Device behavior of an In/p-Ag(Ga,In)Te2/n-Si/Ag heterojunction diode

In this work, p-(Ag–Ga–In–Te) polycrystalline thin films were deposited on soda-lime glass and n-type Si substrates by e-beam evaporation of AgGa0.5In0.5Te2 crystalline powder and the thermal evaporation of Ag powder, sequentially in the same chamber. The carrier concentration and mobility of the Ag–Ga–In–Te (AGIT) film were determined as 5.82×1015 cm−3 and 13.81 cm2/(V s) as a result of Hall Effect measurement. The optical analysis indicated that the band gap values of the samples were around 1.58 eV. The structural analysis was carried out by means of X-ray diffraction. Current–Voltage (I–V  ) measurements depending on the sample temperature were performed to investigate the device characteristics and the dominant conduction mechanism in an In/p-AGIT/n-Si/Ag structure. The series and shunt resistances were calculated by the help of parasitic resistance analysis as 5.735.73 and 1.57×1041.57×104 Ω cm2, respectively at room temperature. The ideality factors and barrier heights were evaluated as a function of sample temperature. In the low bias region, the thermionic emission together with the generation–recombination mechanism was investigated as the dominant transport mechanism; however, in the high bias region, space charge limited current was analyzed as the other effective mechanism in the carrier conduction. The built-in potential of the device was also determined by the help of capacitance–voltage measurements.