Elsmani Mohammed Islam, Fatima Noshin, Torres Ignacio, Fernández Susana, Jallorina Michael Paul A, Chelvanathan Puvaneswaran, Rais Ahmad Rujhan Mohd, Daud Mohd Norizam Md, Nasir Sharifah Nurain Syed, Sepeai Suhaila, Ludin Norasikin Ahmad, Teridi Mohd Asri Mat, Sopian Kamaruzzaman, Ibrahim Mohd Adib
Solar Energy Research Institute (SERI), Universiti Kebangsaan Malaysia, Bangi 43600, Selangor, Malaysia.
Departamento de Energías Renovables, CIEMAT, 28040 Madrid, Spain.
Materials (Basel). 2022 Jul 19;15(14):5024. doi: 10.3390/ma15145024.
The silicon heterojunction solar cell (SHJ) is considered the dominant state-of-the-art silicon solar cell technology due to its excellent passivation quality and high efficiency. However, SHJ's light management performance is limited by its narrow optical absorption in long-wave near-infrared (NIR) due to the front, and back tin-doped indium oxide (ITO) layer's free carrier absorption and reflection losses. Despite the light-trapping efficiency (LTE) schemes adopted by SHJ in terms of back surface texturing, the previous investigations highlighted the ITO layer as a reason for an essential long-wavelength light loss mechanism in SHJ solar cells. In this study, we propose the use of Molybdenum disulfide (MoS) as a way of improving back-reflection in SHJ. The text presents simulations of the optical response in the backside of the SHJ applying the Monte-Carlo raytracing method with a web-based Sunsolve high-precision raytracing tool. The solar cells' electrical parameters were also resolved using the standard electrical equivalent circuit model provided by Sunsolve. The proposed structure geometry slightly improved the SHJ cell optical current density by ~0.37% (rel.), and hence efficiency () by about 0.4% (rel.). The SHJ cell efficiency improved by 21.68% after applying thinner back ITO of about 30 nm overlayed on ~1 nm MoS. The efficiency improvement following the application of MoS is tentatively attributed to the increased NIR absorption in the silicon bulk due to the light constructive interface with the backside components, namely silver (Ag) and ITO. Study outcomes showed that improved SHJ efficiency could be further optimized by addressing front cell components, mainly front ITO and MoS contact engineering.
硅异质结太阳能电池（SHJ）因其优异的钝化质量和高效率而被认为是目前最先进的硅太阳能电池技术。然而，由于正面和背面掺锡氧化铟（ITO）层的自由载流子吸收和反射损失，SHJ的光管理性能受到其在长波近红外（NIR）波段狭窄光学吸收的限制。尽管SHJ在背面纹理化方面采用了光捕获效率（LTE）方案，但先前的研究强调ITO层是SHJ太阳能电池中重要的长波长光损失机制的一个原因。在本研究中，我们提出使用二硫化钼（MoS）来改善SHJ中的背反射。本文使用基于网络的Sunsolve高精度光线追踪工具，应用蒙特卡罗光线追踪方法对SHJ背面的光学响应进行了模拟。还使用Sunsolve提供的标准等效电路模型解析了太阳能电池的电学参数。所提出的结构几何形状使SHJ电池的光电流密度略有提高，约提高了0.37%（相对），因此效率（）提高了约0.4%（相对）。在约1nm的MoS上覆盖约30nm的更薄背面ITO后，SHJ电池效率提高了21.68%。应用MoS后效率的提高初步归因于与背面组件（即银（Ag）和ITO）的光建设性界面导致硅体中近红外吸收增加。研究结果表明，通过优化正面电池组件，主要是正面ITO和MoS接触工程，可以进一步优化SHJ的效率。
