Solution-Processed in Situ Growth of CuInS2 Nanoparticle Films for Efficient Planar Heterojunction Solar Cells with a Dual Nature of Charge Generation
Solution-Processed in Situ Growth of CuInS2 Nanoparticle Films for Efficient Planar Heterojunction Solar Cells with a Dual Nature of Charge Generation
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用于具有电荷生成双重性质的高效平面异质结太阳能电池的 CuInS2 纳米颗粒薄膜的溶液处理原位生长
DOI：
10.1021/acsaem.9b00915
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发表时间：
2019-07-01
影响因子：
6.4
通讯作者：
Wang, Mingtai
中科院分区：
文献类型：
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作者：
Chen, Wangwei;Qi, Juanjuan;Wang, Mingtai
报道了一种简便的溶液处理方法，该方法利用稳定的分子前驱体溶液，并重复旋涂和退火以实现薄膜生长，用于在TiO₂/CdS薄膜上原位生长CuInS₂纳米颗粒薄膜，从而为高效太阳能电池提供TiO₂/CdS/CuInS₂三元上层异质结薄膜。使用Spiro - OMeTAD作为空穴传输材料（HTM）制造了新型稳定的平面太阳能电池，在CuInS₂厚度优化为200 nm且CuInS₂形成的退火温度为270℃时，在AM 1.5光照下实现了6.31%的峰值功率转换效率。该效率在由分子前驱体方法制备的基于CuInS₂的平面太阳能电池中是最高的；特别是，采用HTM使得开路电压高达0.78 V，远高于没有HTM的类似器件。我们的结果表明在此类太阳能电池中存在激子和非激子电荷产生机制的双重特性。提出了一种耗尽场辅助的同质结 - 界面电荷转移模型来解释CuInS₂纳米颗粒薄膜中自由电荷载流子的产生和转移，并且结合激子特性，该模型很好地阐明了TiO₂/CdS/CuInS₂太阳能电池中的总电荷产生。此外，发现CdS层可作为一种有效的界面间隔物，防止CuInS₂吸收时产生的电荷载流子复合。
A facile solution-processing method featuring the applications of a stable molecular precursor solution and the repetition of spin-coating and annealing for film growth is reported for the in situ growth of CuInS2 nanoparticle films on TiO2/CdS film to provide TiO2/CdS/CuInS2 ternary superstrate heterojunction films for efficient solar cells. The novel and stable planar solar cells are fabricated using Spiro-OMeTAD as hole transporting material (HTM) and achieved a peak power conversion efficiency of 6.31% under AM 1.5 illumination at the optimized CuInS2 thickness of 200 nm and annealing temperature of 270 °C for CuInS2 formation. The efficiency is the highest among the CuInS2-based planar solar cells derived from molecular precursor methods; in particular, adopting HTM results in the open-circuit voltage up to 0.78 V, much higher than that of the similar devices without HTM. Our results demonstrate a dual nature of excitonic and nonexcitonic charge generation mechanisms in such solar cells. A depletion-...