Bing Ren

Effect of Ar Pressure on Properties of Polycrystalline CdZnTe Films

Polycrystalline CdZnTe (CZT) films were grown by close-spaced sublimation method. The CdZnTe films were prepared on fluorine doped tin oxide (FTO) glass substrates at various argon (Ar) pressures from 200 Pa to 700 Pa. A comparative study of the films at different pressures was obtained by X-ray diffraction (XRD), scanning electron microscope (SEM) and Energy dispersive spectrometer (EDS) respectively. The XRD studies revealed that CdZnTe films had a preferential orientation along the (111) phase except the one at 500 pa. EDS analysis indicated that the increasing of Ar pressure decreased Zn content.

Effects of the Substrate Temperature on the Structure and Properties of Cd1-xMnxTe Films

Cd1-xMnxTe (CdMnTe) can be a good candidate for gamma and X-ray detection because of its wide band-gap, high resistivity, and good electro-transport properties. Polycrystalline CdMnTe films were grown by closed-space sublimation method on glasses at different substrate temperatures. In this paper, substrate temperature dependent surface morphology, chemical composition, structural and electrical properties of CdMnTe films are investigated systematically.

Influences of Working Power on Properties for Boron Films Deposited by R. F. Magnetron Sputtering

Boron and boron-rich boride has attracted considerable attention in the past few years for their wide varieties of structures and property associated with their unusual three-center electron-deficient bonds. Boron film also exhibits many unique and fascinating properties, such as high melting point (~ 2500K) with low density, high harness close to diamond, and excellent thermoelectric property. In this paper, boron (10B) films were prepared on (100) silicon substrate by radio frequency (r. f.) magnetron sputtering method under the different working pressure and power with a target of boron and boron oxide (B:B2O3 40wt%). After 3 hours sputtering deposition, the substrate was covered with boron films tightly. The morphology of deposited films under different temperature was characterized by high resolution scanning electron microscopy (HRSEM), FTIR spectrum (FTIR), Raman spectrum (Raman). The results show that the film contains boron and little oxygen. At last, the growth mechanism of B film was analyzed.

Effects of substrate temperature on morphology, structure and chemical composition of Cu2S films

Cu2S thin films have been deposited on CdS/ITO (In2O3:Sn) substrates with various substrate temperatures by DC magnetron sputtering method. The effects of substrate temperature on the crystallization behavior and morphology are studied. Chemical composition of the films is confirmed by energy dispersive X-ray (EDX) spectroscopy. X-ray diffraction (XRD) analysis of the films reveals they have polycrystalline chalcocite structure with (110) texture. Field emission scanning electron microscopy (FESEM) show the crystalline nature of the films at higher substrate temperature, which is in accordance with XRD measurements. Stoichiometric analysis exhibits element composition with Cu/S concentrations ratio equal to 2 approximately.

Growth of Highly (110) Oriented Diamond Film by Microwave Plasma Chemical Vapor Deposition

In this study, we propose a simple and effective approach to enhance (110) orientation in diamond films grown on (100) Si substrates by microwave plasma chemical vapor deposition. It is found that the crystalline structure of diamond films strongly rely on the CH4 concentration in the nucleation stage. Under the same growth condition, when the CH4 concentration is less than 7% (7%) in the nucleation stage, the diamond films exhibit randomly oriented structure; once the value exceeds 7%, the deposited films are strongly (110) oriented. It could be verified by experiments that the formation of (110) orientation in diamond films are related to the high nucleation density and high fraction of diamond-like carbon existing in nucleation samples.

Asymmetric resistive switching behaviour in a Au/a-C:Co/Au planar structure

Abstract Using a simple fields induced mass motion method, Au/a-C:Co/Au planar structures with micro-gap Au electrodes were fabricated. Asymmetric current-voltage characteristics and resistive switching behaviours were observed in these cells. Reliable performance, with a reasonable ON/OFF ratio of >4, stable endurance of >200 cycles, and good retention of >105 s, were achieved at the read voltage of −3.6 V. Space charge limited current (SCLC) theory with an asymmetric potential barrier caused by different densities of traps was proposed to explain the asymmetric resistive switching behaviour.

Growth of AlN Films on Silicon Substrates by Radio Frequency Magnetron Sputtering

Polycrystalline aluminum nitride (AlN) films were deposited on Si (111) substrates by radio frequency (RF) magnetron sputtering method in an nitrogen (N2) + argon (Ar) gas mixture. The effect of the preparation conditions- sputtering pressure (p), sputtering power (w), gas mixture (Ar/N2) and post-deposition annealing treatment -on the properties of AlN films were investigated by means of X-ray diffraction (XRD). Highly c-axis oriented AlN films were obtained with optimized growth parameters: p=0.3Pa, w=400w and Ar/N2=2.

Properties of ZnS Films Deposited by Radio Frequency Magnetron Sputtering

In this work, zinc sulfide (ZnS) thin films were prepared by radio frequency (RF) magnetron sputtering on glass substrates. The effects of sputtering power, working pressure, substrate temperature and annealing treatment on the structural and optical properties of ZnS films were studied using X-ray diffraction and UV-visible spectrometer in detailed.

Properties of Li-Doped ZnO Films Deposited on Diamond Films

Li-doped zinc oxide (ZnO) films were deposited on nucleation side of freestanding diamond (FSD) films by the radio frequency magnetron sputtering method. The effect of oxygen partial pressure on structural, optical and electrical properties of the ZnO films was investigated by X-ray diffraction (XRD) Raman spectroscopy, semiconductor characterization system and Hall effect measurement system. The results showed that the introduction of oxygen as a reactive gas was helpful to improve the crystalline quality of Li-doped ZnO films.

Effect of Oxygen Partial Pressure on Properties of ZnO Films Deposited on Freestanding Diamond Films

Highly c-axis-oriented ZnO films were deposited successfully on the nucleation sides of freestanding diamond (FSD) films by the direct current (DC) magnetron sputtering method in an oxygen (O2) + argon (Ar) gas mixture. The effect of oxygen partial pressure on properties of ZnO films was investigated by X-ray diffraction (XRD). The results showed that when flux ratio of argon to oxygen was 1, the ZnO films had a better crystalline quality.