Challenges and prospects for developing CdS/CdTe substrate solar cells on Mo foils
Challenges and prospects for developing CdS/CdTe substrate solar cells on Mo foils
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DOI：
10.1016/j.solmat.2014.01.017
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发表时间：
2014-05-01
影响因子：
6.9
通讯作者：
Durose, K.
中科院分区：
文献类型：
--
作者：
Williams, B. L.;Major, J. D.;Durose, K.
采用近空间升华和射频溅射相结合的方法在衬底上生长了ITO/ZnO/CdS/CdTe/Mo太阳电池。最高效率为8.01%。一个两阶段的氯化镉退火过程中，第一阶段的CdTe掺杂和第二被链接到CdTe/CdS相互扩散的二次离子质谱分析。通过将分流电阻R-SH从563 0 cm（2）增加到881 Ω cm 2，在CdS和ITO层之间包括ZnO层显著地改善了性能（从17=6%到q=8%）。横截面扫描电子显微镜突出了电阻ZnO层的重要性，因为在CdS膜中存在许多针孔和空隙。太阳能电池的性能也被研究作为CdTe厚度的函数，最佳厚度在3-6 μ m的范围内。所有器件被认为主要受非欧姆背接触的限制，肖特基势垒高度通过温度依赖性J-V测量确定为0.51 eV。使用SCAPS预测的高达11.3%的效率的器件性能的建模可以在欧姆背接触形成时获得。SCAPS模型还表明，准欧姆背接触可以通过在CdTe和Mo之间包含高度p掺杂（类似于10（18）cm（-3））的缓冲层来实现，该缓冲层也具有最佳电子亲和力（4.2 eV）。器件工艺的评估和深入的表征提供了对基板电池性能的持续改进的一些见解。(C)2014作者由爱思唯尔公司出版
ITO/ZnO/CdS/CdTe/Mo solar cells have been grown in the substrate configuration by a combination of close-space sublimation and RF sputtering. A peak efficiency of 8.01% was achieved. A two stage CdCl2 annealing process was developed, with the first stage contributing to CdTe doping and the second being linked to CdTe/CdS interdiffusion by secondary ion mass spectrometry analysis. The inclusion of a ZnO layer between CdS and ITO layers improved performance significantly (from 17=6% to q=8%) by increasing the shunt resistance, R-SH, from 563 0 cm(2) to 881 Omega cm2. Cross-sectional scanning electron microscopy highlighted the importance of the resistive ZnO layer as numerous pinholes and voids exist in the CdS film. Solar cell performance was also investigated as a function of CdTe thickness, with optimal thicknesses being in the range 3-6 mu m. All devices were deemed to be limited principally by a non-Ohmic back contact, the Schottky barrier height being determined to be 0.51 eV by temperature dependent J-V measurements. Modelling of device performance using SCAPS predicted efficiencies as high as 11.3% may be obtainable upon formation of an Ohmic back-contact. SCAPS modelling also demonstrated that a quasi-Ohmic back-contact may be achievable via inclusion of a highly p-doped (similar to 10(18) cm(-3)) buffer layer, between CdTe and Mo, which also has an optimal electron affinity (4.2 eV). The evaluation of device processing and the in-depth characterisation presented here provides a number of insights towards the continued improvement of substrate cell performance. (C) 2014 The Authors. Published by Elsevier B.V.