非晶硅太阳电池应用和开发的新进展

评述了ａ－Ｓｉ电池的工艺优势、开发水平，市场现况、应有和领域及发展趋向。     

激光在非晶硅薄膜太阳能电池制造中的应用

人类进入21世纪,能源问题更为突出,常规能源的匮乏不足,面临在有限资源和环保严格要求的双重制约下实现经济和社会可持续发展已成为全球热点问题。传统的石油、煤等化石能源的开发利用,在一定程度上带来了环境污染、温室效应     

非晶硅薄膜太阳能电池特性研究

介绍了太阳能电池的工作原理,并给出了太阳能电池的物理模型。设计了室内测试非晶硅薄膜电池输出特性的实验,并对实验结果进行分析。搭建了小型独立光伏发电系统,给出系统的工程设计结构。实验结果表明,太阳能电池的转换效率与室内实验所测得的结果相吻合,证明该系统具有可靠性和高效性。     

非晶硅薄膜光伏电池结构参数分析

考虑到nip型[ITO/a-Si(n)/a-Si(i)/a-Si(p)/Al]非晶硅光伏电池的各膜层厚度、掺杂浓度等因素,对非晶硅光伏电池的转换效率、填充因子、开路电压等性能参数进行了数值分析与讨论。结果表明,随p型层厚度的增加,光伏电池的短路电流密度、转换效率、开路电压值都有所增加。当本征层的厚度增加时,短波段内的光谱响应变差、内量子效率下降。当n型层厚度为5 nm,本征层厚度为5 nm,p型层厚度为10μm,受主掺杂浓度为2.5×1019cm-3,施主掺杂浓度为1.5×1016cm-3时,转换效率可达9.728%。     

PIN型非晶硅薄膜太阳电池仿真研究

运用AMPS软件,对TCO/p-a-SiC:H/i-a-Si:H/n-a-Si:H/metal型非晶硅薄膜太阳电池进行了仿真研究,重点模拟和分析了电池性能参数随i层和n层厚度变化的规律.结果表明,为了获得电池转换效率和短路电流密度的最大值,n 层非晶硅薄膜应尽可能地减小厚度,而i层非晶硅薄膜厚度最好控制在500～700 nm范围内.     

太阳能电池组件用PVDF薄膜背板材料可靠性研究

本文选取6种不同型号背板按常规工艺制备的晶硅光伏组件,放入环境试验箱进行紫外、温度循环测试,通过环境叠加试验和加严测试方法,对不同背板组件的性能进行对比分析。结果表明:在2倍的高低温循环试验以及紫外与高低温循环叠加试验后,厂家C和厂家D氟膜在焊带位置出现开裂问题,裂纹深度贯穿于氟膜层,此种问题通过背板整体的力学性能测试并不能反映出来。本文研究结果,为背板可靠性验证和生产选用提供了数据基础。     

光诱导化学汽相淀积非晶硅薄膜及其在太阳电池中的应用

本文较系统地评述了光诱导化学汽相淀积(LCVD)技术淀积非晶硅薄膜的开发现状,主要介绍了LCVD淀积非晶硅薄膜 的机理.评价了LCVD淀积非晶硅薄膜的电学和光学特性,最后介绍了这种薄在制备晶硅太阳电池方面的应用.     

非晶硅薄膜太阳能电池激光除边工艺研究

为了解决在非晶硅薄膜太阳能电池的制备中,喷砂除边工序存在污染大、加工一致性不佳等问题,使用1064nm脉冲光纤激光器,在加工速率3500mm/s、功率30W、重复频率80kHz、填充线间距0.05mm的参量下,完成了激光除边,获得了清除区电阻大于1000MΩ的样品。根据实验效果确定了最佳光斑交叠比,x和y方向的最佳比值分别为0.83和0.88。结果表明,激光功率足够时,光斑交叠情况会明显影响除边的效率和效果,扫描速率应与重复频率和填充线间距匹配,从而在最佳效率下获得理想的加工效果。     

聚酰亚胺衬底柔性非晶硅薄膜电池集成串联组件的研究

研究了柔性Si基薄膜太阳电池集成串联组件的制备与关键技术。对导电栅线在柔性薄膜太阳电池集成串联组件中的重要性进行了模拟计算,对柔性薄膜太阳电池激光刻蚀进行了理论分析与实验优化,并对柔性Si基薄膜太阳电池集成串联组件进行了设计与研制。在聚酰亚胺(PI)衬底上,通过卷对卷磁控溅射与卷对卷等离子增强化学气相沉积(PECVD)依次沉积复合背反射层Ag/ZnO、Si基薄膜层和透明导电膜层,采用激光刻蚀与丝网印刷工艺相结合实现集成串联,制备了柔性非晶Si(a-Si)薄膜太阳电池集成串联组件。柔性单结集成串联组件有效面积转换效率达到了4.572%(AM0),开路电压Voc=5.065V,填充因子FF=0.552。     

n-Doped-layer free amorphous silicon thin film solar cells fabricated with the CuMg alloy as back contact metal

