Tunable infrared detector with narrow bandwidth

US4144540A · kind A · utility

Assignee

• United States of America as represented by the Secretary of the Air Force · US

Inventor

• Nicholas Bottka · Caracas, VE

Key dates

• Filing date: Feb 6, 1978
• Grant date: Mar 13, 1979
• Expiry date: Feb 6, 1998

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10F77/306

Abstract

An infrared detector with narrow band tunable response. The detector is cosed of four layers of epitaxially grown material that is doped for selective wavelength absorption. The uppermost layer has a thickness much larger than the penetration depth of short wavelength radiation or the diffusion length of photo generated carriers near the surface. The upper layer is a heavily N-doped layer over a P-doped layer. The cut-on wavelength edge is determined by the amount of doping in the uppermost layer. By applying a reverse bias to this N-P junction, the cut-off absorption edge can be shifted to longer wavelengths.