绒面ZnO:Al(ZAO)透明导电薄膜的制备

利用中频交流磁控溅射方法，采用氧化锌铝(98wt％ZnO 2wt％A12O3)陶瓷靶材制备了绒面ZAO(ZnO：Al)薄膜，考察了所制备的绒面ZAO薄膜与绒面SnO2：F薄膜在绒度、粗糙度、表面形貌以及电学性质的差异，利用原子力显徽镜对薄膜表面形貌进行了分析并计算出薄膜表面粗糙度，利用紫外可见分光光度计和电阻测试仪测量了薄膜的光学、电学特性。结果表明：所制备的绒面ZAO薄膜具有与绒面SnO2：F薄膜相比拟的各种性能，在非晶硅太阳电池中具有潜在的应用前景。     

第12届中国光伏大会暨国际光伏展览会优秀论文选登(八) 超高浓度钛掺杂硅薄膜的制备及光电特性研究

将磁控溅射和热丝化学气相沉积相结合,制备出超高浓度钛掺杂的氢化非晶硅薄膜。通过光发射谱(OES)分析了热丝加热前后直流溅射辉光特性,结果表明热丝加热与否对直流溅射过程的影响不大。俄歇电子能谱显示钛在薄膜中是均匀分布的,改变磁控溅射的功率可控制薄膜中钛的含量,薄膜在可见和红外光的吸收随钛浓度的增加而显著增强。掺钛非晶硅薄膜仍表现出半导体特性,电阻率随着温度的降低而提高,满足变程跳跃电导输运机制。采用激光熔融(PLM)对薄膜进行退火,薄膜晶化率达50%以上。晶化的掺钛硅薄膜仍保持较高的可见-红外波段的光吸收。     

超高浓度钛掺杂硅薄膜的制备及光电特性研究

将磁控溅射和热丝化学气相沉积相结合,制备出超高浓度钛掺杂的氢化非晶硅薄膜.通过光发射谱(OES)分析了热丝加热前后直流溅射辉光特性,结果表明热丝加热与否对直流溅射过程的影响不大.俄歇电子能谱显示钛在薄膜中是均匀分布的,改变磁控溅射的功率可控制薄膜中钛的含量,薄膜在可见和红外光的吸收随钛浓度的增加而显著增强.掺钛非晶硅薄膜仍表现出半导体特性,电阻率随着温度的降低而提高,满足变程跳跃电导输运机制.采用激光熔融(PLM)对薄膜进行退火,薄膜晶化率达50％以上.晶化的掺钛硅薄膜仍保持较高的可见-红外波段的光吸收.     

沉积温度和激光刻线功率对a-Si材料H含量及电池组件效率的影响

系统研究了非晶硅本征层的沉积温度和激光刻线功率对薄膜电池组件性能的影响。各非晶硅薄膜(P层、I层和N层)采用等离子体增强化学气相沉积(PECVD)制备。I层的光学带隙随着沉积温度的升高而降低,同时也引起电池转换效率的变化。采用傅里叶红外分析检测I层的H含量及键合方式,H含量及键合方式的变化是引起光学带隙变化的根本原因。激光刻线的形貌采用光学显微镜作微观分析,而采用不同激光功率刻线后,薄膜电池的性能也有所差异,结果显示7.5μJ是最合适的功率。     

氢注入在硅异质结太阳电池a-Si:H窗口层中的研究

基于热丝化学气相沉积(Cat-CVD)系统开展氢注入对超薄(<10 nm)氢化非晶硅(a-Si:H)薄膜特性改善的研究,发现适当的氢注入可提高薄膜内的氢含量、降低其微结构因子并展宽其光学带隙.将该方法用于处理硅异质结(SHJ)太阳电池入光侧的本征非晶硅(i-a-Si:H)及N型非晶硅(n-a-Si:H)薄膜钝化层,可显...     

用热丝法制备优质稳定非晶硅薄膜的研究

系统地研究了低压热丝化学汽相沉积技术中沉积气压，衬底温度，钨丝温度等参量对氢化非晶硅膜结构，光电特性及稳定性的影响。结果表明，沉积气压是影响非晶硅原最主要参数，在优化沉积参数的条件下制备非晶硅，其稳定性有很大改进。     

反应磁控溅射制备带隙可调Si1-x Gex 薄膜

采用反应磁控溅射法制备非晶硅锗(Si1-x Gex)半导体薄膜,并对其组分、结构、光学性质及影响光学性质的因素进行研究。结果表明:该方法简单、成本低,且制备的非晶Si1-x Gex薄膜成分均匀、表面质量好、光学吸收系数高、带隙可调。另外提高氢气分压可使薄膜带隙升高,而低于300℃的衬底温度调节对薄膜的带隙影响不明显,退火温度对薄膜的带隙也有影响,高于800℃退火时,薄膜开始微晶化且光学带隙迅速减小。     

