Electrochemical Fabrication and Characterization of p-CuSCn/n-ZnO Heterojunction Devices

Autores UPV


p-CuSCN/n-ZnO heterojunction devices were prepared by depositing CuSCN electrochemically over a ZnO film previously deposited. The compact and smooth surface films of n-ZnO on FTO substrate were deposited electrochemically from a nonaqueous bath. The CuSCN films were characterized by cyclic voltammetry, chronoamperometry, SEM, energy-dispersive X-ray spectroscopy, and XRD measurements. The pure crystalline films of CuSCN with intrinsic trigonal pyramidal morphology over the ZnO films were obtained electrochemically by fixing the SCN/Cu ratio in the electrolytic bath 1.5:1 at 60 °C with −0.4 V deposition potential. Photocurrent measurements showed the increase of intrinsic surface states or defects in ZnO/CuSCN interface. The I¿V characteristic of p-CuSCN/n-ZnO heterojunctions shows good rectification behavior with a rectification ratio of 250 at ±2 V. The value of 2.81 of the ideality factor calculated by fitting the semilogarithmic I¿V data with the ideal diode equation revealed the better electrical contact between the smooth ZnO and CuSCN films than that of ZnO nano-rods and CuSCN crystallites.