Comparing Crystalline Silicon Solar Cells with Thin Film

１ＩｎｔｒｏｄｕｃｔｉｏｎＳｅｍｉｃｏｎｄｕｃｔｏｒｓｈａｖｅｂｅｅｎｅｍｅｒｇｅｄａｓｔｈｅｍｏｓｔｐｒｏｍｉｓｉｎｇｃｌａｓｏｆｍａｔｅｒｉａｌｓｔｈａｔｃａｎｃｏｎｖｅｒｔｓｕｎｌｉｇｈｔｄｉｒｅｃｔｌｙｉｎｔｏｅｌｅｃｔｒｉｃａｌｅｎｅｒｇｙ...

Research on the optimum hydrogenated silicon thin films for application in solar cells

Hydrogenated silicon （Si：H） thin films for application in solar ceils were deposited by using very high frequency plasma enhanced chemical vapour deposition （VHF PECVD） at a substrate temperature of about 170 ℃, The electrical, structural, and optical properties of the films were investigated. The deposited films were then applied as i-layers for p-i-n single junction solar cells. The current-voltage （I - V） characteristics of the cells were measured before and after the light soaking. The results suggest that the films deposited near the transition region have an optimum properties for application in solar cells. The cell with an i-layer prepared near the transition region shows the best stable performance.

Microstructure Analysis and Properties of Anti-Reflection Thin Films for Spherical Silicon Solar Cells

Structure and properties of anti-reflection thin films of spherical silicon solar cells were investigated and discussed. Conversion efficiencies of spherical Si solar cells coated with F-doped SnO2 anti-reflection films were improved by annealing. Optical absorption and fluorescence of the solar cells increased after annealing. Lattice constants of F-doped SnO2 anti-reflection layers, which were investigated by X-ray diffraction, decreased after annealing. A mechanism of atomic diffusion of F in SnO2 was discussed. The present work indicated a guideline for spherical silicon solar cells with higher efficiencies.

Reduction Bending of Thin Crystalline Silicon Solar Cells

Reported are the results of reduction the bending of thin crystalline silicon solar cells after printing and sintering of back electrode by changing the back electrode paste and adjusting the screen printing parameters without effecting the electrical properties of the cell.Theory and experiments showed that the bending of the cell is changed with its thickness of substrate,the thinner cell,the more serious bending.The bending of the cell is decreased with the thickness decrease of the back contact paste.The substrate with the thickness of 190 μm printing with sheet aluminum paste shows a relatively lower bend compared with that of the substrate printing with ordinary aluminum paste,and the minimum bend is 0.55 mm which is reduced by 52%.

Investigation on Silicon Thin Film Solar Cells

The preparation, current status and trends are investigated for silicon thin film solar cells. The advantages and disadvantages of amorphous silicon thin film, polycrystalline silicon thin film and mono-crystalline silicon thin film solar cells are compared. The future development trends are pointed out. It is found that polycrystalline silicon thin film solar cells will be more promising for application with great potential.

Enhanced Photovoltaic Properties for Rear Passivated Crystalline Silicon Solar Cells by Fabricating Boron Doped Local Back Surface Field

In order to enhance the p-type doping concentration in the LBSF, boron was added into the aluminum paste and boron doped local back surface field（B-LBSF） was successfully fabricated in this work. Through boron doping in the LBSF, much higher doping concentration was observed for the B-LBSF over the Al-LBSF. Higher doping concentration in the LBSF is expected to lead to better rear passivation and lower rear contact resistance. Based on one thousand pieces of solar cells for each type, it was found that the rear passivated crystalline silicon solar cells with B-LBSF showed statistical improvement in their photovoltaic properties over those with Al-LBSF.

Effect of emitter layer doping concentration on the performance of a silicon thin film heterojunction solar cell

A novel type of n/i/i/p heterojunction solar cell with a-Si：H（15 nm）/a-Si：H（10 nm）/epitaxial c-Si（47 p.m）/epitaxial c-Si（3 um） structure is fabricated by using the layer transfer technique, and the emitter layer is deposited by hot wire chemical vapour deposition. The effect of the doping concentration of the emitter layer Sd （Sd=PH3/（PH3 ＋SiH4＋H2）） on the performance of the solar cell is studied by means of current density-voltage and external quantum efficiency. The results show that the conversion efficiency of the solar cell first increases to a maximum value and then decreases with Sd increasing from 0.1% to 0.4%. The best performance of the solar cell is obtained at Sd = 0.2% with an open circuit voltage of 534 mV, a short circuit current density of 23.35 mA/cm2, a fill factor of 63.3%, and a conversion efficiency of 7.9%.

