磁控溅射制备Cu2ZnSnS4薄膜的研究进展

Cu_2ZnSnS_4(CZTS)薄膜由于其合适的禁带宽度、高的光吸收系数以及组分无毒、储量丰富等特性,被视为薄膜太阳能电池最佳的吸收层材料之一。磁控溅射是制备CZTS薄膜的主要方法之一,因为其制备过程相对简单且可以产业化,一直是太阳能电池领域的研究热点。从磁控溅射制备CZTS薄膜的3种路径出发,综述了近年来各种路径在制备CZTS薄膜方面的研究进展,比较了3种路径的优缺点,同时对磁控溅射制备CZTS薄膜的发展前景进行了展望。     

新型铜硫系薄膜太阳能电池材料制备的研究进展

薄膜太阳能电池提供了低成本、大面积的无碳发电应用前景,迅猛发展的纳米科技为高转换效率薄膜太阳能电池的低成本制造提供了新途径。新型铜硫系半导体Cu_2ZnSnS_4(CZTS)薄膜材料具有禁带宽度与太阳辐射匹配性好、光吸收系数大、元素丰度大、价格便宜、无毒等优点,因此将成为最具发展前景的薄膜太阳能电池材料。讨论与分析了CZTS薄膜和纳米晶材料的制备及由这些材料制备绿色、低成本、高效率新型太阳能电池的研究进展。     

电沉积法制备铜锌锡硫薄膜太阳能电池吸收层的研究进展

直接禁带半导体材料铜锌锡硫(CZTS)四元硫化物是近年来研究较多的具有锌黄锡矿结构的化合物半导体,由于其光吸收系数较高,禁带宽度适中,是太阳能电池理想的候选材料,使其在薄膜太阳能电池中迅速崛起。由于目前报道的最高转换效率距离其理论转换效率还存在相当差距,因此,研究CZTS(Se)四元硫(硒)化物半导体仍然是当前的研究热点之一。简单介绍了CZTS薄膜太阳能电池的结构组成,并详细介绍了3种主要制备CZTS薄膜的电沉积方法,即分步沉积Cu/Sn/Zn金属层、连续沉积Cu-Zn-Sn金属层、一步沉积Cu-Zn-Sn-S(Se)制备CZTS薄膜太阳能电池吸收层的电化学技术及相应器件,对其研究进展进行了综述,指出了相应方法存在的问题。还将3种电沉积方法进行了分析比较,提出了优化方法,展望了未来的发展趋势。     

溶胶-凝胶法制备铜锌锡硫材料的研究进展

四元硫化物铜锌锡硫(CZTS)是一种新型薄膜太阳电池材料,具有锌黄锡矿结构,呈p型导电性,带隙约为1.5eV,光学吸收系数高于10~4cm~(-1),这些特性与太阳光谱相匹配。基于上述原因,CZTS薄膜是一种有望能低成本、可规模化开发利用的新型薄膜太阳电池材料。简要阐述了CZTS性质及其薄膜太阳能电池的器件结构,详细介绍了溶胶-凝胶方法制备CZTS薄膜及其相应器件效率的研究进展。最后,总结了此方法制备CZTS薄膜及其相关电池性能难以突破的关键技术问题,并提出了有效的改进措施,对CZTS薄膜太阳电池未来的研究进行了展望。     

新型铜硫系薄膜太阳能电池材料制备的研究进展

薄膜太阳能电池提供了低成本、大面积的无碳发电应用前景，迅猛发展的纳米科技为高转换效率薄膜太阳能电池的低成本制造提供了新途径。新型铜硫系半导体Cu。ZnSnS4（CZTS）薄膜材料具有禁带宽度与太阳辐射匹配性好、光吸收系数大、元素丰度大、价格便宜、无毒等优点，因此将成为最具发展前景的薄膜太阳能电池材料。讨论与分析了CZT...     

