Cadmium telluride (CdTe) thin films deposited by pulsed laser deposition (PLD) on fluorine–tin–oxide substrates under different pressures of argon (Ar) + oxygen (O2) at high substrate temperature (Ts = 500 °C) was reported in this paper. In our work, the CdTe thin films were prepared successfully at high Ts by inputting Ar + O2. As reported, PLD-CdTe thin films were almost prepared at low substrate temperatures (<300 °C) under vacuum conditions. The deposition of CdTe thin films at high Ts by PLD is rarely reported. The influence of the Ar + O2 gas pressure on thickness, structural performance, surface morphology, optical property and band gap (Eg) had been investigated respectively by Ambios probe level meter, X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV–Vis spectrometer. Strong dependence of properties on the deposition pressures was revealed. In the range of Ar + O2 gas pressure from 5 to 12 Torr, the deposition rate and the Eg of CdTe films vary in the range of 41.9–57.66 nm/min then to 35.26 nm/min and 1.51–1.54 eV then to 1.47 eV, respectively. The XRD diagrams showed that the as-deposited films were polycrystalline, and the main phase was cubic phase. However, the preferred orientation peak disappeared when the deposition pressure was higher. SEM images indicated that the CdTe film deposited at a higher deposition pressure was more uniform and had a higher compactness and a lower pinhole density. Furthermore, based on this thorough study, FTO/PLD-CdS (100 nm)/PLD-CdTe (~1.5 μm)/HgTe:Cu/Ag solar cells with an efficiency of 6.68 % and an area of 0.64 mm2 were prepared successfully.

Pulsed laser deposition (PLD) is one of the promising techniques for depositing cadmium telluride (CdTe) thin films. It has been reported that PLD CdTe thin films were almost deposited at the lower substrate temperatures (<300 degrees C) under vacuum conditions. However, the poor crystallinity of CdTe films prepared in this way renders them not conducive to the preparation of high-efficiency CdTe solar cells. To obtain high-efficiency solar cell devices, better crystallinity and more suitable grain size are needed, which requires the CdTe layer to be deposited by PLD at high substrate temperatures (>400 degrees C). In this paper, CdTe layers were deposited by PLO (KrF, lambda=248 nm, 10 Hz) at different higher substrate temperatures (Ts). Excellent performance of CdTe films was achieved at higher substrate temperatures (400 degrees C, 550 degrees C) under an atmosphere of Ar mixed with O2 (1.2 Torr). X-ray diffraction analysis confirmed the formation of CdTe cubic phase with a strong (1 0 0) preferential orientation at all substrates temperatures on 60 mJ laser energy. The optical properties of CdTe were investigated, and the band gaps of CdTe films were 1.51 eV and 1.49 eV at substrate temperatures of 400 degrees C and 550 degrees C, respectively. Scanning electron microscopy (SEM) showed an average grain size of 0.3-0.6 mu m),m. Thus, under these conditions of the atmosphere of Ar+O2 (15 Torr) and at the relatively high Ts (500 degrees C), an thin-film (FTO/PLD-CdS (100 nm)/PLD-CdTe (similar to 1.5 mu m)/HgTe: Cu/Ag) solar cell with an efficiency of 6.68% was fabricated. (C) 2013 Elsevier B.V. All rights reserved.

The CdS films were deposited by Rf-magnetron sputtering on the 1 mm Na-Ga glass at room temperature.The structural and optical properties of the as-deposited films were investigated by XRD,UV/Vis spectroscopy and stylus profiler.And the effect of sputtering power on the characters of films was studied.The results show that the prepared CdS films was cubic and hexagonal mixed crystal phase.There was highly preferred orientation at(002),(004) of hexagonal crystal phase and(111),(222) of cubic crystal phase.The thickness and the grain are increased when the prepared powers are improved.The absorption edges of films are of red-shifted.The crystalline CdS thin films with 2.36 eV band gap are deposited at room temperature,0.6Pa,30W and pure Ar atmosphere conditions.

This paper focuses on physical properties of ZnS thin films.ZnS thin films were successfully fabricated on Fluorine-Tin-Oxide(FTO) substrates(in a vacuum chamber maintained at 10-6Torr) at the substrate temperatures(Ts) of 150°Cand 200°Cby pulsed laser deposition(PLD),respectively.The structural properties of the ZnS films were analyzed with a X-ray diffraction(XRD) spectroscopy;The surface morphology of ZnS films was examined using scanning electron microscopy(SEM). With the increasing of the substrate temperature,the intensity of the (111) diffraction peak increases clearly and the surface of the ZnS films was more homogeneous and more compact.The main phase of the films deposited at 150°C and 200°C are both cubic-zinc-blende structure.The transmission spectra of the films was measured by UV-Vis spectrophotometer(UV,model a Perkin Elmer-Lambda 950),it shown that the films have the high transmittance in the spectrum of the visible light range,and the optical energy gaps were 3.48eV and 3.54eV,corresponding to the substrate temperatures of 150°C and 200°C.The results shown that the PLD technique can fabricate the better ZnS thin films.

The Zinc sulfide(ZnS) thin films are prepared on glass substrate by RF magnetron sputtering technique at different substrate temperatures and Ar gas flows.Characterization of the film properties is carried out using surface probe surface profilometer,ultra-vision/vision(UV/Vis) spectrophotometer and X-ray diffraction(XRD).The results indicate that X-ray diffraction analysis confirms the formation of ZnS sphalerite phase and has strong(111) preferred orientation and great lattice stress at all substrate temperatures.The deposited rates are reduced with the increasing of the substrate temperature.The best thin film is deposited as the substrate temperature is 300℃.The Ar gas flow has great positive correlation influence on deposited rates,but little influence on the optical and microstructure properties.