z Sb_1 – z /GaSb heterostructures have been grown from liquid phase in a temperature gradient. The growth kinetics, the composition, the structural perfection, and the luminescence properties of the InAlGaAsSb thin films grown on a GaSb substrate have been studied.
Avalanche Photodetector Based on InAs/InSb Superlattice