CZTS薄膜太阳能电池无镉缓冲层材料的研究进展

Cu(In,Ga) Se_2(CIGS)薄膜太阳能电池是单结转换效率最高(～22. 6%)的光伏器件,但In、Ga是稀缺元素,从而限制了CIGS电池的产业化。新型材料Cu_2ZnSnS_4(CZTS)是结构与光电性能均与CIGS十分相似的直接带隙半导体材料,它在CIGS器件结构中可替代CIGS吸收层,并得到新型CZTS薄膜太阳能电池。与CIGS相反,CZTS的原料丰富、无毒。大量研究表明,CZTS薄膜太阳能电池具有较高的转换效率和良好的稳定性,且可采用低成本、非真空的溶液法薄膜沉积技术来制造,因此CZTS器件是一种低成本、环境友好、极具产业化前景的薄膜太阳能电池。CZTS器件具有与CIGS器件一样的堆层结构{SLG/Mo/CZTS/CdS/i-ZnO/n-ZnO},目前转换效率最高(～12. 6%)的CZTS器件仍沿用CIGS器件的CdS缓冲层,因而大规模生产与应用中存在高毒重金属镉污染的危险,寻找能替代CdS的无镉缓冲层材料来消除潜在的镉污染问题十分必要。此外,与高效率的{CIGS/CdS}器件相比,{CZTS/CdS}器件界面的能带匹配可能并不是最优,CZTS器件的转换效率还远不如CIGS器件,因此需要寻找新的无镉缓冲层材料。在确定新缓冲层材料时,必须考虑{CZTS/新缓冲层}界面的能级对齐效应。CIGS和CZTS器件的缓冲层新材料基本上可归纳为3种半导体材料:硫化物、硫氧化物、氧化物。这些材料的薄膜均可用化学浴(CBD)法等多种方法来制备。材料选取很大程度上取决于其与CZTS或CIGS吸收层接触所形成界面上的导带带阶情况,因为导带带阶对器件性能参数有很大的影响。大的正导带带阶(尖刺状带阶)对少子(电子)收集存在一个势垒而降低短路电流密度J_(sc);相反,负导带带阶(断崖状带阶)导致缓冲层与吸收层界面上的复合增大而降低了开路电压V_(oc);理想情况是器件有一个小(0～0. 4 eV)的正导带带阶(尖刺状带阶),正如在使用CdS缓冲层的CIGSSe器件中所发现的那样。为了研发低成本、环境友好的CZTS电池器件的新型缓冲层材料,本文综述了CZTS和CIGS器件的无镉缓冲层材料的研究进展,讨论了无镉缓冲层材料的选用条件,以及多种硫化物(如ZnS和In_2S_3)、硫氧化物(如Zn(S,O)和In(S,O,OH))、氧化物(如ZnO、TiO_2、Zn_(1-x)Mg_xO_y和Zn_(1-x)Sn_xO_y等)薄膜作为CZTS缓冲层的性能特点(特别是它们的导带带阶)以及存在的问题,探讨了其发展方向。对于含硒CZTSSe器件,In2S3、Zn(S,O)是良好的无镉缓冲层材料,而对于更环保、低成本的全硫CZTS器件,Zn_(1-x)Mg_xO_y和Zn_(1-x)Sn_xO_y可提供良好性能的缓冲层。     

溶胶-凝胶法制备铜锌锡硫薄膜及其太阳能电池的研究进展

原料丰富价廉的铜锌锡硫(Cu2ZnSnS4,CZTS)材料与非真空、低成本绿色溶胶-凝胶法相结合在产业化制造高性价比CZTS薄膜太阳能电池方面的应用引人关注。为了了解未来发展方向,综述了溶胶-凝胶法制备CZTS薄膜与器件的研究进展,讨论了不同溶胶-凝胶工艺途径、不同溶剂、硫化等对CZTS薄膜制备与器件特性的影响,分析了Na掺杂及硫化退火对CZTS薄膜的作用,并结合绿色制造的要求探讨了其发展趋势。     

阳离子掺杂措施优化铜锌锡硫硒电池性能的研究进展

铜锌锡硫硒(Cu₂ZnSn(S,Se)₄,简称CZTSSe)薄膜太阳能电池因其组成元素地壳含量丰富，低毒环保等优点被科学家们认为是适合未来大面积发展的一类太阳能电池。当前，该类太阳能电池的效率一直受到吸收层中高的阳离子无序度和器件的低开路电压的限制。为此，科学家们提出“阳离子掺杂措施”,即：通过引入其他阳离子，减少本身的阳离子无序度，从而提高电池器件的光电转换效率。事实也证明，阳离子掺杂措施在提升电池器件性能方面有着重大的意义。基于此，详细阐述了阳离子掺杂措施在优化铜锌锡硫硒电池器件性能方面的研究进展，包括：阳离子(如：钠、钾、锑)的额外添加和阳离子取代(如：锂/银取代铜、锰/镁/钡/镉取代锌、锗取代锡)措施，并得出结论：最有前景的阳离子是镉和锗离子，考虑到镉的有毒性，所以锗应该是优化CZTSSe电池性能方面最有应用前景的一种元素。     

