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 T 0 =77÷350 K. The dependences of the photo-e.m.f. ( U ph ) value have been measured in the absence of ( U p h 0 ) and under the condition of heating the current carriers ( U p h E ^ ) , as well as the value of Δ U p h = ( U p h E ^ -U p h 0 ) from the wavelength (λ) and light intensity (I), heating electric field strength (Ê), time (τ), temperature ( T 0 ), 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 T 0 , ρD0 , I . The value of U p h E ^ significantly exceeds the value of U p h 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.