Electrical and optical properties of deep ultraviolet transparent conductive Ga2O3/ITO films by magnetron sputtering

Ga2O3/ITO films were prepared by magnetron sputtering on quartz glass substrates. The transmittance and sheet resistance of ITO films and Ga2O3/ITO films were measured by using a double beam spectrophotometer and four point probes. The effect of the ITO layer and Ga2O3 layer thickness on the electrical and optical properties of Ga2O3/ITO bi-layer films were investigated in detail. Ga2O3 (50 nm)/ITO (23 nm) films exhibited a low sheet resistance of 323 Ω/□ and high deep ultraviolet transmittance of 77.6% at a wavelength of 280 nm. The ITO layer controls the ultraviolet transmittance and sheet resistance of Ga2O3/ITO films. The Ga2O3 layer thickness has a marked effect on the transmission spectral shape of Ga2O3/ITO films in the violet spectral region.     

Manipulation of the Morphology of CdSe Nanostructures: The Effect of Si

The morphological manipulation, structural characterization, and photoluminescence properties of different CdSe nanocrystals are reported. Several different CdSe structures, including nanowires, nanorods, nanoparticles, and tetrapod crystals, have been grown on silicon substrates by means of simple, Si‐assisted chemical vapor deposition. By manipulating the growth driving force (i.e., the degree of supersaturation), the morphology of the CdSe nanocrystals can be varied sequentially from nanowires/nanorods to nanoparticles to tetrapod structures. The optical properties of the CdSe nanocrystals are investigated using photoluminescence spectroscopy. Some thermodynamic models are proposed to explain the results.     

直流磁控溅射ITO薄膜的正交试验分析

利用直流磁控溅射系统制备ITO薄膜,采用正交试验表格L32(48)安排试验.测试了薄膜的方阻和透过率,分析了8个工艺参数对薄膜电光特性的影响,其中沉积气压、氩氧流量比和退火温度的影响最大.分析得到优化工艺参数为:沉积气压2×133.322 4 mPa、氩氧流量比16∶0.5、退火温度427 ℃、靶基间距15、退火时间1 h、溅射功率300 W、退火氛围为真空、沉积温度227 ℃.在此工艺参数下制备的ITO薄膜方阻为17 Ω/□,电阻率为1.87×10-4Ω·cm,在可见光区域平均透过率为85.13%.     

锑化铟抛光片表面粗糙度优化研究

锑化铟是中波红外探测应用较广的材料。抛光片的表面粗糙度是影响器件性能的关键指标。研究了锑化铟化学机械抛光(Chemical Mechanical Polishing, CMP)液的pH值、氧化剂比例以及抛光液流速对锑化铟抛光片表面粗糙度的影响,并结合原子力显微镜(Atomic Force Microscope, AFM)和表面轮廓仪测试对抛光片的表面粗糙度进行了表征和优化。结果表明,当pH值为8、氧化剂比例为0.75%、抛光液流速为200 L/min时,InSb晶片的表面粗糙度为1.05 nm (AFM),同时晶片的抛光宏观质量较好。     

Optical and electrical properties and phonon drag effect in low temperature TEP measurements of AgSbSe2 thin films

Polycrystalline thin films of silver antimony selenide have been deposited using a reactive evaporation technique onto an ultrasonically cleaned glass substrate at a vacuum of 10-5 torr. The preparative parameters, like substrate temperature and incident fluxes, have been properly controlled in order to get stoichiometric, good quality and reproducible thin film samples. The samples are characterized by XRD, SEM, AFM and a UV-vis-NIR spectrophotometer. The prepared sample is found to be polycrystalline in nature. From the XRD pattern, the average particle size and lattice constant are calculated. The dislocation density, strain and number of crystallites per unit area are evaluated using the average particle size. The dependence of the electrical conductivity on the temperature has also been studied and the prepared AgSbSe2 samples are semiconducting in nature. The AgSbSe2 thin films exhibited an indirect allowed optical transition with a band gap of 0.64 eV. The compound exhibits promising thermoelectric properties, a large Seebeck coefficient of 30 mV/K at 48 K due to strong phonon electron interaction. It shows a strong temperature dependence on thermoelectric properties, including the inversion of a dominant carrier type from p to n over a low temperature range 9-300 K, which is explained on the basis of a phonon drag effect.     

