Experimental photocurrent-voltage characteristics of higher manganese silicide (HMS)-Si Mn -HMS and HMS-Si Mn -M structures have been analysed. The mechanism is considered of current flow under illumination with hν ≤ E g radiation. In the structures under study, the space-charge-limited-current (SCLC) mode is realized in the temperature interval 77-270 K, and photocurrent-voltage characteristics show regions of linear and quadratic dependence and a region of steep current rise. The high photosensitivity of these structures and the occurrence of SCLC is explained by (i) formation, in the subsurface region of Si diffusion-doped with manganese, of a contact layer of HSM injecting holes into silicon; and (ii) the fact that at low temperature the high-resistance base region of the structures illuminated with intrinsic radiation becomes a low-resistance conducting layer, and a transition layer in which the SCLC mode is realized is formed at the HMS-Si Mn phase boundary.

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Photoelectric properties of (HMS)-Si Mn -M structures, where HMS is higher manganese silicide formed in diffusion doping of silicon with manganese and M is metal contact, have been studied in a wide range of temperatures and light wavelengths.After illumination of these structures with hν = 1.12 eV light at T = 77 K is terminated, the photocurrent decays back to the dark current in a complicated manner, following a curve with two regions. The duration of decay is about several seconds and more than 10 5 s in the first and second regions, respectively.Deep infrared (IR) and temperature quenching of photoconductivity in these structures have been studied.Under illumination with hν 1.12 eV light and at low temperatures these structures can be considered HMS-i-p-M structures, with the i-region playing essential role in the generation of space-charge-limited currents (SCLC).Breakdown of the SCLC mode in these structures by ionization of manganese levels with extra IR light (hν = 0.42−0.6 eV) or by heating results in a sharp decrease of the photocurrent flowing through the structures (especially in the case of temperature quenching in a narrow temperature range T = 15−20 K).

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