Mei Xianglin, Wu Bin, Guo Xiuzhen, Liu Xiaolin, Rong Zhitao, Liu Songwei, Chen Yanru, Qin Donghuan, Xu Wei, Hou Lintao, Chen Bingchang
School of Materials Science and Engineering, South China University of Technology, Guangzhou 510640, China.
Institute of Polymer Optoelectronic Materials & Devices, State Key Laboratory of Luminescent Materials & Devices, South China University of Technology, Guangzhou 510640, China.
Nanomaterials (Basel). 2018 Aug 13;8(8):614. doi: 10.3390/nano8080614.
Nanocrystal solar cells (NCs) allow for large scale solution processing under ambient conditions, permitting a promising approach for low-cost photovoltaic products. Although an up to 10% power conversion efficiency (PCE) has been realized with the development of device fabrication technologies, the open circuit voltage () of CdTe NC solar cells has stagnated below 0.7 V, which is significantly lower than most CdTe thin film solar cells fabricated by vacuum technology (around 0.8 V0.9 V). To further improve the NC solar cells' performance, an enhancement in the towards 0.8⁻1.0 V is urgently required. Given the unique processing technologies and physical properties in CdTe NC, the design of an optimized band alignment and improved junction quality are important issues to obtain efficient solar cells coupled with high . In this work, an efficient method was developed to improve the performance and of solution-processed CdTe nanocrystal/TiO₂ hetero-junction solar cells. A thin layer of solution-processed CdS NC film (5 nm) as introduced into CdTe NC/TiO₂ to construct hetero-junction solar cells with an optimized band alignment and - junction quality, which resulted in a low dark current density and reduced carrier recombination. As a result, devices with improved performance (5.16% compared to 2.63% for the control device) and a as high as 0.83 V were obtained; this value is a record for a solution-processed CdTe NC solar cell.
纳米晶体太阳能电池（NCs）能够在环境条件下进行大规模溶液处理，为低成本光伏产品提供了一种很有前景的方法。尽管随着器件制造技术的发展，功率转换效率（PCE）已达到10%，但CdTe NC太阳能电池的开路电压（）一直停滞在0.7 V以下，这明显低于大多数通过真空技术制造的CdTe薄膜太阳能电池（约0.8 V~0.9 V）。为了进一步提高NC太阳能电池的性能，迫切需要将提高到0.8⁻1.0 V。鉴于CdTe NC独特的处理技术和物理性质，设计优化的能带排列和改善结质量是获得高效太阳能电池并提高的重要问题。在这项工作中，开发了一种有效的方法来提高溶液处理的CdTe纳米晶体/TiO₂异质结太阳能电池的性能和。将一层溶液处理的CdS NC薄膜（约5 nm）引入CdTe NC/TiO₂中，以构建具有优化能带排列和结质量的异质结太阳能电池，这导致了低暗电流密度并减少了载流子复合。结果，获得了性能得到改善的器件（5.16%，而对照器件为2.63%）以及高达0.83 V的；该值是溶液处理的CdTe NC太阳能电池的记录。
