Open AccessGraphitic carbon nitride quantum dots (g-C3N4) to improve photovoltaic performance of polymer solar cell by combining Förster resonance energy transfer (FRET) and morphological effects
Author(s) -
Saurabh Pareek,
Sobia Waheed,
Aniket Rana,
Punit Sharma,
Supravat Karak
Publication year - 2020
Publication title -
nano express
Language(s) - English
Resource type - Journals
ISSN - 2632-959X
DOI - 10.1088/2632-959x/ab9b2f
Subject(s) - materials science , quantum dot , solar cell , förster resonance energy transfer , nanotechnology , organic solar cell , carbon nitride , optoelectronics , photovoltaic system , polymer solar cell , polymer , fluorescence , chemistry , photocatalysis , optics , ecology , biochemistry , catalysis , physics , composite material , biology
In this study, multifunctionality of graphitic carbon nitride quantum dots (g-C 3 N 4 QDs) have been explored as a photovoltaic booster for polymer solar cell. Facile synthesis method of g-C 3 N 4 QDs using organic solvent like o-dichlorobenzene which is commonly used for cell fabrication, has been demonstrated. Photovoltaic effect formation and various effects of QDs on energy transfer, carrier transport and nanoscale film morphology of the devices have been investigated thoroughly by incorporating g-C 3 N 4 QDs as a third component into a well-established material combination of P3HT: PC 71 BM blend films. While systematic variation of device performances was observed with varying concentration of QDs, at an optimal concentration of 2%, almost 40% performance improvement was achieved compared to the pristine devices. The g-C 3 N 4 QDs were found to assist Förster resonance energy transfer (FRET) between the QDs and host polymer, improving overall energy harvesting capability of the devices. The emission spectra of g-C 3 N 4 QDs ( λ Ems = 400–550) and absorption spectra of P3HT ( λ Abs = 400–600) were found to have overlapping features which enabled the QDs to transfer ultraviolet region photon energy to P3HT. The g-C 3 N 4 QDs were also found to be favorable for maintaining nanoscale phase segregation of the active layer with improved crystallinity which is crucial for efficient exciton dissociation and faster charge extraction. The enhanced power conversion efficiency thus attributed to the combined consequences of improved morphology and FRET effect. This study opens new prospects for developing high-efficiency solution processable photovoltaic devices using g-C 3 N 4 QDs as the third component of the active layer.