Photoconduction amplification and quenching in the Mn$_4$Si$_7$–Si$\langle$Mn$\rangle$–Mn$_4$Si$_7$ and Mn$_4$Si$_7$–Si$\langle$Mn$\rangle$–M heterostructures

The photoconduction amplification and quenching in the Mn$_4$Si$_7$–Si$\langle$Mn$\rangle$–Mn$_4$Si$_7$ and Mn$_4$Si$_7$–Si$\langle$Mn$\rangle$–M heterostructures are studied. It is shown that, at low temperatures, the high-ohmic base region of the HMS-Si$\langle$Mn$\rangle$-HMS or HMS-Si$\langle$Mn$\rangle$-M structures irradiated by intrinsic light becomes a low-ohmic conducting layer in the transition $i$-type region of the structures. The mechanism of amplification of the photoconduction in the heterostructures that is caused by collisional ionization in the $i$-type region is revealed. The sharp quenching of the photoconduction in the temperature range 180–220 K is explained.