Photocapacitance effect in narrow band gap PbSnTe

摘要

Low frequency permittivity of PbSnTe solid solution was investigated in darkness and under illumination. ε=2,000-300,000 was found depending on temperature and illumination. For the first time the increase of ε under illumination by about two orders was observed at LH temperature. Far IR cut off of the effect was estimated. It was found that the best correlation of calculations with experimental data took place if we supposed the presence of narrow band of PbSnTe sensitivity within 300 - 400 μm spectral region.