SEMICONDUCTOR AVALANCHE PHOTODETECTOR WITH VACUUM OR GASEOUS GAP ELECTRON ACCELERATION REGION

摘要

A semiconductor avalanche photodiode (APD) with very high current gain utilizes a small vacuum or gas filled gap, which is used as a region to accelerate electrons to high energies. The APD has an absorption layer, a gap, and a multiplication layer. The absorption layer is adapted to generate electron-hole pairs upon absorbing light. The APD is adapted to generate an electric field in the gap and at an interface between the absorption layer and the gap. The electric field extracts electrons from the absorption layer into the gap and accelerates the extracted electrons while in the gap. The multiplication layer is adapted so that said accelerated electrons impinge on and cause a flow of secondary electrons within the multiplication layer.