Sahraei Nasim, Peters Marius, Venkataraj Selvaraj, Aberle Armin G, Calnan Sonya, Ring Sven, Stannowski Bernd, Schlatmann Rutger, Stangl Rolf
Appl Opt. 2015 May 10;54(14):4366-73. doi: 10.1364/AO.54.004366.
Light scattering superstrates are important for thin-film a-Si:H solar cells. In this work, aluminum-induced texture (AIT) glass, covered with nonetched Al-doped ZnO (AZO), is investigated as an alternative to the commonly used planar glass with texture-etched AZO superstrate. Four different AIT glasses with different surface roughnesses and different lateral feature sizes are investigated for their effects on light trapping in a-Si:H solar cells. For comparison, two reference superstrates are investigated as well: planar glass covered with nonetched AZO and planar glass covered with texture-etched AZO. Single-junction a-Si:H solar cells are deposited onto each superstrate, and the scattering properties (haze and angular resolved scattering) as well as the solar cell characteristics (current-voltage and external quantum efficiency) are measured and compared. The results indicate that AIT glass superstrates with nonetched AZO provide similar, or even superior, light trapping than the standard reference superstrate, which is demonstrated by a higher short-circuit current Jsc and a higher external quantum efficiency. Using the trapped light fraction δ, a quantity based on the integrated light scattering at the AZO/a-Si:H interface, we show that Jsc linearly increases with δ in the scattering regime of the samples, regardless of the type of superstrate used.
光散射超基板对于薄膜非晶硅氢化太阳能电池很重要。在这项工作中，研究了覆盖有未蚀刻铝掺杂氧化锌（AZO）的铝诱导织构（AIT）玻璃，以替代常用的带有织构蚀刻AZO超基板的平面玻璃。研究了四种具有不同表面粗糙度和不同横向特征尺寸的AIT玻璃对非晶硅氢化太阳能电池光捕获的影响。为作比较，还研究了两种参考超基板：覆盖有未蚀刻AZO的平面玻璃和覆盖有织构蚀刻AZO的平面玻璃。将单结非晶硅氢化太阳能电池沉积在每个超基板上，并测量和比较其散射特性（雾度和角分辨散射）以及太阳能电池特性（电流-电压和外部量子效率）。结果表明，带有未蚀刻AZO的AIT玻璃超基板提供了与标准参考超基板相似甚至更优的光捕获效果，这通过更高的短路电流Jsc和更高的外部量子效率得到证明。使用捕获光分数δ（基于AZO/非晶硅氢化硅界面处的积分光散射的一个量），我们表明在样品的散射区域中，Jsc随δ线性增加，而与所使用的超基板类型无关。
