The optical properties and solar energy conversion applications of carbon quantum dots: A review. (15th January 2020)

• Record Type: Journal Article
• Authors: Molaei, Mohammad Jafar
• Is Part Of: Solar energy. Volume 196(2020)
• Page Start: 549
• Page End: 566
• Publication Date: 2020-01-15
• Subjects: Carbon quantum dots -- Fluorescence -- Photocatalysis -- Solar cell -- Photoelectrochemical cell; Solar energy -- Periodicals; Solar engines -- Periodicals; 621.47
• DOI: 10.1016/j.solener.2019.12.036
• Languages: English
• ISSNs: 0038-092X

Abstract

Highlights: CQDs can suppress electron-holes pairs recombination by acting as an electron sink. CQDs can suppress electron-holes pairs recombination in semiconductors/CQDs nanocomposite. Photo-generated electrons can be transported by the conductive network of the CQDs. CQDs can generate electron-hole pairs. Abstract: Carbon quantum dots (CQDs) are emerging nanostructures which consist of carbon atoms and are typically below 10 nm in size. The CQDs are almost surface passivated or are functionalized with organics or biomolecules. CQDs have superior properties such as fluorescence emission, water-solubility, cheap and easy synthesis methods, low toxicity, biocompatibility, easy functionalization, and chemical inertness. The CQDs have found versatile applications in different areas such as in vivo and in vitro bioimaging, drug delivery, gene delivery, sensors, solar energy conversion, photoelectrochemical (PEC) cells, photovoltaic solar cells, photocatalysis, and light-emitting diodes (LEDs). CQDs could impart in photocatalytic reactions from two aspects; CQDs can be used alongside semiconductors as electron sink and could suppress electron-hole recombination and also CQDs can generate electron-hole pairs, as well. The CQDs with a wide spectral absorption and high absorption coefficients can enhance the photocatalytic activity. CQDs can also be used as sensitizers in the photoanode of solar cells. Due to the low cost and low toxicity of the CQDs in comparison to semiconductor quantum dots (QDs), they could be considered as potential alternatives in solar energy conversion applications. In this review, the CQDs are introduced and their optical properties are clarified. Recent advances of the CQDs in photocatalysis, PEC, and solar cells are reviewed.