Surface morphology and impurity distribution of electron beam recrystallized silicon films on low cost substrates for solar cell absorber

A line shaped electron beam recrystallised polycrystalline silicon film on the low cost substrate was investigated for the use of the solar cell absorber. The applied EB energy density strongly influences the surface morphology of the film system. Lower EB energy density results in droplet morphology and the rougher SiO2 capping layer due to the low fluidity. With the energy increasing, the capping layer becomes smooth and continuous and less and small pinholes form in the silicon film. Tungstendisilicide (WSi2) is formed at the interface tungsten/silicon but also at the grain boundaries of the silicon. Because of the fast melting and cooling of the silicon film, the eutectic of silicon and tungstendisilicide mainly forms at the grain boundary of the primary silicon dendrites. The SEM-EDX analysis shows that there are no chlorine and hydrogen in the area surrounding a pinhole after recrystallization because of outgassing during the solidification.

Effects of deposition pressure and plasma power on the growth and properties of boron-doped microcrystalline silicon films

Using diborane as doping gas, p-doped μc-Si：H layers are deposited by using the plasma enhanced chemical vapour deposition （PECVD） technology. The effects of deposition pressure and plasma power on the growth and the properties of μc-Si：H layers are investigated. The results show that the deposition rate, the electrical and the structural properties are all strongly dependent on deposition pressure and plasma power. Boron-doped μc-Si：H films with a dark conductivity as high as 1.42 Ω^-1·cm^-1 and a crystallinity of above 50% are obtained. With this p-layer, μc-Si：H solar cells are fabricated. In addition, the mechanism for the effects of deposition pressure and plasma power on the growth and the properties of boron-doped μc-Si：H layers is discussed.

Emitter layer optimization in heterojunction bifacial silicon solar cells

Silicon solar cells continue to dominate the market,due to the abundance of silicon and their acceptable efficiency.The heterojunction with intrinsic thin layer(HIT)structure is now the dominant technology.Increasing the efficiency of these cells could expand the development choices for HIT solar cells.We presented a detailed investigation of the emitter a-Si:H(n)lay-er of a p-type bifacial HIT solar cell in terms of characteristic parameters which include layer doping concentration,thickness,band gap width,electron affinity,hole mobility,and so on.Solar cell composition:(ZnO/nc-Si:H(n)/a-Si:H(i)/c-Si(p)/a-Si:H(i)/nc-Si:H(p)/ZnO).The results reveal optimal values for the investigated parameters,for which the highest computed efficiency is 26.45%when lighted from the top only and 21.21%when illuminated from the back only.

Simulations of Heterojunction and Tandem Solar Cells Based on 3C Silicon Carbide

In order to improve the efficiency of solar cells based on cubic silicon carbide (3C-SiC), one heterojunction solar cell and two tandem structures were simulated under AM1.5 illumination using SCAPS software. The cells’ performances were studied according to the thickness of the silicon carbide layers. Simulation results allowed to achieve an efficiency of 22.03% with a tandem junction structure using an optimal thickness of 3C-SiC layer.

Silicon Film Fabrication by Liquid Phase Epitaxy at Low Temperature

ＳｉｌｉｃｏｎＦｉｌｍＦａｂｒｉｃａｔｉｏｎｂｙＬｉｑｕｉｄＰｈａｓｅＥｐｉｔａｘｙａｔＬｏｗＴｅｍｐｅｒａｔｕｒｅ①ＱＩＡＮＹｏｎｇｂｉａｏ，ＳＨＩＷｅｉｍｉｎ，ＣＨＥＮＰｅｉｆｅｎｇ，ＭＩＮＪｉａｈｕａ，ＧＵＹｏｎｇｍｉｎｇ，ＧＵＯＹａｎｍｉｎｇ...

Fabrication of Poly-Si Thin Film on Glass Substrate by Aluminum-induced Crystallization

Amorphous silicon （ a-Si ） thin films were deposited on glass substrate by PECVD, and polycrystalline silicon （ poly- Si ） thin films were prepared by aluminum- induced crystallization （ AlC ）. The effects of annealing temperature on the microstructure and morphology were investigated. The AlC poly-Si thin films were characterized by XRD, Raman and SEM. It is found that a-Si thin film has a amorphous structure after annealing at 400℃ for 20 min, a-Si films begin to crystallize after annealing at 450 ℃ for 20 min, and the crystallinity of a-Si thin films is enhanced obviously with the increment of annealing termperature.

