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Wang Y.,CAS Institute of Physics | Wang Y.,Chinese Academy of Sciences | Liu Y.P.,CAS Institute of Physics | Liu Y.P.,Chinese Academy of Sciences | And 10 more authors.
RSC Advances | Year: 2013

A nano-emitter is fabricated by one-step Ag-assisted chemical etch-back after conventional POCl3 diffusion, with the intention of overcoming the relatively low efficiency of black silicon solar cells. The conversion efficiency of the multicrystalline silicon nano-emitter solar cell with a suitable sheet resistance is significantly improved thanks to the increased open-circuit voltage, short current and fill factor, all arising from the reduced surface recombination and Auger recombination, as well as the improved ohmic contact. In order to further improve the performance of the solar cell, it is combined with the selective emitter technique, resulting in a multicrystalline silicon selective nano-emitter solar cell. The selective emitters-etched back for different sheet resistances-are investigated to optimize the conversion efficiency. A 16.94% conversion efficiency is finally achieved with a sheet resistance of 107 Ω sq-1, which is 0.34% higher than a standard selective emitter solar cell. Such an improved efficiency can be attributed to a lower reflectivity, a more homogeneous emitter, a smaller surface area and Auger recombination. © The Royal Society of Chemistry 2013.


Liu Y.,CAS Institute of Physics | Lai T.,Tianwei New Energy Holdings Co. | Li H.,CAS Institute of Electrical Engineering | Wang Y.,CAS Institute of Physics | And 7 more authors.
Small | Year: 2012

Nanoscale textured silicon and its passivation are explored by simple low-cost metal-assisted chemical etching and thermal oxidation, and large-area black silicon was fabricated both on single-crystalline Si and multicrystalline Si for solar cell applications. When the Si surface was etched by HF/AgNO 3 solution for 4 or 5 min, nanopores formed in the Si surface, 50-100 nm in diameter and 200-300 nm deep. The nanoscale textured silicon surface turns into an effective medium with a gradually varying refractive index, which leads to the low reflectivity and black appearance of the samples. Mean reflectance was reduced to as low as 2% for crystalline Si and 4% for multicrystalline Si from 300 to 1000 nm, with no antireflective (AR) coating. A black-etched multicrystalline-Si of 156 mm × 156 mm was used to fabricate a primary solar cell with no surface passivation or AR coating. Its conversion efficiency (ν) was 11.5%. The cell conversion efficiency was increased greatly by using surface passivation process, which proved very useful in suppressing excess carrier recombination on the nanostructured surface. Finally, a black m-Si cell with efficiency of 15.8% was achieved by using SiO 2 and SiNX bilayer passivation structure, indicating that passivation plays a key role in large-scale manufacture of black silicon solar cells. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Jiang L.-L.,Southwest Jiaotong University | Jiang L.-L.,TianWei New Energy Holdings CO. | Lu Z.-L.,TianWei New Energy Holdings CO. | Zhang F.-M.,TianWei New Energy Holdings CO. | Lu X.,Southwest Jiaotong University
Wuli Xuebao/Acta Physica Sinica | Year: 2013

A new low-temperature annealing phosphorous gettering process (LTAPGP) was developed to improve the electrical properties of multi-crystalline silicon which has a low minority carrier lifetime. LTAPGP combined a multi-plateau temperature phosphorous gettering process and a low-temperature annealing process. LTAPGP can remove the iron impurities and crystallographic defects of multi-crystalline silicon, and improve the electrical properties of silicon solar cells that were produced from low minority carrier lifetime silicon wafers. Compared with multi-plateau and two-plateau temperature phosphorous gettering process, LTAPGP was more effective in gettering iron impurities and repairing crystallographic defects. The multi-crystalline silicon wafers with a low minority carrier lifetime went through an LTAPGP process were utilized to produce solar cells. The IV-measurement data prove that the efficiency of the new solar cells is 0.2% higher than that of specimens subject to the multi-plateau and two-plateau temperature processes. The results indicat that LTAPGP can make the low minority carrier lifetime silicon wafers to be used in solar cell industry, improve the utilization ratio and reduce the production cost of cast polysilicon. © 2013 Chinese Physical Society.


Wang L.,Tianwei New Energy Holdings Co. | Long W.,Tianwei New Energy Holdings Co. | Gao Q.,Tianwei New Energy Holdings Co. | Wu J.,Tianwei New Energy Holdings Co. | And 2 more authors.
ECS Transactions | Year: 2014

Efficiency degradation of crystalline silicon solar cells is known as a general phenomena in the photovoltaic (PV) applications. Degradation sometimes could be significant to result in failure of PV systems. It is presented in this work that electrical properties of multi-crystalline silicon solar cells(multi cells) degrade under different ambiences, temperatures, humidities and illumination conditions etc. Periodical measurements were taken to demonstrate such trends in detail using various wafer materials. Degradation mechanisims are also discussed in this work, combined with the valid methods to reduce the degradation of multi cells based on current raw materials, equipments and processing technologies. © 2014 The Electrochemical Society.


Wu Z.,University of Electronic Science and Technology of China | Liu X.C.,University of Electronic Science and Technology of China | Liu X.C.,Tianwei New Energy Holdings Co. | Liu X.C.,National Cheng Kung University | Huang J.C.A.,National Cheng Kung University
Journal of Magnetism and Magnetic Materials | Year: 2012

Nanocrystalline Tb doped ZnO films have been prepared by ion-beam sputtering technology. Magnetic property shows that the films are ferromagnetic and the Curie Temperature (Tc) is over room temperature. Structure property investigation indicates that no secondary phase is found in all the films, which suggests that the ferromagnetism is caused by the incorporation of Tb into ZnO lattice. The saturation magnetization of the films are about 0.38 μb/Tb. Electrical property investigation proves that the carriers of the films are strongly localized, which suggests that the ferromagnetism in the film may be caused by the defects in the films. © 2011 PublishedbyElsevier B.V.


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Trademark
Tianwei New Energy Holdings Co. | Date: 2011-04-12

Electric cables, wires, conductors and connection fittings therefor; Electric switches; Electric voltage transformers; Inverters; Photovoltaic cells; Silicon wafers; Solar cells; Traffic-light apparatus.


Trademark
Tianwei New Energy Holdings Co. | Date: 2010-01-19

Electric cables, wires, conductors and connection fittings therefor; Electric switches; Electric voltage transformers; Inverters; Photovoltaic cells; Silicon wafers; Solar cells; Traffic-light apparatus.


T

Trademark
Tianwei New Energy Holdings Co. | Date: 2010-01-19

Electric cables, wires, conductors and connection fittings therefor; Electric switches; Electric voltage transformers; Inverters; Photovoltaic cells; Silicon wafers; Solar cells; Traffic-light apparatus.

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