Patent ID: 8592863

Claim:
A photodetector with internal gain comprising: a semiconductor layer having a thickness and formed along a main plane and made of a P-type Cd x Hg 1-x Te alloy having a stoichiometric Cd composition of less than 60% so that impact ionization events are produced only by minority charge carriers in the semiconductor layer; a first biasing contact and a second biasing contact that both penetrate and are located in the semiconductor layer, wherein the first and second biasing contacts extend along parallel planes that are perpendicular to the main plane of the semiconductor layer and are separated along the main plane of the semiconductor layer; a photon collection region formed in the thickness of the semiconductor layer adjacent to the first biasing contact; a P-N junction formed in the semiconductor layer adjacent to the second biasing contact, wherein the photon collection region and the P-N junction are respectively located along said parallel planes of the first and second biasing contacts in the semiconductor layer and are separated by a distance alone the main plane of the the semiconductor layer; and a collector contact which is located in the P-N junction and used to collect current in the P-N junction.