Investigation of Electrical Properties of GaSe:Ge/Te and GaSe:Ge/Ag Schottky Junctions

In this paper, we have investigated electrical properties of germanium doped Gallium Selenide (GaSe) single crystals. Germanium doped GaSe single crystals were grown by conventional Bridgman method. Shchottky junctions were obtained by melting Te or Ag elements on the GaSe:Ge surface. In contacts have been made for the electrical measurements. Characteristic properties of Schottky junctions were investigated as functions of temperature and electric field. It was observed that the ratio of forward bias and reverse bias currents in the Schottky junctions varied with both applied electric field and light excitations. Schottky junctions showed asymmetric current-voltage (I-V) characteristics. The light sensitivity of In/GaSe:Ge/Ag/In Schottky junction was found to be higher than that of In/GaSe:Ge/Te/In Schottky junction. The barrier heights of In/GaSe:Ge/Te/In and In/GaSe:Ge/Ag/In Schottky junctions were calculated as 52.92 meV and 41.82 meV, respevtively. Barrier heights of both Schottky junctions decreased with applied electric field. It was found that barrier heights of the Schottky junctions decreased with the square root of the applied electric field as while the current increased exponentially with the square root of the applied electric field as . These results are consistent with the Frenkel thermoelectric field theory