Analysis of electrical properties of heterojunction based on ZnIn 2 Se 4

Abstract Heterojunction of n-ZnIn 2 Se 4 /p-Si was fabricated using thermal evaporation of ZnIn 2 Se 4 thin films of thickness 473 nm onto p-Si substrate at room temperature. The characteristics of current–voltage (I-V) for n-ZnIn 2 Se 4 /p-Si heterojunction were investigated at different temperatures ranged from 308 K to 363 K. The junction parameters namely are; rectification ratio (RR), series resistance (R s ), shunt resistance (R sh ) and diode ideality factor ( n ) were calculated from the analysis of I-V curves. The forward current showed two conduction mechanisms operating, which were the thermionic emission and the single trap space charge limited current in low (0 ≤ V ≤ 0.5 V ) and high (V ≥ 0.7 V ) ranges of voltage, respectively. The reverse current was due to the generation through Si rather than the ZnIn 2 Se 4 film. The built-in voltage and the width of the depletion region were determined from the capacitance-voltage (C-V) measurements. The photovoltaic characteristics of the junction were also studied through the (I-V) measurements under illumination of 40 mW/cm 2 . The cell parameters; the short-circuit current, the open-circuit voltage and the fill factor were estimated at room temperature.