Light-emitting TiN (MXene) quantum dots: synthesis, characterization and theoretical calculations

• Published in: Journal of materials chemistry. C, Materials for optical and electronic devices Materials for optical and electronic devices, 2022-04, Vol.1 (16), p.658-6514
• Main Authors: Sharbirin, Anir S, Roy, Shrawan, Tran, Trang Thu, Akhtar, Sophia, Singh, Jaspal, Duong, Dinh Loc, Kim, Jeongyong
• Format: Article
• ISSN: 2050-7526; 2050-7534
• DOI: 10.1039/d2tc00568a

MXene-based quantum dots (MQDs), which are obtained by fragmenting MXenes into a nanometer scale, can display photoluminescence (PL), suggesting light-emitting applications for bandgap-less MXenes. However, despite the diverse possible formations of MXene components, only carbide MXene-based MQDs have been reported to emit light. In this study, we synthesized water-soluble MQDs with an average diameter of 3.14 nm using the titanium nitride (Ti 2 N) MXene. Ti 2 N MQDs exhibited efficient PL, with a maximum quantum yield of 7.5%, upon light absorption over the deep UV wavelength range of 400-230 nm. The density functional theory calculations and PL excitation measurements identified a bandgap of 3.8 eV and the existence of an unfulfilled band (E 1 ) between the occupied low-energy (E 0 ) and unoccupied high-energy (E 2 ) bands, which induces strong absorption in deep UV energy originating from the E 0 -E 2 transition. Light-emitting nitride MQDs expand and facilitate the UV optoelectronic applications of MQDs. Titanium nitride (Ti 2 N) MXene QDs display efficient deep-UV absorption and light emission.