Fabrication and Electrical Characterization of the Si/ZnO/ZnO:Al Structure Deposited by RF-Magnetron Sputtering

The electrical transport properties of the structures of Si(p)/ZnO(i)/ZnO: Al(3%) and Si(p)/PS/ZnO(i)/ZnO: Al(3%) deposited by radio-frequency-magnetron sputtering were investigated and compared by using current–voltage and impedance spectroscopy measurements in a wide temperature range of 80–300 K. Aluminum-doped ZnO is considered to be one of the most important transparent conducting oxide materials due to its high conductivity, good transparency and low cost. From the current–voltage–temperature (I–V–T) characteristics, it was found that both structures had a good rectifying behavior. This behavior decreases according to the porous silicon layer. The variation of the conductance with frequency indicates the semiconducting behavior and superposition of different conduction mechanisms. The insertion of the porous silicon layer results in a decrease of conductivity, which is attributed to reduced conductivity of defect-rich porous silicon.