Cu_2ZnSnS_4薄膜的研究进展

Cu2ZnSnS4(CZTS)薄膜太阳能电池具有低成本、高效率、安全无毒等优点,是最具发展前景的太阳能电池之一,近几年来开始受到广泛关注。简要介绍了国内外几种制备Cu2ZnSnS4薄膜的方法,包括蒸发法、溅射法、脉冲激光沉积法、电化学沉积法、喷涂热解法、Sol-gel法、丝网印刷法,并阐述了这几种方法的优点及存在的问题,展望了今后CZTS薄膜的研究方向,认为通过溶剂热或热注入法制备出CZTS纳米晶体后,再通过丝网印刷法或旋涂等法制成CZTS薄膜能降低生产成本,在电池的工业化生产中具有很广阔的应用前景。     

SiGe∶H薄膜太阳能电池研究进展

针对氢化非晶硅(a-Si∶H)薄膜太阳能电池在发展过程中所面临的问题,阐述了氢化硅锗(SiGe∶H)薄膜在太阳能电池制备方面的优越性及其最新研究进展,总结了提高SiGe∶H薄膜太阳能电池效率的几种方法,着重介绍了叠层太阳能电池内部运行机理,分析了影响叠层太阳能电池转换效率的因素,最后对SiGe∶H薄膜材料在太阳能电池领域的应用前景以及一些亟待解决的问题进行了展望。     

Preparation of Cu2ZnSnS4 thin films by sulfurization of stacked metallic layers

Stacked precursors of Cu, Sn, and Zn were fabricated on glass/Mo substrates by electron beam evaporation. Six kinds of precursors with different stacking sequences were prepared by sequential evaporation of Cu, Sn, and Zn with substrate heating. The precursors were sulfurized at temperatures of 560 °C for 2 h in an atmosphere of N₂ + sulfur vapor to fabricate Cu₂ZnSnS₄ (CZTS) thin films for solar cells. The sulfurized films exhibited X-ray diffraction peaks attributable to CZTS. Solar cells using CZTS thin films prepared from six kinds of precursors were fabricated. As a result, the solar cell using a CZTS thin film produced by sulfurization of the Mo/Zn/Cu/Sn precursor exhibited an open-circuit voltage of 478 mV, a short-circuit current of 9.78 mA/cm², a fill factor of 0.38, and a conversion efficiency of 1.79%.     

Cu2ZnSnS4 thin film solar cells from electroplated precursors: Novel low-cost perspective

Thin-film solar cells based on Cu₂ZnSnS₄ (CZTS) absorbers were fabricated successfully by solid-state reaction in H₂S atmosphere of electrodeposited Cu-Zn-Sn precursors. These ternary alloys were deposited in one step from a cyanide-free alkaline electrolyte containing Cu(II), Zn(II) and Sn(IV) metal salts on Mo-coated glass substrates. The solar cell was completed by a chemical bath-deposited CdS buffer layer and a sputtered i-ZnO/ZnO:Al bilayer. The best solar cell performance was obtained with Cu-poor samples. A total area (0.5 cm²) efficiency of 3.4% is achieved (V_oc = 563 mV, j_sc = 14.8 mA/cm², FF = 41%) with a maximum external quantum efficiency (EQE) of 80%. The estimated band-gap energy from the external quantum efficiency (EQE) measurements is about 1.54 eV. Electron backscatter-diffraction maps of cross-section samples revealed CZTS grain sizes of up to 10 µm. Elemental distribution maps of the CZTS absorber show Zn-rich precipitates, probably ZnS, and a Zn-poor region, presumably Cu₂SnS₃, close to the interface Mo/CZTS.     

