Application of Fluorescent CQDs for Enhancing the Performance of Solar Cells and WLEDs

Abstract

Carbon quantum dots (CQDs) are emerging as promising materials for applications like flexible or transparent solar cell, white light emitting diodes (WLEDs), etc. due to their low cost, eco-friendliness, substantial absorption coefficient, wide absorption spectrum, tuneable optical properties, good charge transfer/separation ability, good quantum yield and large two-photon absorption cross-section. They have been employed in solar cells as active absorbing layers, electron acceptors/donors, electron sinks, electron transporting layers (ETL), hole transporting layers (HTLs), dopants, and interlayer spacing. Consequently, such solar cells have exhibited enhanced performance. In contrast to commercial rare-earth phosphors and traditional semiconductor quantum dots (SQDs) (usually toxic), CQDs exhibit wide range of emission characteristics [full width half maxima (FWHM) > 80 nm]. Interestingly, the emission characteristics of these nanomaterials are tuneable which makes them suitable for WLEDs applications. Red-CQDs are gaining importance as they are required to realize the warm WLEDs. Though a lot of work has been done to modulate the properties of CQDs in order to enhance the performance of solar cells and WLEDs, there are immense possibilities to further exploit the potential of CQDs in these applications.