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Amorphous Er2O3 films are deposited on Si (001) substrates by using reactive evaporation. This paper reports the evolution of the structure, morphology and electrical characteristics with annealing temperatures in an oxygen ambience. X-ray diffraction and high resolution transimission electron microscopy measurement show that the films remain amorphous even after annealing at 700 °C. The capacitance in the accumulation region of Er2O3 films annealed at 450 °C is higher than that of as-deposited films and films annealed at other temperatures. An Er2O3/ErOx/SiOx/Si structure model is proposed to explain the results. The annealed films also exhibit a low leakage current density (around 1.38 × 10−4 A/cm2 at a bias of −1 V) due to the evolution of morphology and composition of the films after they are annealed.

Tb-doped Zinc oxide (ZnO:Tb) films were prepared by RF reactive magnetron sputtering of a Zn target with some Tb-chips attached. The results show that the appropriate Tb ions incorporated into ZnO films can improve the structural and electrical properties of ZnO films. Photoluminescence (PL) measurements show that the characteristic emission lines correspond to the intra-4fn-shell transitions in Tb3+ ions at room temperature. Under the optimal conditions, the ZnO:Tb films were prepared with the lowest resistivity (ρ) of 9.34 × 10−4Ωcm, transmittance over 80% at the visible region and the strong blue emission.

Solar thermophotovoltaic (STPV) generator is a popular energy converter due to providing low noise, low thermal mechanical stress and portability. It has the ability to exceed the efficiency of pure solar photovoltaic system. An idealized STPV generator is a reversible heat-engine, offering a theoretical efficiency of over 80%, but the actual conversion efficiency of STPV generator is still low due to the mistuned spectral property between the thermal selective emitter and the TPV cell. One key issue in developing the STPV generator with high performance is the spectral matching between the thermal radiation spectrum of radiator and the spectral response of photovoltaic cell in visible and near-infrared region, which usually lies between the visible and the near-infrared region. High-temperature spectral emissivity of rare earth oxide is of special interest, because the radiation has a narrow band of wavelengths in the near infrared and infrared region from 900 to 3000 nm. In this work, the thermal-selective film Er2O3 emitter is fabricated by post-oxidation of Er film deposited on Si substrate through using electron-beam gun evaporation. Based on the X-ray diffraction results, the Er2O3 film is of cubic phase structure and well-crystallized when the oxidation temperature is 700℃, and the Si substrate has no obvious influence on the crystal structure of Er2O3 film. According to the X-ray photoelectron spectroscopy results of the Er2O3 film after thermal oxidation at 700℃, the atomic ratio of Er/O is stoichiometric. In order to obtain the selective emission characteristic of the Er2O3 film, a measurement system is designed. The system consists of two major portions, i.e., one is a near infrared spectrometer purchased from Ocean Optics, the other is a high-temperature emission characteristic tester which can provide oxyhydrogen flame to heat the sample by using an electronic impulse ignition to torch the hydrogen-oxygen mixture. The oxyhydrogen flame passes through the nozzle and sprays vertically on the surface of the thermal-selective emitter sample. The facula of the oxyhydrogen flame convergence is very small (facula diameter:~0.8 cm), and the highest temperature achieved is about 2500℃. The measurement condition of selective emission performance of the Er2O3 film emitter coincides with the application characteristic of STPV generator. The emission performance result of the film emitter at 700℃ shows a typical gray-body emission characteristic. The measurements carried out at 900 and 1100℃ show that the Er2O3 film has a distinct emittance spectrum at 1550 nm corresponding to Er3+, and the intensity of the selective emission peak strengthens with the measuring temperature or film thickness increasing. The thermal-selective film Er2O3 emitter is found to have emission spectrum suitable for efficient matching with the infrared response of GaSb photovoltaic cell.

HfGdO high-k gate dielectric thin films were deposited on Ge substrates by radio-frequency magnetron sputtering. The current transport properties of Al(Pt)/HfGdO/Ge MOS structures were investigated at room temperature. The results show that the leakage currents are mainly induced by Frenkel-Poole emissions at a low electric field. At a high electric field, Fowler Nordheim tunneling dominates the current. The energy barriers were obtained by analyzing the Fowler Nordheim tunneling characteristics, which are 1.62 eV and 2.77 eV for Al/HfGdO and Pt/HfGdO, respectively. The energy band alignments for metal/HfGdO/Ge capacitors are summarized together with the results of current-voltage and the x-ray photoelectron spectroscopy.

The SiC:Tb films were deposited on porous silicon substrate by rfsputtering. The samples prepared were annealed in N2 atmosphere at different temperatures, and Fourier transform infrared has been used to characterize the structure of them. We observed a strong photoluminescence(PL) spectrum at room temperature in the ultraviolet(UV) and visible regions. We found that the UV emission has obvious changed and a slight blue shift was observed with the change of annealing temperature. The UV and visible PLs were attributed to oxygen deficit center(ODC) and Tb3+ respectively.

Highly oriented polycrystalline ZnO films have been prepared by rf actively sputtering technique. We have investigated the structural and optical properties of ZnO films. x-ray diffraction was employed to analyze the influence of the post-treatment on the properties of ZnO thin films. The grain size increases with annealing temperature. The shift of the diffraction peak position from its normal powder value was observed. The photoluminescence (PL) spectra of these samples consist of one emission peak centred at 2.9eV.The intensities of PL peaks decrease with increasing annealing temperature. We propose that the emission comes from the interstitial Zn.