The feasibility of using CuMg alloy as back contact metal for n⁺-doped-layer free a-Si:H thin film solar cell (TFSC) has been investigated in this work. The ohmic-contact characteristic has been achieved by using the CuMg alloy as back contact metal. The proposed structure showed the typical solar cell current-voltage (I-V) characteristic. An initial efficiency of 4.3% has been obtained with a open-circuit voltage V_oc = 0.79 V, short-circuit current J_sc = 13.4 mA/cm² and fill factor F.F. = 0.40. Furthermore, the experimental results also showed the CuMg alloy was suitable for the replacement of n⁺-doped-layer with the production cost reduction of a-Si:H TSFC.     

p-Layer bandgap engineering for high efficiency thin film silicon solar cells

Spectroscopic ellipsometry (SE), high resolution transmission electron microscopy (HRTEM), atomic force microscopy (AFM) and optical transmittance measurements were used to study and establish a correlation between the open-circuit voltage (V_oc) of solar cells and the p-layer optical band gap (E_p). It is found that the ellipsometry measurement can be used as an inline non-destructive diagnostic tool for p-layer deposition in commercial operation. The analysis of ellipsometric spectra, together with the optical transmittance data, shows that the best p-layer appears to be very fine nanocrystallites with an E_p 1.95 eV. HRTEM measurements reveal that the best p-layer is composed of nanocrystallites ~9 nm in size. It is also found that the p-layer exhibits very good transmittance, as high as ~91.6% at ~650 nm. These results have guided us to achieve high V_oc value 1.03 V for thin film silicon based single junction solar cell.     

PI衬底柔性透明硅薄膜太阳能电池的制备及性能

利用硬质玻璃为载板,采用传统硅薄膜太阳能电池生产设备,在聚酰亚胺(PI)塑料薄膜衬底上沉积了B掺杂的ZnO(BZO)薄膜,并以此作为前电极制备了单节电池结构及多节串联一体结构的非晶硅(a-Si)太阳能电池;研究了PI衬底上BZO薄膜的光学及电学性能。结果表明,PI衬底上沉积BZO薄膜后在300~1 200 nm波长范围的透光率为76.63%,方块电阻19.7?/□。所制备的单节和多节串联一体结构的a-Si薄膜太阳能电池的转化效率分别达到6.45%和5.1%,封装后电池组件具有一定的透光性,透光率约达到30.2%。     

Improvement of hydrogenated amorphous silicon germanium thin film solar cells by different p-type contact layer

In this study, we report an appreciably increased efficiency from 6% up to 9.1% of hydrogenated amorphous silicon germanium (a-SiGe:H) thin film solar cells by using a combination of different p-doped window layers, such as boron doped hydrogenated amorphous silicon (p-a-Si:H), amorphous silicon oxide (p-a-SiO_x:H), microcrystalline silicon (p-µc-Si:H), and microcrystalline silicon oxide (p-µc-SiO_x:H). Optoelectronic properties and the role of these p-layers in the enhancement of a-SiGe:H cell efficiency were also examined and discussed. An improvement of 1.62 mA/cm² in the short-circuit current density (J_sc) is attributed to the higher band gap of p-type silicon oxide layers. In addition, an increase in open-circuit voltage (V_oc) by 150 mV and fill factor (FF) by 6.93% is ascribed to significantly improved front TCO/p-layer interface contact.     

Design of Ag nanograting for broadband absorption enhancement in amorphous silicon thin film solar cells

Light trapping is one of the key issues to improve the light absorption and increase the efficiency of thin film solar cells. The effects of the triangular Ag nanograting on the absorption of amorphous silicon solar cells were investigated by a numerical simulation based on the finite element method. The light absorption under different angle and area of the grating has been calculated. Furthermore, the light absorption with different incident angle has been calculated. The optimization results show that the absorption of the solar cell with triangular Ag nanograting structure and anti-reflection film is enhanced up to 96% under AM1.5 illumination in the 300–800 nm wavelength range compared with the reference cell. The physical mechanisms of absorption enhancement in different wavelength range have been discussed. Furthermore, the solar cell with the Ag nanograting is much less sensitive to the angle of incident light. These results are promising for the design of amorphous silicon thin film solar cells with enhanced performance.     

非、单晶硅太阳能电池组件比功率发电量对比研究

通过比较单晶硅与非晶硅比功率发电量,分析两者在太阳能发电功效上的具体差异.     