Effects of substrate temperature on electrical and structural properties of copper thin films

This paper addresses the effects of substrate temperature on electrical and structural properties of dc magnetron sputter-deposited copper (Cu) thin films on p-type silicon. Copper films of 80 and 500 nm were deposited from Cu target in argon ambient gas pressure of 3.6 mTorr at different substrate temperatures ranging from room temperature to 250 °C. The electrical and structural properties of the Cu films were investigated by four-point probe and atomic force microscopy. Results from our experiment show that the increase in substrate temperature generally promotes the grain growth of the Cu films of both thicknesses. The RMS roughness as well as the lateral feature size increase with the substrate temperature, which is associated with the increase in the grain size. On the other hand, the resistivity for 80 nm Cu film decreases to less than 5 μΩ-cm at the substrate temperature of 100 °C, and further increase in the substrate temperature has not significantly decreased the film resistivity. For the 500 nm Cu films, the increase in the grain size with the substrate temperature does not conform to the film resistivity for these Cu films, which show no significant change over the substrate temperature range. Possible mechanisms of substrate-temperature-dependent microstructure formation of these Cu films are discussed in this paper, which explain the interrelationship of grain growth and film resistivity with elevated substrate temperature.     

Zr‐Doped Indium Oxide (IZRO) Transparent Electrodes for Perovskite‐Based Tandem Solar Cells

Parasitic absorption in transparent electrodes is one of the main roadblocks to enabling power conversion efficiencies (PCEs) for perovskite‐based tandem solar cells beyond 30%. To reduce such losses and maximize light coupling, the broadband transparency of such electrodes should be improved, especially at the front of the device. Here, the excellent properties of Zr‐doped indium oxide (IZRO) transparent electrodes for such applications, with improved near‐infrared (NIR) response, compared to conventional tin‐doped indium oxide (ITO) electrodes, are shown. Optimized IZRO films feature a very high electron mobility (up to ≈77 cm² V^?1 s^?1), enabling highly infrared transparent films with a very low sheet resistance (≈18 Ω □^?1 for annealed 100 nm films). For devices, this translates in a parasitic absorption of only ≈5% for IZRO within the solar spectrum (250–2500 nm range), to be compared with ≈10% for commercial ITO. Fundamentally, it is found that the high conductivity of annealed IZRO films is directly linked to promoted crystallinity of the indium oxide (In₂O₃) films due to Zr‐doping. Overall, on a four‐terminal perovskite/silicon tandem device level, an absolute 3.5 mA cm^?2 short‐circuit current improvement in silicon bottom cells is obtained by replacing commercial ITO electrodes with IZRO, resulting in improving the PCE from 23.3% to 26.2%.     

Nanostructured CuO/PANI composite as supercapacitor electrode material

An in-situ polymerization method has been employed to prepare CuO/PANI nanocomposite. The prepared samples have been characterized by X-ray diffraction (XRD), FTIR spectroscopy, field emission scanning electron microscopy (FESEM), and BET analysis. Application of the prepared samples has been evaluated as supercapacitor material in 1 M Na₂SO₄ solution using cyclic voltammetry (CV) in different potential scan rates, ranging from 5 to 100 mV s⁻¹, and electrochemical impedance spectroscopy (EIS). The specific capacitance of CuO/PANI has been calculated to be as high as 185 F g⁻¹, much higher than that obtained for pure CuO nanoparticles (76 F g⁻¹). Moreover, the composite material has shown better rate capability (75% capacitance retention) in various scan rates in comparison with the pure oxide (30% retention). EIS results show that the composite material benefits from much lower charge transfer resistance, compared to CuO nanoparticles. Moreover, much better cyclic performance has been achieved for the composite material.     

多层交替结构Ga2O3/ITO深紫外透明导电膜

Ga2O3/ITO alternating multilayer films were deposited on quartz glass substrates by magnetron sputtering.The effect of the multi-period on the structural,optical and electrical properties of Ga2O3/ITO alternating multilayer films was investigated by an X-ray diffractometer,a double beam spectrophotometer and the Hall system,respectively.A low sheet resistance of 225.5Ω/□ and a high transmittance of more than 62.9% at a 300 nm wavelength were obtained for the two-period alternating multilayer film with a thickness of 72 nm.     

高质量InAs单晶材料的制备及其性质

利用液封直拉法(LEC)生长了直径50mm〈100〉和〈111〉晶向的InAs单晶.分析研究了n型杂质Sn,S和p型杂质Zn,Mn的分凝特性、晶格硬化作用、掺杂效率等.利用X射线双晶衍射分析了晶体的完整性.对InAs晶片的抛光、化学腐蚀和清洗进行了分析,在此基础上实现了抛光晶片的开盒即用(EPI-READY).