Cu2ZnSnS4 solar cells prepared with sulphurized dc-sputtered stacked metallic precursors

In the present work we report the details of the preparation and characterization results of Cu₂ZnSnS₄ (CZTS) based solar cells. The CZTS absorber was obtained by sulphurization of dc magnetron sputtered Zn/Sn/Cu precursor layers. The morphology, composition and structure of the absorber layer were studied by scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction and Raman scattering. The majority carrier type was identified via a hot point probe analysis. The hole density, space charge region width and band gap energy were estimated from the external quantum efficiency measurements. A MoS₂ layer that formed during the sulphurization process was also identified and analyzed in this work. The solar cells had the following structure: soda lime glass/Mo/CZTS/CdS/i-ZnO/ZnO:Al/Al grid. The best solar cell showed an open-circuit voltage of 345 mV, a short-circuit current density of 4.42 mA/cm², a fill factor of 44.29% and an efficiency of 0.68% under illumination in simulated standard test conditions: AM 1.5 and 100 mW/cm².     

Cu2ZnSnS4 solar cell prepared entirely by non-vacuum processes

Cu₂ZnSnS₄ (CZTS) solar cell with superstrate structure of fluorine-doped tin oxide glass/TiO₂/In₂S₃/CZTS/Carbon was prepared entirely by non-vacuum processes. The compact TiO₂ window and In₂S₃ buffer layers, CZTS absorber layer and Carbon electrode layer were prepared by spray pyrolysis method, ball milling and screen printing combination processes and screen printing process, respectively. The short-circuit current density, open-circuit voltage, fill factor and conversion efficiency of the best fabricated solar cell are 8.76 mA/cm², 250 mV, 0.27 and 0.6%, respectively. The fabrication process for the CZTS solar cell did not employ any vacuum conditions or high-toxic materials (such as CdS, H₂Se, H₂S or Se).     

Sphere-like kesterite Cu2ZnSnS4 nanoparticles synthesized by a facile solvothermal method

In this paper, sphere-like kesterite Cu₂ZnSnS₄ (CZTS) nanoparticles were successfully synthesized by a facile solvothermal method. The CZTS nanoparticles with diameter range of 100-150 nm were agglomerated by CZTS nanocrystals. The as-obtained CZTS nanoparticles were characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission election microscopy (TEM), Energy Dispersive Spectrometry (EDS) and UV-vis spectroscopy. Texture structures with kesterite crystallinity were reflected from the X-ray diffraction of 112, 200 and 312 planes of the CZTS nanoparticles. The UV-vis absorption spectra showed that CZTS nanoparticles had strong absorption in the visible light region. The observed band gap of 1.48 eV matched well with the bulk CZTS material that was optimal for solar cells.     

Development of CZTS-based thin film solar cells

The low cost, environmental harmless Cu₂ZnSnS₄ (CZTS)-based thin film solar cells are fabricated by using abundant materials. The CZTS film possesses promising characteristic optical properties; band-gap energy of about 1.5 eV and large absorption coefficient in the order of 10⁴ cm^− 1. All constituents of this CZTS film, which are abundant in the crust of the earth, are non-toxic. Therefore, if we can use CZTS film practically as the absorber of solar cells, we will be free from both of the resource saving problem and the environmental pollution.In our CZTS project, CZTS absorber films were prepared by two independent techniques. One is three rf sources co-sputtering followed by annealing in sulfurized atmosphere. The latest conversion efficiency of over 6.7% was achieved by this technique. The other is co-evaporation technique. CZTS films were grown on Si (100) by vacuum co-evaporation using elemental Cu, Sn, S and binary ZnS as sources. XRD patterns indicated that the polycrystalline growth was suppressed and the orientational growth was relatively induced in a film grown at higher temperatures.In this presentation, the development of CZTS-based thin film solar cells will be surveyed.     

Characterisation of ultrasonically sprayed InxSy buffer layers for Cu(In,Ga)Se2 solar cells

In order to replace chemical bath deposited (CBD) CdS buffer layers in Cu(In,Ga)Se₂ (CIGS) solar cells by an alternative material, In_xS_y thin-film buffer layers were prepared by ultrasonic spray pyrolysis at various substrate temperatures. X-ray Diffraction measurements confirmed that the films contained primarily the tetragonal In₂S₃ phase. X-ray Photoelectron Spectroscopy measurements revealed a small concentration of chlorine impurity throughout the In_xS_y layer. By depositing the indium sulphide layer as buffer layer in the CIGS solar cell configuration, a maximum solar cell efficiency of 8.9% was achieved, whilst the reference cell with CdS/CIGS on a similar absorber exhibited 12.7% efficiency. Additionally, light soaking enhanced the efficiency of In_xS_y/CIGS cells primarily by improvements in fill factor and open circuit voltage.