Composite CuFe1-xSnxO2/p-type silicon photodiodes

Abstract

CuFe_1-xSn_xO₂ composite thin film/p-type silicon diodes were prepared on substrate by sol-gel method (x=0.00, 0.01, 0.03, 0.05, 0.07). The structure of CuFe_1-xSn_xO₂ composite thin films was studied using XRD analysis and films exhibited amorphous behavior. The elemental compositions and surface morphology of the films were characterized using SEM and EDX. EDX results confirmed the presence of the compositional elements. The optical band gap of CuFe_1-xSn_xO₂ composite thin films was determined using the optic spectra. The optical band gaps of the CuFe_1-xSn_xO₂ composite thin films were calculated using optical data and were found to be 3.75, 3.78, 3.80, 3.85 and 3.83eV for x=0.00, 0.01, 0.03, 0.05 and 0.07, respectively. The photoresponse and electrical properties of the Al/CuFe_1-xSn_xO₂/p-Si/Al diode were studied. The barrier height and ideality factor were determined to be averagely 0.67eV and 2.6, respectively. The electrical and photoresponse characteristics of the diodes have been investigated under dark and solar light illuminations, respectively. The interface states were used to explain the results obtained in present study. CuFe_1-xSn_xO₂ photodiodes exhibited a high photoresponsivity to be used in optoelectronic applications.

Keywords: Composites; Heterojunction; Light-sensing.