期刊
SOLAR ENERGY MATERIALS AND SOLAR CELLS
卷 142, 期 -, 页码 42-46出版社
ELSEVIER SCIENCE BV
DOI: 10.1016/j.solmat.2015.05.032
关键词
Surface passivation; Tantalum oxide; Silicon nitride; Solar cells
资金
- Australian government through the Australian Renewable Energy Agency (ARENA)
- Trina Solar [2014/RND003]
We demonstrate effective passivation of a variety of crystalline silicon (c-Si) surfaces by thermal atomic layer deposited (ALD) tantalum oxide (Ta2O5) underneath a capping silicon nitride (SiNx) layer by plasma enhanced chemical vapor deposited (PECVD). Surface recombination is investigated as a function of Ta2O5 thickness for p- and n-type Si substrates, both with and without boron (p(+)) or phosphorus (n(+)) diffusions. It is found that the recombination decreases markedly with increasing Ta2O5 thickness on p, n and p(+) c-Si surfaces, but it follows an opposite trend on n(+) c-Si surfaces. In all four cases, the surface recombination velocity plateaus at a Ta2O5 thickness of 12 nm. The thermal stability of surface passivation by Ta2O5/SiNx is examined by subjecting p(+) and n(+) diffused wafers to a typical solar cell metallization firing process, finding that it is essentially stable on p(+) diffusions, but not on n(+) ones, regardless of Ta2O5 thickness. We also evaluate the passivating properties of the Ta2O5/SiNx stack on planar {100}, planar {111} and textured n-type undiffused silicon surfaces, finding that (i) planar {111} Si exhibits a 4.6-fold higher recombination than planar{100} Si, and (ii) recombination at a textured surface is approximately equivalent to that at a planar OM after surface area correction. Furthermore, the area-corrected recombination ratio of textured to planar {100} boron diffused p(+) regions is shown to be 2.2 for three different diffusions with sheet resistances at 56, 122, and 214 Omega/sq. Finally, optical simulation reveals a low reflection and negligible absorption loss for the Ta2O5/SiNx stack. The Ta2O5/SiNx stack is thus demonstrated to be an excellent surface passivation and antireflection coating for high efficiency silicon solar cells. (C) 2015 Elsevier B.V. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据