DICHROMATIC PHOTODETECTOR WITH ELECTRONIC SWITCHING OVER OF RANGES Russian patent published in 1996 - IPC

FIELD: semiconductor equipment. SUBSTANCE: width of forbidden zone of photosensitive material in direction from illuminated surface Z starts to change at distance corresponding to depth of absorption of 50-80% of Z_o radiation from width of forbidden zone applicable to short-wave range E_g1 of operation of photodetector, to width of forbidden zone corresponding to long-wave range E_g2. Gradient of width of forbidden zone in this case meets condition -2E_g1/w₂•(1-(Z-Z_o)/w₂≅ ▿E_g(Z)≅ 0 with Z_o≅ Z Z_o+w₁ and measurement amplitude of width of forbidden zone satisfies condition where ε₁, ε₂ and w₁, w₂ are dielectric constants and width of barriers in semiconductors having E_g1 and E_g2 correspondingly. Electrodes of image recording are manufactured from material which lets pass 50-80% of radiation and electrodes of collection and transfer shield photosensitive material from radiation. Collection and transfer electrodes may be shielded from radiation. Collection and transfer electrodes may be shielded from radiation by opaque screen. Photodiodes on the basis of Schottky barrier or p-n junction may be made in vary-zone plate provided that width of region of volumetric charge exceeds values Z_o. Photosensitive plate can be fabricated in the form of epitaxial structure. EFFECT: elimination of signal self-elimination, simplification of design of photodetector and increase of its detective capability. 5 cl, 9 dwg