Fabrication and characterization of Au/n-ZnO/p-Si/Al sandwich device with Sol–gel spin coating method

Abstract

ZnO thin films with the n-type properties were obtained on the p-Si substrates for multi-layered sandwich device depositing by sol–gel method. Au and Al were conducted on two side of hetero-junction by PVD technique. From X-ray diffraction pattern, a strong (002) direction is observed, which means the film is hexagonal texture. Cross-section image from the scanning electron microscope demonstrated that the coated ZnO films had ~ 427 nm thickness. Electrical behavior of the device was characterized by applying voltage versus current. High purity Au and Al metals were vacuum evaporated to make Schottky and Ohmic contacts onto the device. Au/n-ZnO/p-Si/Al architecture exhibited a rectification behavior. According to Thermionic emission mechanism theory, barrier height and ideality factor of device were found as 1.4 and 0.54 eV, respectively. The series resistance values were obtained from dV/d(lnI) versus I and H(I) versus I graphs as 43.6 Ω and 229.9 Ω, respectively.