Fogging, reflection, and dust-free transparent conducting glasses based on superhydrophilic nanotextures for organic photovoltaics

We present the preparation of high-efficiency organic photovoltaics (OPVs) using functional transparent conducting oxide glasses (functional TCOs) based on superhydrophilic nanotextures under fogging conditions. The superhydrophilic nanotextures are easily prepared with spin-coating of aged colloidal silica suspensions on the non-conducting side of indium tin oxide glasses (ITOs). PEDOT:PSS is used as a hole transport layer (HTL) in OPVs with PTB7/PC₇₁BM as a bulk hetero-junction layer (BHJ layer). The OPVs based on functional TCOs were confirmed by atomic force microscopy (AFM), scanning electron microscopy (SEM), water contact angle, UV–vis spectroscopy, and external quantum efficiency (EQE) measurements. Compared with the conventional TCOs, the functional TCOs, which have superhydrophilicity, axial gradient in refractive index, substantially suppress fogging and reduce reflection, leading to significantly improved light harvesting. The efficiency of OPVs based on functional TCOs (4.4%) were higher than those of OPVs with conventional TCOs (2.9%) under fogging conditions. This work has also demonstrated on superhydrophilic nanotextures based functional TCOs with excellent dust-free and self-cleaning performance.