Application of ZnO and poly-Si in thin-film heterostructures

Abstract

In this work, thin-film heterojunction is prepared using ZnO and poly-Si thin films and its I–V characteristics are presented. ZnO thin films have been applied for device engineering in different heterostructures, as well. In this work, the I–V characteristics of a thin-film heterostructure n-ZnO/poly-Si are studied. The ZnO polycrystalline films are deposited by RF sputtering in an atmosphere of Ar on the surface of a p-type poly-Si layer. The poly-Si films are prepared on glass substrate by the method of aluminum-induced crystallization (AIC) from precursor layers of Al and a-Si:H. The Al and a-Si:H precursor films are deposited by magnetron sputtering on glass substrate. The a-Si:H film precursors contain 9 at% hydrogen. The isothermal annealing of the structure glass/Al/a-Si:H is performed in forming gas (N2 + 5%H2) in the temperature range of 530–550 °C for 7 and 21 h. The properties of the films are studied by X-ray diffraction (XRD), optical microscopy, optical transmission and reflection, and Raman spectroscopy. The I–V characteristics of the thin-films heterostructure n-ZnO/ poly-Si show diode behavior and ideality factor of 2.95.The structure exhibits photosensitivity under illumination.