Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences , Ningbo 315201, China.
Department of Materials Science and Engineering, Stanford University , Stanford, California 94305, United States.
ACS Nano. 2016 Dec 27;10(12):11525-11531. doi: 10.1021/acsnano.6b07511. Epub 2016 Dec 9.
Silicon/organic heterojunction solar cells (HSCs) based on conjugated polymers, poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), and n-type silicon (n-Si) have attracted wide attention due to their potential advantages of high efficiency and low cost. However, the state-of-the-art efficiencies are still far from satisfactory due to the inferior junction quality. Here, facile treatments were applied by pretreating the n-Si wafer in tetramethylammonium hydroxide (TMAH) solution and using a capping copper iodide (CuI) layer on the PEDOT:PSS layer to achieve a high-quality Schottky junction. Detailed photoelectric characteristics indicated that the surface recombination was greatly suppressed after TMAH pretreatment, which increased the thickness of the interfacial oxide layer. Furthermore, the CuI capping layer induced a strong inversion layer near the n-Si surface, resulting in an excellent field effect passivation. With the collaborative improvements in the interface chemical and electrical passivation, a competitive open-circuit voltage of 0.656 V and a high fill factor of 78.1% were achieved, leading to a stable efficiency of over 14.3% for the planar n-Si/PEDOT:PSS HSCs. Our findings suggest promising strategies to further exploit the full voltage as well as efficiency potentials for Si/organic solar cells.
基于共轭聚合物、聚(3,4-乙二氧基噻吩):聚(苯乙烯磺酸盐) (PEDOT:PSS) 和 n 型硅 (n-Si) 的硅/有机杂结太阳能电池 (HSCs) 由于其高效率和低成本的潜在优势而受到广泛关注。然而，由于较差的结质量，目前的效率仍然远远不能令人满意。在这里，通过在四甲基氢氧化铵 (TMAH) 溶液中预处理 n-Si 晶片，并在 PEDOT:PSS 层上使用铜碘 (CuI) 覆盖层，应用了简便的处理方法，以实现高质量的肖特基结。详细的光电特性表明，TMAH 预处理后表面复合大大抑制，增加了界面氧化层的厚度。此外，CuI 覆盖层在 n-Si 表面附近诱导出强反型层，从而实现了优异的场效应钝化。通过界面化学和电学钝化的协同改进，实现了具有竞争力的开路电压 0.656 V 和高填充因子 78.1%，从而使平面 n-Si/PEDOT:PSS HSCs 的稳定效率超过 14.3%。我们的研究结果表明，对于硅/有机太阳能电池，进一步开发全电压和效率潜力具有很有前景的策略。
