Synthesis, characterization, and electrical properties of CuInGaSe2/SiO2/n-Si structure

The current work presents a novel structure of epitaxially grown CuInGaSe2/SiO2 on n-Si substrate using the liquid phase epitaxy (LPE) technique. The electrical and dielectric properties of quaternary alloy CuInGaSe2/SiO2/n-Si were investigated as a Schottky barrier device. The effect of temperature, voltage, and frequency on the electric and dielectric parameters such as dielectric constant e ', dielectric loss e '', dielectric loss tangent tan delta, the real and imaginary part of modulus M ', M '', ac conductivity sigma ac and series resistance Rs were studied by measuring the capacitance-voltage within the temperature range of (303-393 K) and DC voltage range (+/- 5 V). Both capacitance and conductance were highly affected by varying voltage, frequency, and temperature. Remarkably, capacitance has positive values at high frequencies while it takes negative values at low frequencies. The negative capacitance (NC) was observed for all temperatures. The thickness of the oxide layer was 84 x 10(-9) nm. The density of states Nss, Ideality factor, series resistance, shunt resistance, and barrier height were assessed. The impedance spectrum investigation was tailored by suitable equal circuits comprising the contributions of grain and grain boundaries in the conduction mechanism.