Photo-e.m.f. at a metal/layered n-InSe semiconductor contact under heating conditions of current carriers by an electric field

The features of the photo-e.m.f. are experimentally studied on the metal/n-InSe contact under conditions of heating the current carriers by an electric field in the temperature range of T₀ =77÷350 K. The dependences of the photo-e.m.f. (U_ph) value have been measured in the absence of $({U}_{ph}^{0})$ and under the condition of heating the current carriers $({U}_{ph}^{\hat{E}})$, as well as the value of $\Delta {U}_{ph}=({U}_{ph}^{\hat{E}}{\text{-U}}_{ph}^{0})$ from the wavelength (λ) and light intensity (I), heating electric field strength (Ê), time (τ), temperature (T₀), the initial value of the dark resistivity (ρD0 at 77K) n-InSe. It has been established that the heating of current carriers by an electric field significantly affects the magnitude and behavior of the photo-e.m.f. characteristics on the metal/n-InSe contact. The nature of this effect depends on T₀,_ρD0, I. The value of ${U}_{ph}^{\hat{E}}$ significantly exceeds the value of ${U}_{ph}^{0}$. With an increase in Ê, the value of AUph increases linearly (ΔU_ph~Ê) at relatively small Ê, and the dependence of ΔU_ph(Ê) reaches saturation at higher Ê. The value of ΔU_ph decreases with increasing _ρD0, at relatively small Ê. With an increase in _ρD0, the relaxation time of the photo-e.m.f. also increases when turned off the pulse of the electric field. The obtained experimental results are explained on the basis of the dependence of the photo-e.m.f. on the metal/n-InSe contact on the effective temperature of heated current carriers (T_e), considering the effect of the spatial inhomogeneity of n-InSe crystals on the photo-e.m.f. and on the process of heating the current carriers.