Strong quantum-confined excitation and emission from violet phosphorus quantum dots

Abstract

As a new type of two-dimensional semiconductor material, violet phosphorus (VP) has recently attracted much attention for applications in the field of optoelectronics. Although mechanical exfoliation has been used to prepare VP nanoribbons or nanosheets, production of the high quantum yield VP quantum dots (VPQDs) remains a challenge. Herein, the VPQDs are prepared via liquid exfoliation in ethanol and subsequent solvothermal treatment under 180 °C in dimethylformamide. The prepared VPQDs have a mean size of about 2 nm and can emit a strong blue photoluminescence (PL) when exchanged in ethanol solution. The quantum yield can reach 8.6%. The strong PL arises from both the band-to-band recombination related to quantum confinement effects and P-O-C related surface bonding state. Furthermore, the VPQDs solution has a good photostability under ambient conditions, suggesting their possible potential in fluorescent biological imaging and photocatalytic reactions.