Properties Of P-type ZnO Films Research Articles

The influence of substrate and annealing temperatures on electrical properties of p-type ZnO films

Abstract In this study, p-type ZnO films with excellent electrical properties were prepared by ultrasonic spray pyrolysis (USP) combining with a N–Al codoping technique. The influence of the substrate temperature and annealing temperature on electrical properties of ZnO films was investigated. The growth and doping process of ZnO films was explored by thermogravimetry, differential scanning calorimetry and mass spectrum (TG–DSC–MS) measurements. It is suggested that the variation of electrical properties of ZnO films with the substrate temperature and annealing temperature results from the removal of H element out of the films.

The influence of post-growth annealing on optical and electrical properties of p-type ZnO films

In this study, p-type ZnO films with excellent electrical properties were prepared by ultrasonic spray pyrolysis (USP) combined with a N–Al co-doping technique. The influence of post-growth annealing conditions, i.e., annealing ambient and temperature, on optical and electrical properties of p-type ZnO films was investigated. The dependence of the intensity of the green emission on the annealing ambient indicates that the green emission might originate from the donor defect, oxygen vacancy. The effect of the annealing temperature on electrical properties of ZnO-based films affirms the prominent action of hydrogen in the conductivity and acceptor doping of ZnO films.

Effect of substrates on the properties of p-type ZnO films

Influence of substrates on the properties of p-type ZnO films, which were fabricated by N–Al co-doping technique, was studied. Hall measurement results indicated that ZnO films deposited on common glass substrate were p-type conductivity when Zn:N:Al atomic ratio amounts to 1:3:0.1. However, ZnO films deposited on corning 7059 glass substrate showed n-type conductivity. Secondary ion mass spectroscopy demonstrated that Na content incorporated into ZnO films deposited on common glass substrate was more evident than that of corning 7059 glass. In addition, Hall mobility and conductivity of p-type ZnO thin films deposited on silicon substrate were improved largely.

Structural and electrical properties of p-type ZnO films prepared by Ultrasonic Spray Pyrolysis

Effects of atomic ratio of Zn:N:Al and solution concentration on the structural and electrical characteristic of ZnO films deposited by Ultrasonic Spray Pyrolysis using N–Al co-doping technique were investigated. Hall measurement indicated that with increasing Al doping, conductive type of ZnO thin films changed from n-type to p-type and then to n-type again. However, the solution concentration almost has no effect on the structural and electrical properties of p-type ZnO films. X-ray Photoelectron Spectroscopy indicated that the presence of Al indeed facilitates the incorporation of N through the formation of N–Al bonds in co-doped ZnO films. In addition, Photoluminescence spectra showed p-type ZnO films with a low density of native defects.

Realization of p-type ZnO films via monodoping of Li acceptor

p-Type ZnO thin films have been realized via monodoping of Li acceptor by adopting DC reactive magnetron sputtering. The lowest room-temperature resistivity was found to be 17.6Ωcm with a Hall mobility of 3.47cm2V–1s–1 and carrier concentration of 1.01×1017cm−3 for Li-doped p-type ZnO film deposited on glass substrate. The Li-doped ZnO film possessed a good crystallinity with c-axis orientation and a high transmittance (90%) in the visible region. Moreover, the effects of Li content on the crystallinity, electrical and optical properties of p-type ZnO films were discussed.