Highly Arsenic Doped CdTe Layers for the Back Contacts of CdTe Solar Cells
Highly Arsenic Doped CdTe Layers for the Back Contacts of CdTe Solar Cells
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用于 CdTe 太阳能电池背接触的高砷掺杂 CdTe 层
DOI：
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发表时间：
2007
期刊：
影响因子：
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通讯作者：
D. Lamb
中科院分区：
文献类型：
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作者：
V. Barrioz;Y. Proskuryakov;Eurig W Jones;J. Major;S. Irvine;K. Durose;D. Lamb
为了解决缺乏合适的金属作为CdTe太阳电池欧姆背接触的问题，研究了将高砷(As)掺杂的CdTe层进行金属化的可能性。采用金属有机化学气相沉积(MOCVD)的方法，在不需要刻蚀的情况下，实现了包括高掺杂的CdTe：As和CdCl2处理在内的完整的CdTe/CDS器件的沉积。对它们进行了表征，并与传统的溴-甲醇背接触腐蚀制备的对照器件进行了比较。SIMS和C-V分析结果表明，在CdTe中掺入了高达1.5×1019at·cm-3的砷。电流-电压(J-V)特性有很大的改善，尤其是开路电压(VoC)和串联电阻(Rs)：在接触面积为0.25cm2时，串联电阻从9.8Ω·cm~2降至1.6Ω·cm~2；J-V曲线没有翻转，而VOC增加了70 mV(~12%)。初步的X射线衍射数据表明，在CdTe表面可能有一层As2Te3层，这可能是造成这种接触的低势垒高度的原因。
In an effort to overcome the lack of a suitable metal as an ohmic back contact for CdTe solar cells, a study was carried out on the potential for using a highly arsenic (As) doped CdTe layer with metallization. The deposition of full CdTe/CdS devices, including the highly doped CdTe:As and the CdCl2 treatment, were carried out by metal organic chemical vapour deposition (MOCVD), in an all-in-one process with no etching being necessary. They were characterized and compared to control devices prepared using conventional bromine-methanol back contact etching. SIMS and C-V profiling results indicated that arsenic concentrations of up to 1.5 × 1019 at·cm-3 were incorporated in the CdTe. Current-voltage (J-V) characteristics showed strong improvements, particularly in the open-circuit voltage (Voc) and series resistance (Rs): With a 250 nm thick doped layer, the series resistance was reduced from 9.8 Ω·cm2 to 1.6 Ω·cm2 for a contact area of 0.25 cm2; the J-V curves displayed no rollover, while the Voc increased by up to 70 mV (~ 12 % rise). Preliminary XRD data show that there may be an As2Te3 layer at the CdTe surface which could be contributing to the low barrier height of this contact.