真空气相沉积制备碲化镉薄膜的电学和光学特性

用真空气相9沉积法，同时蒸发Cd和Te材料，在玻璃衬底上沉积CdTe薄膜。对CdTe薄膜掺杂In，并氮气作保护气体，在不同温度和时间下对薄膜进行热处理，研究薄膜的电学特性和光学特性。结果表明，用真空气相沉积法制备的CdTe薄膜的电学、光学特性和由其他方法制备的CdTe薄膜的电学和光学特性基本一致。     

硅氧合金薄膜及其在高效纳米硅薄膜叠层太阳电池中的应用研究

系统研究两种不同形态的硅氧合金薄膜,用甚高频PECVD系统制备的非晶硅氧和纳米硅氧薄膜的特性,以及其在纳米硅薄膜叠层薄膜太阳电池中的应用。实验中主要通过对不同的气体流量比的优化、沉积功率和沉积压力的优化,分别制备出光学带隙约为2.1 e V,折射率约为3的a-SiO_x∶B∶H薄膜,作为非晶硅顶电池的p1层,以及带隙为2.2~2.5 e V,折射率为2.0~2.5,晶化率为20%~50%的nc-SiO_x∶P∶H薄膜,作为非晶硅/纳米硅叠层电池的中间反射层和纳米硅的底电池n2层。最后将优化后的a-SiO_x∶B∶H和nc-SiO_x∶P∶H薄膜应用到非晶硅/纳米硅薄膜叠层电池中,在0.79 m~2的玻璃基板上制备出初始峰值功率为101.1 W、全面积初始转换效率为12.8%、稳定峰值功率为87.3 W、全面积稳定转换效率为11.1%的非晶硅/纳米硅叠层电池。     

微晶硅薄膜的光稳定性与微结构的关系

利用甚高频等离子体增强化学气相沉积技术,通过改变功率密度和沉积压强制备了三系列微晶硅薄膜。采用拉曼光谱、XRD与电导率分析技术,研究在光照条件下微晶硅薄膜的光学特性,光电导衰退与晶化率、沉积速率、晶粒尺寸间的关系。研究发现:随着晶化率的增加,微晶硅薄膜的光电导衰退率逐渐减小;随着沉积气压的增加,相同晶化率的薄膜的光稳定性降低。在光照50h后,薄膜的光电导衰退基本达到饱和。     

复合绒面透明导电薄膜研究

在常规非晶硅电池绒面SnO2衬底上，采用Zn：Al重量比为5％的金属靶直流反应磁控溅射沉积ZnO，构成复合绒面SnO2／ZnO透明导电膜。控制适当ZnO厚度，既能保持SnO2绒面效果，又可阻挡H离子对SnO2的还原作用，可作为微晶硅电池的前电极。文中对ZnO沉积条件以及复合膜的形貌、电光性能进行了讨论。     

TCO and light trapping in silicon thin film solar cells

For thin film silicon solar cells and modules incorporating amorphous (a-Si:H) or microcrystalline (μc-Si:H) silicon as absorber materials, light trapping, i.e. increasing the path length of incoming light, plays a decisive role for device performance. This paper discusses ways to realize efficient light trapping schemes by using textured transparent conductive oxides (TCOs) as light scattering, highly conductive and transparent front contact in silicon p–i–n (superstrate) solar cells. Focus is on the concept of applying aluminum-doped zinc oxide (ZnO:Al) films, which are prepared by magnetron sputtering and subsequently textured by a wet-chemical etching step. The influence of electrical, optical and light scattering properties of the ZnO:Al front contact and the role of the back reflector are studied in experimentally prepared a-Si:H and μc-Si:H solar cells. Furthermore, a model is presented which allows to analyze optical losses in the individual layers of a solar cell structure. The model is applied to develop a roadmap for achieving a stable cell efficiency up to 15% in an amorphous/microcrystalline tandem cell. To realize this, necessary prerequisites are the incorporation of an efficient intermediate reflector between a-Si:H top and μc-Si:H bottom cell, the use of a front TCO with very low absorbance and ideal light scattering properties and a low-loss highly reflective back contact. Finally, the mid-frequency reactive sputtering technique is presented as a promising and potentially cost-effective way to up-scale the ZnO front contact preparation to industrial size substrate areas.     

ZnO:Al绒面透明导电薄膜的制备及分析

利用中频脉冲磁控溅射方法,采用Al掺杂(质量百分比2%)的Zn(纯度99.99%)金属材料为靶材制备平面透明导电ZnO:Al(ZAO)薄膜。利用湿法腐蚀方法,将平面ZAO薄膜在0.5%的稀盐酸中浸泡一定时间后,形成表面凹凸起伏的绒面结构。研究了平面ZAO薄膜的结构特性以及衬底温度、溅射功率和腐蚀时间对绒面ZAO薄膜表面形貌的影响,并对腐蚀前后薄膜的电阻变化进行了分析。结果表明:高温、低功率条件下制备的绒面ZAO薄膜表面形貌较好,在硅薄膜太阳电池中具有潜在的应用前景。     

Optical properties of tungsten and titanium oxide thin films prepared by plasma sputter deposition

Tungsten oxide and titanium oxide thin films were prepared by RF reactive magnetron sputter deposition. The stationary and rotating substrate holders were applied to analyze the rotating effect. The optical properties and thicknesses of oxide films were determined by a proposed optical model and the measured transmittance spectra. The dispersed refractive indices of thin films have a wide range distribution in different sputtering conditions. In the situation of rotating substrate holder, the refractive index was lower than that of the stationary substrate holder. Also, amorphous TiO₂ structure can be prepared by using rotating substrate holder. The transmittance spectrum of crystalline TiO₂ reveals that the textured structure on the film surface affects the transmittance characteristic.     

