Tin sulfide SnS, SnS2 thin films have been fabricated and investigated for solar cell application as prospective inexpensive and environmentally safe material. Today, SnSx-based single bandgap and tandem solar cell designs demonstrate promising results as environment-friendly and cheap alternative to common Si, CdTe, CIGS cells. To enhance further the solar spectrum utilization, the graded bandgap structures are preffered. The chemical deposition of tin sulfide films presents a low-cost and scalable processing for thin-film solar cells mass production. In the paper, the successive ionic layer adsorption and reaction (SILAR) technique was used to produce SnSx layers, including successive cyclic dipping into Na2S and SnCl2 + NaCl + triethanolamine solutions. The XRD measurements reveal the SnS, SnS2 layers formation with nanograins micromorphology. The optical transmission measurements show the variable bandgap values depending, presumably, on the nanograins size. In this study, we propose and analyse, using SCAPS code simulation, a simple graded bandgap heterostructure solar cell structure based on nanostructured bandgap-engineered SnS/SnS2 active layers showing conversion efficiency up to ~ 14% for non-graded and ~ 16% for graded bandgap heterostructure.

中文翻译：

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分级带隙纳米结构的基于 SnS 的光电池

硫化锡 SnS、SnS2 薄膜已被制造和研究用于太阳能电池应用，作为预期的廉价和环境安全材料。今天，基于 SnSx 的单带隙和串联太阳能电池设计作为普通 Si、CdTe、CIGS 电池的环保且廉价的替代品展示了有希望的结果。为了进一步提高太阳光谱的利用率，优选分级带隙结构。硫化锡薄膜的化学沉积为薄膜太阳能电池的大规模生产提供了一种低成本和可扩展的工艺。在本文中，连续离子层吸附和反应 (SILAR) 技术用于生产 SnSx 层，包括连续循环浸入 Na2S 和 SnCl2 + NaCl + 三乙醇胺溶液中。XRD 测量揭示了具有纳米晶粒微观形态的 SnS、SnS2 层的形成。光传输测量显示可变带隙值，大概取决于纳米晶粒尺寸。在本研究中，我们使用 SCAPS 代码模拟提出并分析了一种基于纳米结构带隙工程 SnS/SnS2 活性层的简单渐变带隙异质结构太阳能电池结构，其转换效率高达约 14% 的非渐变和约 16% 的分级带隙异质结构。