Tunable internal photoemission sensor using silicide/silicon heterostructures

A new silicide/silicon IR detector is presented which has the potential for multicolor detection due to the tunability of its photoresponse and cutoff wavelength. This tunable internal photoemission sensor (TIPS) consists of two back-to-back Schottky diodes separated by a thin undoped Si layer. The two metals are chosen with different Schottky barrier heights so that the depleted Si forms an asymmetrical potential barrier to the carriers (both holes and electrons) photocreated in each metallic film. Under sub-band gap illumination the photocurrent flowing between the two metallic films is therefore strongly dependent on the shape and height of the potential barrier which can be varied by a small bias applied between the two metal electrodes.<>