Rudzikas Matas, Pakalka Saulius, Donėlienė Jolanta, Šetkus Arūnas
Center for Physical Sciences and Technology, Saulėtekio Av. 3, LT-10257 Vilnius, Lithuania.
The Applied Research Institute for Prospective Technologies, Vismaliukų Str. 34, LT-10243 Vilnius, Lithuania.
Materials (Basel). 2023 Sep 7;16(18):6107. doi: 10.3390/ma16186107.
Recently, the development of tandem devices has become one of the main strategies for further improving the efficiency of photovoltaic modules. In this regard, combining well-established Si technology with thin film technology is one of the most promising approaches. However, this imposes several limitations on such thin film technology, such as low prices, the absence of scarce or toxic elements, the possibility to tune optical properties and long lifetime stability. Therefore, to show the potential of kesterite/silicon tandems, in this work, a 2 terminal (2T) structure using pure germanium kesterite was simulated with combined SCAPS and transfer matrix methods. To explore the impact of individual modifications, a stepwise approach was adopted to improve the kesterite. For the bottom sub cell, a state-of-the-art silicon PERC cell was used with an efficiency of 24%. As a final result, 19.56% efficiency was obtained for the standalone top kesterite solar cell and 28.6% for the tandem device, exceeding standalone silicon efficiency by 4.6% and justifying a new method for improvement. The improvement observed could be attributed primarily to the enhanced effective lifetime, optimized base doping, and mitigated recombination at both the back and top layers of the CZGSSe absorber. Finally, colorimetric analysis showed that color purity for such tandem structure was low, and hues were limited to the predominant colors, which were reddish, yellowish, and purple in an anti-reflective coating (ARC) thickness range of 20-300 nm. The sensitivity of color variation for the whole ARC thickness range to electrical parameters was minimal: efficiency was obtained ranging from 28.05% to 28.63%.
最近，串联器件的发展已成为进一步提高光伏组件效率的主要策略之一。在这方面，将成熟的硅技术与薄膜技术相结合是最有前途的方法之一。然而，这对这种薄膜技术施加了一些限制，例如价格低廉、不存在稀缺或有毒元素、能够调整光学特性以及具有长寿命稳定性。因此，为了展示锡基硫属化合物/硅串联结构的潜力，在这项工作中，使用纯锗锡基硫属化合物的两终端（2T）结构通过SCAPS和转移矩阵方法进行了模拟。为了探索单个修改的影响，采用逐步方法来改进锡基硫属化合物。对于底部子电池，使用了效率为24%的先进硅PERC电池。最终结果是，独立的顶部锡基硫属化合物太阳能电池的效率为19.56%，串联器件的效率为28.6%，比独立的硅效率高出4.6%，证明了一种新的改进方法的合理性。观察到的改进主要可归因于有效寿命的提高、基区掺杂的优化以及CZGSSe吸收体的背层和顶层复合的减轻。最后，比色分析表明，这种串联结构的颜色纯度较低，色调仅限于主要颜色，在20 - 300nm的抗反射涂层（ARC）厚度范围内为微红、微黄和紫色。在整个ARC厚度范围内，颜色变化对电学参数的敏感性最小：获得的效率范围为28.05%至28.63%。