Improved photovoltaic properties of amorphous silicon thin-film solar cells with an un-doped silicon oxide layer

This paper proposes the use of undoped hydrogenated microcrystalline silicon oxide (μc-SiO_x:H) deposited on the n-μc-Si:H layer of amorphous silicon single-junction superstrate configuration thin-film solar cells produced through 40 MHz very high frequency plasma-enhanced chemical vapor deposition. Raman spectroscopy and optoelectronic analyses of the undoped μc-SiO_x:H thin film revealed that adding a small amount of oxygen into a μc-network results in a low optical absorption, wide band gap, high optical band gap E₀₄, high refractive index, reasonable conductivity, and crystalline volume fraction, which are advantageous properties in solar cells. Compared with a standard cell, the current density–voltage (J–V) characteristics of the cell with an undoped μc-SiO_x:H/n-μc-Si:H structure showed an enhancement in short-circuit current density J_sc from 13.32 to 13.60 mA/cm², and in conversion efficiency from 8.53% to 8.61%. The increased J_sc mechanism can be attributed to an improved light-trapping capability in the long wavelength range between 510 and 660 nm, as demonstrated by the external quantum efficiency.     

Hydrogen dilution on an undoped silicon oxide layer and Its application to amorphous silicon thin-film solar cells

This paper proposes the use of undoped hydrogenated microcrystalline silicon oxide (μc-SiO_x:H) deposited on an n-μc-Si:H layer of amorphous silicon single-junction superstrate-configuration thin-film solar cells produced using 40 MHz very high frequency plasma-enhanced chemical vapor deposition. We found that undoped μc-SiO_x:H thin film under optimized hydrogen dilution conditions had high crystallinity, high conductivity, a wide optical band gap, and a high refractive index, which are advantageous properties in solar cells. However, deposition at higher hydrogen dilutions degraded the quality and optoelectronic properties of the films, because the morphology of the films changed from microcrystalline to amorphous. These results suggest that the use of an optimized undoped μc-SiO_x:H layer improves a-Si:H thin-film solar cell performance through enhancement of the short-circuit current density J_sc. The increased J_sc can be attributed to an improved light-trapping capability in the long wavelength range, between 620 and 680 nm, as demonstrated by the external quantum efficiency. This technique also allows optimal conversion efficiency to be achieved. The results demonstrated that hydrogen dilution plays a dominant role in the improvement of film quality and solar cell performance; however, the tradeoff between refractive index and conductivity must be considered.     

A simple analytical model of thin films crystalline silicon solar cell with quasi-monocrystalline porous silicon at the backside

An analytical model that simulates the performance of an elementary thin silicon solar cell with a thin film quasi-monocrystalline porous silicon (QMPS) at the backside reflector is developed. A complete set of equations for the photocurrent generated under the effect of the reflected light is solved analytically in each region. The collection of the light absorbed by the QMPS layer has been discussed and the analytical solution of the light-generated current in this layer is derived. The maximum of the photocurrent density calculated in the present study is in accordance with the numerical values established by Bergmann et al. Furthermore, the influence that the layer's number of double porosities and high porosity have on the photovoltaic parameters is studied. It is demonstrated that the photovoltaic parameters increase with the number of double porosities that the layer might have in a given structure. When the QMPS layer is formed by three double-porosity layers 20%/80% and for a 5-μm-thick film c-Si, the backside reflector gives a total improvement of about 6 mA/cm² for the photocurrent density and 3.2% for the cell efficiency.     

Effect of the interface states on the cell parameters of a thin film quasi-monocrystalline porous silicon as an active layer

Unlike crystalline silicon, quasi-monocrystalline porous silicon (QMPS) layers have a top surface with small voids in the body. What is more pertinent to the present study is the fact that, at a given wavelength of interest for solar cells, these layers are often reported, in the literature, to have a higher absorption coefficient than crystalline silicon. The present study builds on existing literature, suggesting an analytical model that simulates the performance of an elementary thin QMPS (as an active layer) solar cell. Accordingly, the effects that the interface states located at the void-silicon interface and that the porosity of this material have on the cell parameters are investigated. Furthermore, the effects of the optimum base doping, QMPS thickness, and porosity on the photovoltaic parameters were taken into consideration. The results show that the optimum base doping depends on the QMPS thickness and porosity. For an 8 μm thickness, the film QMPS layer gives a 35.4 mA/cm² for short-circuit current density, 15% for conversion efficiency, and 527 mV for open-circuit voltage when the value of the interface states is about 10¹² cm⁻² and the base doping is about 2×10¹⁸ cm⁻³ under AM 1.5 conditions.