Electron Beam Evaporation Preparation Of Zno: Al Film And Photoelectric Properties Of General Physics Experiment Reform

Zinc oxide as a wide band-gap (3.3eV) compound semiconductor with wurtzite crystal structure, is gaining importance for the possible application as a semiconductor laser, due to its ultraviolet emission at room temperature. It has high exciton binding energy of 60 meV, which ensures efficient UV emission from the exciton and make it suitable for UV laser-emitting devices. Since the first observation of the stimulated ultraviolet emission at room temperature, ZnO has become another hotspot in the region of UV light emitting researching. Al-doped ZnO (AZO) thin films are emerging as an alternative potential candidate for ITO (Sn-doped In2O3) films recently not only because of their comparable optical and electrical properties (high optical transparency in the visible range, infrared reflectance and low d.c. resistivity) to ITO films, but also because of their higher thermal and chemical stability under the exposure to hydrogen plasma than ITO.In this paper, high quality transparent and conductive Al-doped ZnO thin films on quartz substrates are prepared by electron beam evaporation technique. X-ray diffraction (XRD), photoluminescence spectra, transmittance spectra, and Van der Pauw experiment are employed to study the electrical and optical properties of AZO films. The X-ray diffraction spectra show that preferential orientation of the ZnO:Al polycrystal with the c-axis perpendicular to the substrate surface has formed. All samples demonstrate a hexagonal structure. The intense UV near-edge emission peaks are observed. Their position shifts to low energy and becomes sharper with the increase of annealing temperature. Deep-level green emissions are weak. The tail of localized states in the band gap is formed,and in the high temperature range, the behavior of metallic conduction can be observed. According to the temperature dependence of conductivity and Hall mobility, the conductance mechanism is investigated. The main scattering mechanism is ionized impurity scattering and acoustical phonon scattering. The experimental results show that the high quality of ZnO.Al films were obtained.In order to satisfy the requirement of knowledge economy epoch and reform of current common physics experiment teaching in university, we can introduce some experiments about the new material ZnO:Al studied in this paper into the electromagnetic researching experiments, such as Hall measurements of semiconductor material in room and different temperature. In this way, we can not only widen students' horizon of knowledge, but also train elaborative faculty of independence and the spirit of exploring. So introducing this experiment into universities is an effective approach to inspire the interest of scientific research and train the faculty of innovation.