A Highly Conductive Titanium Oxynitride Electron‐Selective Contact for Efficient Photovoltaic Devices
Xinbo Yang, Yuanbao Lin, Jiang Liu, Wenzhu Liu, Qunyu Bi, Xin Song, Jingxuan Kang, Fuzong Xu, Lujia Xu, Mohamed Nejib Hedhili, Derya Baran, Xiaohong Zhang, Thomas D. Anthopoulos, Stefaan De Wolf
Abstract
Abstract High‐quality carrier‐selective contacts with suitable electronic properties are a prerequisite for photovoltaic devices with high power conversion efficiency (PCE). In this work, an efficient electron‐selective contact, titanium oxynitride (TiO x N y ), is developed for crystalline silicon (c‐Si) and organic photovoltaic devices. Atomic‐layer‐deposited TiO x N y is demonstrated to be highly conductive with a proper work function (4.3 eV) and a wide bandgap (3.4 eV). Thin TiO x N y films simultaneously provide a moderate surface passivation and enable a low contact resistivity on c‐Si surfaces. By implementation of an optimal TiO x N y ‐based contact, a state‐of‐the‐art PCE of 22.3% is achieved for a c‐Si solar cell featuring a full‐area dopant‐free electron‐selective contact. Simultaneously, conductive TiO x N y is proven to be an efficient electron‐transport layer for organic photovoltaic (OPV) devices. A remarkably high PCE of 17.02% is achieved for an OPV device with an electron‐transport TiO x N y layer, which is superior to conventional ZnO‐based devices with a PCE of 16.10%. Atomic‐layer‐deposited TiO x N y ETL on a large area with a high uniformity may help accelerate the commercialization of emerging solar technologies.