Role of carbon nanodots in defect passivation and photo-sensitization of mesoscopic-TiO2 for perovskite solar cells. (May 2019)

• Record Type: Journal Article
• Authors: Sidhik, Siraj; Velusamy, Jayaramakrishnan; De la Rosa, Elder; Pérez-García, Sergio Alfonso; Ramos-Ortiz, Gabriel; López-Luke, Tzarara
• Is Part Of: Carbon. Volume 146(2019)
• Page Start: 388
• Page End: 398
• Publication Date: 2019-05
• Subjects: Carbon -- Periodicals; Carbone -- Périodiques; Koolstof; Toepassingen; Electronic journals; 546.681
• DOI: 10.1016/j.carbon.2019.01.105
• Languages: English
• ISSNs: 0008-6223

Abstract

Abstract: In this work, a recently developed carbon nanodots (CnDs) were introduced in the mesoscopic TiO2 to form a TiO2 : CnDs composite, to be used as an electrode in CH3 NH3 PbI3 based perovskite devices. It resulted the improvement in morphology of perovskite film and induced a carbon-doping passivating the oxygen defects. In addition, the presence of carbon dots enhanced the charge carrier mobility of TiO2 and provided extra photo-generation ability to the perovskite device due to its absorbing nature. The improved morphology, carbon-doping, photogeneration ability and the improved charge transfer characteristics with the introduction of carbon dots was verified by the scanning electron microscopy (SEM), atomic force microscopy (AFM), X-Ray photoelectron spectroscopy (XPS), UV-visible absorption, X-ray diffraction, space charge limited current (SCLC) measurement, photoluminescence (PL), electrochemical impedance spectroscopy (EIS), current leakage and open circuit photovoltage decay (OCPD) measurements. An optimized concentration of CnDs (3 wt%) within the TiO2 resulted in a maximum power conversion efficiency of 19.45% with negligible hysteresis, which is 16% higher than the device with pristine TiO2 . Graphical abstract: Image 1