Papers by Author: Cheng Jun Zhu

Abstract: Thin films of RE_0.5Sr_0.5CoO_3-δ (RE=La, Pr, Nd) nominal composition were grown on yttria-stabilized zirconia (YSZ) single crystal substrates by ion-beam sputtering deposition method. The X-ray diffraction spectra and X-ray photoelectron spectroscopy were measured for RE_0.5Sr_0.5CoO_3-δ thin films with perovskite structure. The experimental results indicate that the average grain size of RE_0.5Sr_0.5CoO_3-δ thin films ranges from 86 to 165 nm，and the film obtained by heat-treating at 750 °C is highly oriented . The RE_0.5Sr_0.5CoO_3-δ thin films being mixed-valent systems contains Co³⁺ and Co⁴⁺ ions. There is oxygen vacancy at an interface region for RE_0.5Sr_0.5CoO_3-δ thin films.

Abstract: Cu(In_0.8Al_0.2)(SSe)₂ (CIASSe) absorber layers of thin film solar cell were prepared by selenization of Cu(In_0.8Al_0.2)S₂(CIAS) nanocrystals. The CIAS nanocrystals were synthesized by a new solution-based technique and successfully deposited on Mo-coated glass substrates in a one-step process. The phase structure, optical and electrical properties of CIASSe thin films were characterized by power X-ray diffraction (XRD), ultraviolet-visible (UV-Vis) spectrophotometer and the Hall Effect Measurement system. The results showed that single-phase CIASSe solid solution was successfully obtained for a selenization temperature of above 400oC. And the diffraction peaks shifted to the lower angle with an increase in selenization time and selenization temperature. The films selenized at 500oC were found to be p-type and the resistivity was only 0.9484×10^-4Ω cm. The optical band gap of the films is 1.508eV and the optical absorption coefficient is over 10⁴cm^-1.