The novel transparent sputtered p-type CuO thin films and Ag/p-CuO/n-Si Schottky diode applications

In the current paper, the physical properties and microelectronic parameters of direct current (DC) sputtered p-type CuO film and diode have been investigated. The film of CuO as oxide and p-type semiconductor is grown onto glass and n-Si substrates by reactive DC sputtering at 250 °C. After deposition, a post-annealing procedure is applied at various temperatures in ambient. Through this research, several parameters are determined such structural, optical and electrical magnitudes. The thickness of CuO thin films goes from 122 to 254 nm. A (1 1 1)-oriented cubic crystal structure is revealed by X-ray analysis. The grain size is roughly depending on the post-annealing temperature, it increases with temperature within the 144–285 nm range. The transmittance reaches 80% simultaneously in visible and infrared bands. The optical band gap is varied between 1.99 and 2.52 eV as a result of annealing temperature while the resistivity and the charge carrier mobility decrease with an increase in temperature from 135 to 14 Ω cm and 0.92 to 0.06 cm2/Vs, respectively. The surface of samples is homogenous, bright dots are visible when temperature reaches the highest value. As a diode, Ag/CuO/n-Si exhibits a non-ideal behavior and the ideality factor is about 3.5. By Norde method, the barrier height and the series resistance are extracted and found to be 0.96 V and 86.6 Ω respectively.

Graphical abstractA cross section schematic of the Ag/CuO/Si/Au structure.Figure optionsDownload full-size imageDownload as PowerPoint slide