Reduction of light-induced defects by nano-structure tailored silicon solar cells using low-cost TCO substrates

In order to overcome the light-induced defects of hydrogenated amorphous silicon solar cells, we propose novel silicon material, called nano-structure tailored silicon, where nano-sized crystallites embedded in the amorphous silicon matrix homogeneously. We have applied low-cost TCO substrates to their solar cells, so we obtained a stabilized efficiencies (7.39%) higher than standard a-Si:H solar cells (7.25%) on a low-cost substrate.     

p型透明导电氧化物CuAlO2薄膜的研究进展

透明导电氧化物(TCO)的出现开拓了光电子器件研究的新领域.但p型TCO的相对匮乏严重制约了透明氧化物半导体(TOS)相关器件的开发与应用.CuAlO2作为一种天然的p型TCO成为近年来p型TCO的研究热点.介绍了p型TCO的研究现状,综述了不同制备方法制备p型CuAlO2薄膜的研究进展,以及在器件方面的应用,并对其前景进行了展望.     

Investigation of lateral parameter variations of Al-doped zinc oxide films prepared on glass substrates by rf magnetron sputtering

Sputter-deposited Al-doped zinc oxide (ZnO : Al) is an interesting transparent conductive oxide (TCO) material for application in electronic devices and thin-film solar cells. A phenomenon in the planar magnetron sputtering of the ZnO : Al films that is not well investigated as yet are the laterally non-uniform film properties resulting from the laterally inhomogeneous erosion of the target material, whereby the lateral distribution of the film properties depends strongly on the sputtering parameters. In this work, the lateral distributions of the electrical, optical, and surface structure properties of the ZnO : Al films prepared by the rf magnetron sputtering on glass substrates are investigated across a distance of 64 mm using the four-point probe technique, optical transmission and reflection measurements, X-ray diffraction, and scanning electron microscopy. We find that the lateral variations of the parameters of the ZnO : Al films prepared by the rf magnetron sputtering can be reduced to acceptable levels by optimising the deposition parameters. Hence, it seems that the sputter-deposited ZnO : Al is a promising TCO material for large-area thin-film solar cells.     

特色功能材料--透明导电氧化物薄膜

透明导电氧化物(TCO)是一种特色鲜明的功能材料,以其接近金属的电导率、可见光高透射率、红外区高反射率及其它半导体特性,可应用于平板显示器件、太阳能光伏电池、反射热镜、气体敏感器件、特殊功能窗口涂层以及光电子、微电子、真空电子器件等领域.综述了透明导电氧化物薄膜的基本特性、制备方法及应用,并展望了其发展前景.     

Investigation on structural, electrical and optical properties of tungsten-doped tin oxide thin films

Tungsten-doped tin oxide (SnO₂:W) transparent conductive films were prepared on quartz substrates by pulsed plasma deposition method with a post-annealing. The structure, chemical states, electrical and optical properties of the films have been investigated with tungsten-doping content and annealing temperature. The lowest resistivity of 6.67 × 10^− 4 Ω cm was obtained, with carrier mobility of 65 cm² V^− 1 s^− 1 and carrier concentration of 1.44 × 10²⁰ cm^− 3 in 3 wt.% tungsten-doping films annealed at 800 °C in air. The average optical transmittance achieves 86% in the visible region, and approximately 85% in near-infrared region, with the optical band gap ranging from 4.05 eV to 4.22 eV.     

