PHOTOSENSITIVE POLYCRYSTALLINE FILMS OF COMPENSATED LEAD-TELLURIDE PBTE-CL,TE-EX

Photosensitive polycrystalline films of PbTe doped with Cl and an exce ss of Te have been studied. The films were grown by vacuum deposition in a modified quasiclosed volume from compensated starting material. T he composition of the starting material was chosen in a range in which the carrier density depends only negligibly on the concentrations of the dopant and the excess tellurium. Uniform polycrystalline films wit h a carrier density of about 3X10(17) cm(-3), a dark resistance of abo ut 10(6) Omega/square, and a photosensitivity in the range 1-6 mu m, w ithout a high-temperature annealing in air, were produced as a result. The optimum annealing temperature does not exceed 250-270 degrees C. At this annealing temperature, barriers for the current grow to a maxi mum height similar or equal to 50 meV. Such films can be used as the s ensitive elements of solid-state matrix IR detectors. Photoresistive m atrix IR detectors on a Si-SiO2 substrate with 32 X 32 elements and an element size of 50 X 50 mu m(2) have been fabricated. (C) 1994 Americ an Institute of Physics.