Results of investigation of In/MnIn2S4 Shottky barriers have been presented in the given work. The indicated barriers were created by vacuum thermal deposition of indium thin films on MnIn2S4 single crystals grown by Bridgman’s method. Silver compound was used as ohmic contact. The crystals obtained reveal n-type of conductivity and resistivity r»109-1010 Ω×cm at 300 K. In the temperature interval 300-450 K the resistivity follows to exponential law:
formula
where k is Bolzsmann’s constant, Ed – donor centers activation energy. Investigation of permanent current-voltage characteristics of In/MnIn2S4 structures have shown, that they reveal rectification, which was characterized by ratio of direct current to inverse one at bias voltage |U| » 10 V. Photovoltaic effect is observed reproducibly at illumination at which the substrate crystal was charged negatively, what corresponds to direction of rectification. Photosensitivity of the best structures has reached » 100 V/W at Т = 300 K, and photovoltage sign does not depend on photons energy and incidence place of light probe on the surface of structures. This circumstance allows to consider that the received spectra of relative quantum efficiency h(ħw) are defined by properties of indium barriers with surfaces MnIn2S4. At illumination of In/MnIn2S4 structures from the side a barrier photosensitivity is shown in a wide spectral range 1.3 – 3.6 eV whereas transition to illumination from the side of crystal leads to that spectrum h(ħw) becomes selective and its maximum hwm » 1.59 eV in process of reduction of a thickness of substrates is displaced in short-wave area. Short-wave photosensitivity fall is connected, apparently, to growth of factor of optical absorption therefore the area of photogeneration of nonequilibrium charge carriers leaves from active area of structure more and more and there is fall of h. The full width of spectra h(ħw) at their half-height in case of illumination of barriers from the side of crystal of MnIn2S4 substrate is d » 0.3 eV at a thickness of substrate » 2 mm appears to be essentially more low, than at illumination of the same structure from the side a barrier. Observable recession of h specifies in fast increase in factor of optical absorption in MnIn2S4 crystal at ħw > 1.6 eV that can be connected with approach of interband transitions. At illumination of In/MnIn2S4 structures from the side of a barrier the full width d of h(ħw) spectra at their half-height strongly increases, and at ħw> 3.0 eV photosensitivity of structures reaches the maximum value and does not find out short-wave recession. This circumstance specifies in high enough quality of created barriers In/MnIn2S4 because of what in the investigated spectral range influence of surface recombination practically was not observed.