On the photoinduced effect in undoped $a$-Si:H films

The temperature dependences of the dark conductivity and photoconductivity of annealed and preliminarily illuminated undoped $a$-Si:H films are studied in different modes of temperature variation. Also, the variation kinetics of the photoconductivity and dark conductivity of the films during and after their exposure to light at different temperatures are analyzed. It is shown that the anomalous nature of the dependences obtained may be due to the formation of two kinds of photoinduced defects that have different energies of formation and thermal annealing and energy levels situated in different parts of the band gap of the films under study.