Carbon-based perovskite solar cells (C-PSCs) have been extensively researched as alternatives to fabricate cost-effective energy conversion devices. The interface of the perovskite film and the carbon electrode is crucial for achieving good photovoltaic performance. Herein, two carbon quantum dots (CQDs) with different functional groups designated as A-CQDs and CA-CQDs are used to passivate the perovskite CH3NH3PbI3 surface, respectively. The surface ligand effect arising from the two CQDs is extensively investigated. The introduction of the A-CQDs passivation layer not only forms large crystal grains and decreases the defect density of the perovskite film but also well adjusts the energy level matching of the perovskite film and the carbon electrode, thereby promoting efficient carrier transfer. The C-PSC passivated by the A-CQDs film shows an improved photovoltaic property with a champion power conversion efficiency (PCE) of 13.97%. PCEs of the control PSCs and PSCs based on the CA-CQDs layer are 11.29% and 10.77%, respectively. Furthermore, A-CQDs-based C-PSCs retain more than 80% of their initial PCE under testing conditions of 35% humidity for 840 h of storage.

A novel polymer electrolyte poly(NAG) prepared from commercially available transparent photocurable nail art glue NAG is successfully developed for quasi-solid state dye sensitized solar cells (QS-DSSCs) application. The functional component in this poly(NAG) is revealed to be acrylate based group from the Fourier transform infrared spectroscopy (FTIR) measurement. Water contact angles tests showthe poly(NAG) films displayed contact angle less than 20° when dripping liquid electrolyte containing iodide/tri-iodide redox couple. Meanwhile, electrochemical properties of poly(NAG) polymer based electrolyte are thoroughly investigated by cyclic voltammetry (CV) and electrochemical impedance-1 spectroscopy (EIS). The poly(NAG) polymer electrolyte presents an a highest ionic conductivity of 0.51 mS•cm at room-temperature. Solar cell based on the poly(NAG) electrolyte reaches power conversion efficiency (PCE) of 1.46%. This work demonstrates that this NAG is a novel, cheap, environmental friendly and efficient precursor for preparing polymer electrolyte for DSSCs application. Its abundance can significantly reduce cell fabrication cost, and this work opens a new way to look for promising resource for the application of DSSCs.