Wuhan National Laboratory for Optoelectronics, and School of Optical and Electronic Information, Huazhong University of Science and Technology , Wuhan 430074, China.
Research Institute of Huazhong University of Science and Technology in Shenzhen , Shenzhen 518057, China.
ACS Appl Mater Interfaces. 2016 Dec 14;8(49):33899-33906. doi: 10.1021/acsami.6b13324. Epub 2016 Dec 1.
Inverted planar perovskite solar cells using poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) as the hole-transporting layer (HTL) are very attractive because of their low-temperature and easy processing. However, the planar cells with the PEDOT:PSS HTL typically display lower open-circuit voltage (V) (about 0.90 V) than that of devices with TiO-based conventional structure (1.0-1.1 V). The underlying reasons are still not clear. In this work, we report the PEDOT:PSS that is intrinsically p-doped can be chemically reduced by methylamine iodide (MAI) and MAPbI. The reaction reduces the work function (WF) of PEDOT:PSS, which suppresses the efficient hole collection and yields lower V. To overcome this issue, we adopt undoped semiconducting polymers that are intrinsically nonreduction-active (NRA) as the HTL for inverted planar perovskite solar cells. The cells display enhanced V from 0.88 ± 0.04 V (PEDOT:PSS HTL, reference cells) to 1.02 ± 0.03 V (P3HT HTL) and 1.04 ± 0.03 V (PTB7 and PTB-Th HTL). The power conversion efficiency (PCE) of the devices with these NRA HTL reaches about 17%.
用聚(3,4-亚乙基二氧噻吩):聚(苯乙烯磺酸盐) (PEDOT:PSS) 作为空穴传输层 (HTL) 的倒置平面钙钛矿太阳能电池因其低温和易于处理而非常有吸引力。然而，具有 PEDOT:PSS HTL 的平面电池的开路电压 (V) (约 0.90 V) 通常低于具有 TiO 基传统结构的器件 (1.0-1.1 V)。其根本原因尚不清楚。在这项工作中，我们报告了本征 p 型掺杂的 PEDOT:PSS 可以被碘化甲脒 (MAI) 和 MAPbI 化学还原。该反应降低了 PEDOT:PSS 的功函数 (WF)，抑制了有效的空穴收集，并导致了较低的 V。为了克服这个问题，我们采用了本征非还原活性 (NRA) 的无掺杂半导体聚合物作为倒置平面钙钛矿太阳能电池的 HTL。电池的 V 从 0.88 ± 0.04 V (PEDOT:PSS HTL，参考电池) 提高到 1.02 ± 0.03 V (P3HT HTL) 和 1.04 ± 0.03 V (PTB7 和 PTB-Th HTL)。这些具有 NRA HTL 的器件的功率转换效率 (PCE) 达到约 17%。
