Group II-VI radiation detector for simultaneous visible and IR detection

US5567975A · kind A · utility

Assignee

• Santa Barbara Research Center · US

Inventors

• Devin T. Walsh · Goleta, US
• Michael Ray · Southfield, US

Key dates

• Filing date: Jun 30, 1994
• Grant date: Oct 22, 1996
• Expiry date: Jun 30, 2014

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10F39/1843

Abstract

A photovoltaic diode unit cell (10) includes a first layer (14) having a first type of electrical conductivity and a second layer (16) of Group II-VI material having a second type of electrical conductivity that differs from the first type. The first layer and the second layer are coupled together so as to form a photovoltaic junction (15) therebetween. The photovoltaic junction is coupled via electrical interconnects (18, 20, 22) to a readout 24 and collects first charge carriers resulting from an absorption of IR radiation within the layer 14. The junction also collects second charge carriers resulting from the absorption of visible light in a region of highly graded crystal potential formed, in a Liquid Phase Epitaxy (LPE)-grown embodiment of this invention, at an interface of a substrate and the first layer. The substrate is subsequently removed, preferably by a mechanical operation followed by a wet chemical etch, to expose the region of highly graded crystal potential.