Department of Chemical and Biomolecular Engineering Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-749, Republic of Korea.
Nanoscale. 2017 Aug 31;9(34):12677-12683. doi: 10.1039/c7nr03265j.
Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is a popular and promising hole transport material for making efficient inverted-planar perovskite solar cells (IP-PSCs). However, the mismatch between the work function of conventional PEDOT:PSS and the valence band maximum of perovskite materials is still a challenge for efficient hole extraction. Here, we report systematic studies on the work-function modification and thermodynamic morphological evolution of PEDOT:PSS films by tuning the PSS/PEDOT ratio, along with its effects on the photovoltaic responses of IP-PSCs. We found that the open-circuit voltage (V) of an IP-PSC could be enhanced by controlling the work function of PEDOT:PSS. Furthermore, the optical transmittance of the PEDOT:PSS film could be maximized by controlling the morphological evolution, which will further increase the short-circuit current density (J) of the IP-PSC. The V and J of the IP-PSC with the optimized PEDOT:PSS composition increased from 0.88 to 0.93 V and from 17.11 to 20.77 mA cm, respectively, compared with an IP-PSC containing commercial PEDOT:PSS, which results in a power conversion energy that is greatly improved from 12.39 to 15.24%.
聚（3,4-亚乙基二氧噻吩）：聚（苯乙烯磺酸盐）（PEDOT:PSS）是一种很受欢迎且有前途的空穴传输材料，可用于制备高效的倒置平面钙钛矿太阳能电池（IP-PSCs）。然而，传统 PEDOT:PSS 的功函数与钙钛矿材料的价带最大值之间的不匹配仍然是高效空穴提取的一个挑战。在这里，我们通过调节 PSS/PEDOT 比例，对 PEDOT:PSS 薄膜的功函数修饰和热力学形态演化进行了系统研究，及其对 IP-PSCs 光伏响应的影响。我们发现，通过控制 PEDOT:PSS 的功函数，可以提高 IP-PSC 的开路电压（V）。此外，通过控制形态演化，可以最大化 PEDOT:PSS 薄膜的光透过率，这将进一步提高 IP-PSC 的短路电流密度（J）。与含有商业 PEDOT:PSS 的 IP-PSC 相比，优化后的 PEDOT:PSS 组成的 IP-PSC 的 V 和 J 分别从 0.88 增加到 0.93 V 和从 17.11 增加到 20.77 mA cm，这导致其能量转换效率从 12.39 大幅提高到 15.24%。
