Using silicon nanostructures for the improvement of silicon solar cells efficiency
Using silicon nanostructures for the improvement of silicon solar cells efficiency
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DOI：
10.1016/j.tsf.2005.12.008
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发表时间：
2006-07-26
期刊：
影响因子：
2.1
通讯作者：
Buffet, N.
中科院分区：
文献类型：
--
作者：
De la Torre, J.;Bremond, G.;Buffet, N.
由于量子限制效应导致带隙展宽，硅纳米结构 (ns-Si) 显示出有趣的光学和电学特性。除了它们在硅基光发射器制造中的潜在用途之外，它们还可以成为提高硅基太阳能电池能量转换效率的一个有吸引力的选择，无论是通过利用其发光特性（光子下转换）还是通过改进的高能光子吸收产生的过量光电流。在这项工作中，我们报告了含有硅纳米结构（ns-Si）的非化学计量二氧化硅（SiOx）和氮化硅（SiNx）层的形态和光学研究，考虑到它们在提高太阳能电池效率方面的应用。通过透射电子显微镜 (TEM) 对样品进行的形态研究明确表明，高温退火 SiOx 层和低温沉积 SiNx 层中存在晶体形式的 ns-Si。两种层的光致发光发射（PL）都显示出相当高的效率，其强度仅比多孔硅（pi-Si）低约100倍。光电流光谱 (PC) 显示高光子能量激发下的吸收显着增加，这很可能与 ns-Si 量子态内的光子吸收有关。此外，从PC光谱获得的吸收特性与PL发射态非常一致，明确地证明了与ns-Si内的Q限制激子相关的相同起源。最后，这种材料的主要优点是可以以微不足道的成本将其纳入太阳能电池制造过程中。 (c) 2005 Elsevier B.V. 保留所有权利。
Silicon nanostructures (ns-Si) show interesting optical and electrical properties as a result of the band gap widening caused by quantum confinement effects. Along with their potential utilization for silicon-based light emitters' fabrication, they could also represent an appealing option for the improvement of energy conversion efficiency in silicon-based solar cells whether by using their luminescence properties (photon down-conversion) or the excess photocurrent produced by an improved high-energy photon's absorption. In this work, we report on the morphological and optical studies of non-stoichiometric silica (SiOx) and silicon nitride (SiNx) layers containing silicon nanostructures (ns-Si) in view of their application for solar cell's efficiency improvement. The morphological studies of the samples performed by transmission electron microscopy (TEM) unambiguously show the presence of ns-Si in a crystalline form for high temperature-annealed SiOx layers and for low temperature deposition of SiNx layers. The photoluminescence emission (PL) shows a rather high efficiency in both kind of layers with an intensity of only a factor similar to 100 lower than that of porous silicon (pi-Si). The photocurrent spectroscopy (PC) shows a significant increase of absorption at high photon energy excitation most probably related to photon absorption within ns-Si quantized states. Moreover, the absorption characteristics obtained from PC spectra show a good agreement with the PL emission states unambiguously demonstrating a same origin, related to Q-confined excitons within ns-Si. Finally, the major asset of this material is the possibility to incorporate it to solar cells manufacturing processing for an insignificant cost. (c) 2005 Elsevier B.V. All rights reserved.