Effect of thermal annealing on the structural and optical properties of nanostructured zinc oxide thin films prepared by pulsed laser ablation

Zinc oxide (ZnO) films are prepared by pulsed laser ablation, on an optically flat quartz substrate for different deposition time. The influence of annealing temperature, on the structural and optical properties of ZnO films is investigated systematically using X-ray diffraction (XRD), energy dispersive X-ray analysis (EDX), scanning electron microscopy (SEM), atomic force microscopy (AFM), Raman spectra, UV-vis spectroscopy and photoluminescence spectroscopy (PL). The XRD pattern shows that the as-deposited films are amorphous and the annealed films are polycrystalline. The average size of the crystalline grains varies from 9 to 26 nm in the films. The SEM and AFM images reveal uniform distribution of grains in the films and the grains are in the nanoscale dimension. Raman spectra suggest the hexagonal wurtzite phase for the ZnO films. The UV-visible spectra show an increase in transmittance with annealing temperature. The observation of very intense PL emission from the films annealed at 773 K, suggest the suitability of these films for applications as light emitters in the visible region. The ability to produce the stochiometric ZnO thin films with reproducible structural, morphological and optical characteristics should be useful as a suitable window material for practical industrial solar cell and display devices.     

Anode material properties of Ga-doped ZnO thin films by pulsed DC magnetron sputtering method for organic light emitting diodes

This study examined the anode material properties of Ga-doped zinc oxide (GZO) thin films deposited by pulsed DC magnetron sputtering along with the device performance of organic light emitting diodes (OLEDs) using GZO as the anode. The structure and electrical properties of the deposited films were examined as a function of the substrate temperature. The electrical properties of the GZO film deposited at 200 °C showed the best properties, such as a low resistivity, high mobility and high work function of 5.3 × 10^− 4Ω cm, 9.9 cm²/Vs and 4.37 eV, respectively. The OLED characteristics with the GZO film deposited under the optimum conditions showed good brightness > 10,000 cd/m². These results suggest that GZO films can be used as the anode in OLEDs, and a lower deposition temperature of 200 °C is suitable for flexible devices.     

Optimization of process parameters for sputtering of ceramic ZnO:Al2O3 targets for a-Si:H/μc-Si:H solar cells

Aluminum doped ZnO layers with a thickness of 800 nm were deposited dynamically by d.c. magnetron sputtering from a ceramic planar ZnO: Al₂O₃ target (1 wt.%). A wide range of process parameters, namely oxygen partial pressure, total pressure and power, was covered, while temperature was held constant at 300 °C. Visual absorption in the range of 2.3-4.7% and resistivities between 380 and 2150 µΩcm were obtained. In addition static imprints were performed to reveal the dependence of layer properties on target erosion. It was shown, that films deposited from targets with a race track deeper than 1.8 mm had very stable etching morphologies as well as optical and electrical properties in the range of the observed process parameters. In contrast, a new target yields very different etching structures and an increased resistivity.     

模块化UPS对客户TCO的影响

随着计算机和网络设备的普及,各行各业对交流电的可靠性要求越来越高,交流不间断电源系统(UPS)的应用也越来越广泛。同时,由于市场竞争力等因素的考虑,用户越来越关注UPS的TCO(Total Cost of Ownership)。本文重点探讨模块化UPS相对传统UPS在TCO方面的优势。     

Al3+ doping induced changes of structural,morphology, photoluminescence,optical and electrical properties of SnO2 thin films as alternative TCO for optoelectronic applications

Highly transparent and conductive pure (SnO₂) and aluminum doped tin oxide (Al:SnO₂) thin films were deposited on glass substrates by the sol-gel spin-coating method. The structural, morphological, optical and electrical properties of the prepared thin films at different doping rates have been studied. X-ray diffraction results revealed that all the films were polycrystalline in nature with a tetragonal rutile structure. SEM images of the analyzed films showed a homogeneous surface morphology, composed of nanocrystalline grains. The EDS results confirmed the presence of Sn and O elements in pure SnO₂ and Sn, O, Al in doped SnO₂ thin films. The optical results revealed a high transmittance greater than 85% in the visible and near infrared and a band gap varying between 3.82 and 3.89 eV. PL spectra at room temperature showed that the most dominant defects correspond to oxygen vacancies. A low resistivity of order varying between 10^?3 and 10^?4 Ω cm and a high figure of merits ranging between 10^?3 and 10^?2 Ω^?1 in the visible range were obtained. The best performances were obtained for samples containing 2 at. % Al, which could be used as an alternative TCO layer for future optoelectronic devices.