Development of metal-recycling technology in waste crystalline-silicon solar cells

Solar energy is currently one of the most promising clean energy sources and the use of solar energy has led to a rapid increase in the number of solar cells.As one of the fastest-growing electronic wastes,the resource treatment of solar cells at the end of their life should not be neglected.This review discusses the trend for the market development of crystalline-silicon solar cells and analyzes their physical structure and composition.It also discusses the current domestic and international recycling technologies for crystalline-silicon solar cells,including manual dismantling,inorganic acid dissolution,the combination of heat-treatment and chemical methods,and organic solvent dissolution.The shortcomings of the above treatment methods are discussed and some views on the recycling of waste crystalline-silicon solar cells are presented.Constructive suggestions for the green and sustainable development of crystalline-silicon solar cells are put forward by comparing different treatment-recycling processes.

n-nc-Si:H低温制备工艺及其在柔性钙钛矿太阳电池中的应用

【目的】为在低温工艺下制备出适用于柔性钙钛矿太阳电池的高性能电子传输层,需要对电子传输层材料及制备条件进行研究。【方法】将n型氢化纳米晶硅薄膜作为柔性钙钛矿太阳电池电子传输层,研究衬底温度对薄膜性能的影响,并优化电子传输层与钙钛矿层界面处理工艺和结构。【结果】得到暗电导率、光透过率、表面形貌适用于柔性钙钛矿太阳电池电子传输层的n型氢化纳米晶硅薄膜低温制备条件,经过界面优化处理的柔性钙钛矿太阳电池转换效率达到14.66%。【结论】在低温工艺下制备出了高性能的电子传输层及柔性钙钛矿太阳电池,对进一步开展叠层钙钛矿太阳电池的研究具有指导意义。

Study on device simulation and performance optimization of the epitaxial crystalline silicon thin film solar cell

Because crystalline silicon thin film(CSiTF) solar cells possess the advantages of crystalline silicon solar cells such as high efficiency and stable performance and those of thin film solar cells such as low cost and so on,it is regarded as the next generation solar cell technology,which is most likely to replace the existing crystalline silicon solar cell technology.In this paper,we performed device simulation on the epitaxial CSiTF solar cell by using PC1D software.In order to make simulation results closer to the actual situation,we adopted a more realistic device structure and parameters.On this basis,we comprehensively and systematically investigated the effect of physical parameters of back surface field(BSF) layer,base and emitter,electrical quality of crystalline silicon active layer,situation of surface passivation,internal recombination and p-n junction leakage on the optoelectronic performance of the epitaxial CSiTF solar cell.Among various factors affecting the efficiency of the epitaxial CSiTF solar cell,we identified the three largest efficiency-affecting parameters.They are the base minority carrier diffusion length,the diode dark saturation current and the front surface recombination velocity in order.Through simulations,we found that the base is not the thicker the better,and the base minority carrier diffusion length must be taken into account when determining the optimal base thickness.When the base minority carrier diffusion length is smaller,the optimal base thickness should be less than or equal to the base minority carrier diffusion length;when the base minority carrier diffusion length is larger,the base minority carrier diffusion length should be at least twice the optimal base thickness.In addition,this paper not only illustrates the simulation results but also explains their changes from the aspect of physical mechanisms.Because epitaxial CSiTF solar cells possess a device structure that is similar to crystalline silicon solar cells,the conclusions drawn in this paper are also applied to crystalline silicon solar cells to a certain extent,particularly to thin silicon solar cells which are the hottest research topic at present.

晶硅太阳能电池制备过程中硅渣和金刚石线切割硅废料的回收利用研究进展

随着晶硅太阳能电池的快速发展,晶体硅片的需求大幅增加。晶体硅片在生产制备过程中,大量的硅以硅渣和金刚石线切割硅废料的形式流失。硅渣和金刚石线切割硅废料中硅的回收再循环利用对降低晶硅太阳能电池的成产成本、有效解决晶体硅片短缺以及环境污染等问题具有重要意义。本文通过对从硅渣和金刚石线切割硅废料中回收制备高纯硅的现有工艺和研究进展进行综述,对不同回收工艺的优势、缺陷以及改进措施进行分析,有助于研究人员选择合理的高纯硅回收策略,为晶硅太阳能电池产业的低成本、绿色可持续发展提供参考。

p-a-SiC:H降低晶体硅异质结太阳能电池寄生损失的研究

使用宽带隙的p型氢化非晶硅碳(p-a-SiC:H)薄膜作为晶体硅异质结(SHJ)太阳能电池的窗口层,使用时域有限差分法(FDTD)模拟证明,p-a-SiC:H不仅能明显降低窗口层的短波寄生吸收损失,而且可以减少SHJ太阳能电池的反射损失,从而增强SHJ太阳能电池的光谱响应。实验结果也证明,使用优化的p-a-SiC:H窗口层可以提升SHJ太阳能电池的短路电流(J_(sc))达1.4 mA/cm^(2),电池光电转化效率达到了21.8%。这主要是由于p-a-SiC:H低的寄生吸收以及使用p-a-SiC:H窗口层降低了SHJ太阳能电池的反射损失所致。