基于WOx/PEDOT:PSS复合空穴传输层的高效稳定平面异质结钙钛矿太阳电池

在基于钙钛矿/富勒烯平面异质结的钙钛矿太阳电池中，PEDOT:PSS是最常使用的空穴传输材料. 但PEDOT:PSS呈酸性，会腐蚀金属氧化物透明电极，使器件的电极界面稳定性欠佳. 本文将高功函的氧化钨（WO_x）插入到PEDOT:PSS和FTO之间，形成WO_x/PEDOT:PSS复合空穴传输层，这样既可以避免PEDOT:PSS与FTO直接接触，提高器件的稳定性，又可以进一步降低电极界面的接触势垒，从而提升器件的性能. 作者研究了复合传输层对透光率、钙钛矿形貌、钙钛矿结晶、光伏性能及器件稳定性的影响. 基于WO_x/PEDOT:PSS复合空穴传输层的电池效率可以达到12.96%，比单纯的PEDOT:PSS的电池效率(10.56%)提升了22.7%，同时器件的稳定性也得到大幅改善.

WOx/PEDOT:PSS double-layered Hole-transport Layers for Efficient and Stable Planar Heterojunction Perovskite Solar Cells

Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is a commonly used hole-transport material in the perovskite solar cells (PerSCs) structure of perovskite/fullerene planer heterojunction, but it also has a negative effect on the stability of device because of its acidity which will corrode metal oxide transparent electrodes. In this work, aWO_x hole-transport layer with high work function was inserted into the PEDOT: PSS and FTO to enhance the stability and photovoltaic performance. The insertedWO_x layer not only can avoid direct contact between PEDOT:PSS and FTO, but also can further reduce the contact barrier between the electrode interface. We studied the effect ofWO_x/PEDOT:PSS double-layered hole transport layers on the optical transmittance, the morphology and crystals of perovskite, the photovoltaic performance and the stability of the devices. The power conversion efficiency (PCE) of PerSCs can be improved from 10.56% (with PEDOT:PSS layer) to 12.96% withWO_x/PEDOT:PSS double-layered hole transport layers, and the stability of the device has also been greatly improved.