Research On Growth And Stability Of P-type In-N Codoped Zn O Film

Zn O, with a direct band gap of 3.37 e V and a large exciton binding energy of 60 me V at room temperature(RT), is regarded as a promising material for light emitting diodes(LED) and UV lasers in the ultraviolet to blue spectral range.Unintentional Zn O is the n-type conductive semiconductor due to its residual defects. However, it is difficult to obtain stable and reproducible p-type Zn O films. Many researchers has been successfully achieve the p-type Zn O film with different preparation and doping technology. Among them, the donor-acceptor codoping is an effective means which can improve the concentration of acceptor and reduce the acceptor level. However, there is still exist a problem that properties of p-type Zn O films is unstable by the donor-acceptor codoping. which is the bottleneck of restricting the Zn O in the field of photoelectric large-scale application. In order to explore the reasons for the unsteady p-type Zn O conductivity, many research groups realize donor-acceptor codoping by two steps, their research provide a positive way for donor defect of research in stages and effective regulation.Based on the codoping theory, in the present work, the Zn O:In films were grown on quartz substrates by RF magnetron sputtering. Combined with X-ray diffraction(XRD), atomic force microscope(AFM) Raman spectra, and Hall measurements, the effect of post-annealing on the intrinsic defects of simple system with single donor doped is investigated. Through the analysis of Zn O:In film surface morphology, raman spectra and the change of electrical properties with the different annealing temperature. It is found that the origin of the 274 cm-1 mode is attributed to Zn interstitial(Zni) defects, then through the direct implantation of N+ ions obtained Zn O:In:N film. When the Zn O:In:N films were annealed in high purity Ar(99.999 %) 20 min, the post-annealing temperature is 720 °C, p-type Zn O:In:N films can be obtained. However, p-type Zn O:In:N films are unstable, the main reason is that Ni still exist in the p-type Zn O:In:N films. We propose the secondary annealing treatment method that the p-type Zn O:In:N films were annealed in high vacuum 10 min, the post-annealing temperature is 600 °C, the stability of p-type Zn O:In:N films are well improved.