Photovoltaic, Capacitance-Voltage, Conductance-Voltage, and Electrical Impedance Characteristics of p-Type Silicon/Intrinsic-Silicon/n-Type Semiconducting Iron Disilicide Heterostructures Built via Facing Target Direct-Current Sputtering

Abstract p-Type Silicon (Si)/intrinsic Si/n-type semiconducting iron disilicide heterostructures were built via facing-target direct-current sputtering. To assess the photovoltaic properties, the current-voltage characteristic curves were recorded in conditions of dark and under irradiation via an Air Mass 1.5 solar simulator (100 mW/cm2). The built heterostructures demonstrated effective rectifying behavior along with a rather substantial leakage current. The open-circuit voltage and the short-circuit photocurrent density values were 178.00 mV and 10.08 mA/cm2, respectively. The assessed energy conversion efficiency was approximately 0.75%. The series resistance (Rs) values at 0 V appraised by the Nicollian-Brews technique were 60.28 Ω at 2 MHz, and 4.13 × 103 Ω at 10 kHz. Their interface state density values evaluated through the Hill-Coleman method were 1.38 × 1012 cm−2/eV at 10 kHz and 1.31 × 1011 cm−2/eV at 2 MHz. The Rs and interface states occurring in the heterostructure interface zone should be the potential determinant of the degeneration of the photovoltaic properties. The characteristics of the real (Z’) and imaginary components of impedance under the changing voltages manifested a shape of one semicircle having a semicircular midpoint beneath the Z’ coordinate. An equivalent circuit model that was related with the heterostructure behavior should be assembled from the parallel association of resistance and constant phase element connected with Rs.