Reduction of amorphous incubation layer by HCl addition during deposition of microcrystalline silicon by hot-wire chemical vapor deposition

The amorphous incubation layer, which is formed in the initial growth stage of hydrogenated microcrystalline silicon (μc-Si:H) thin film deposited at low temperature, is harmful to the electric properties of film. In this study, the effect of the addition of HCl gas on the reduction of such an amorphous incubation layer was investigated during the silicon deposition on a glass substrate at 220 °C by hot-wire chemical vapor deposition process using the Raman spectroscopy, the X-ray diffraction and the field-emission scanning electron microscopy. In the initial stage of deposition where the silicon film deposited without HCl addition consisted almost entirely of the amorphous incubation layer; highly crystalline silicon films could be deposited with HCl addition. As the flow rate of HCl increased, the crystallinity of silicon films increased but the film growth rate decreased. The surface morphology of films prepared with HCl addition became smoother with smaller grain size than that prepared without HCl.     

Structure changes and optical properties of Mg2Ni switchable mirrors

A multilayer film of Mg and Ni was prepared by dc/ac magnetron sputtering and annealed below 623 K in vacuum to obtain polycrystalline Mg₂Ni thin films. The phase transformation during heating process and optical switching properties of the films were investigated. The influence of the original crystalline state of Mg₂Ni films on optical switching properties such as transmission, optical band gaps and the cycle times was discussed. The indirect optical band gaps of the fully hydrogenated amorphous Mg₂Ni films were estimated by linear extrapolation.     

Surface textured MF-sputtered ZnO films for microcrystalline silicon-based thin-film solar cells

Highly conductive and transparent aluminum-doped zinc oxide (ZnO:Al) films were prepared by reactive mid-frequency (MF) magnetron sputtering at high growth rates. By varying the deposition pressure, pronounced differences with respect to film structure and wet chemical etching behavior were obtained. Optimized films develop good light-scattering properties upon etching leading to high efficiencies when applied to amorphous (a-Si:H) and microcrystalline (μc-Si:H) silicon-based thin-film solar cells and modules. Initial efficiencies of 7.5% for a μc-Si:H single junction and 9.7% for an a-Si:H/μc-Si:H tandem module were achieved on an aperture area of 64 cm².     

Development of highly efficient thin film silicon solar cells on texture-etched zinc oxide-coated glass substrates

ZnO films prepared by magnetron sputtering on glass substrates and textured by post-deposition chemical etching are applied as substrates for p–i–n solar cells. Using both rf and dc sputtering, similar surface textures can be achieved upon etching. Excellent light trapping is demonstrated by high quantum efficiencies at long wavelengths for microcrystalline silicon solar cells. Applying an optimized microcrystalline/amorphous p-layer design, stacked solar cells with amorphous silicon top cells yield similarly high stabilized efficiencies on ZnO as on state-of-the-art SnO₂ (9.2% for a-Si/a-Si). The efficiencies are significantly higher than on SnO₂-coated float glass as used for module production.     

Electrical and optical properties of ZnO thin film as a function of deposition parameters

Al-doped zinc oxide (AZO) and undoped zinc oxide (ZO) films have been prepared by rf magnetron sputtering. Films with low resistivities were achieved by using an Al-doped ZnO target and films with higher resistivities can be obtained by introducing oxygen during deposition. An AZO thin film which was fabricated with an rf power of 180 W, a sputtering pressure of 10 mTorr and thickness of 5000 Å showed the lowest resistivity of 1.4×10⁻⁴ Ω cm and transmittance of 95% in the visible range, and ZO film made by reactive sputtering with the above 10% oxygen content had the highest resistivity of 6×10¹⁴ Ω cm.     

Electrical properties of a-Si:H thin films as a function of bonding configuration

Hydrogenated amorphous silicon (a-Si:H) thin films were fabricated by Radio Frequency (RF) magnetron sputtering. For solar-cell applications, a-Si:H layers are required to show low dark conductivity and high photoconductivity and, thus, high photosensitivity. Hydrogen flow ratio and working pressure were mainly adjusted to control bonding configurations and hydrogen concentration in the films. At a high working pressure of 12 mTorr, all of the prepared amorphous and microcrystalline silicon films showed a dominant IR absorption peak at 2100 cm⁻¹, which indicates a Si-H₂ stretching mode, grain boundaries and microvoids. When the working pressure was decreased to as low as 3 mTorr with a hydrogen flow ratio of 0.1, the bonding configuration of the films was mainly Si-H as determined by the dominant IR absorption peak at 2000 cm^−1, and the photosensitivity of the films was maximized to 760.