Photoinduced effects in $\alpha Si:H$ films at elevated temperatures

The kinetics of dark conduction $(\sigma_d)$ in high-resistance $\alpha Si:H$ films during and after illumination at elevated temperatures (T > 120°C ) has been studied. It has been established that the $\sigma_d(t)$ value changes nonmonotonically: during illumination, it first decreases and then increases; after illumination, it first increases to a value larger than the equilibrium one and then slowly decreases to the equilibrium value. It has been shown that the time dependences of $\sigma_d(t)$ relaxation can be described by the sum of two extended exponents with different parameters $\tau$ and $\beta$. The nature of nonmonotone changes in $\sigma_d(t)$ is discussed.