Optical properties of MnTe2 few-layer quantum dots

Quantum dots (QDs) are gaining attention as a possible emissive material that might be used in flexible optoelectronic and photonic systems. In the present work, the temperature-dependent photoluminescence (TDPL) property of manganese di-telluride (MnTe2) QDs was investigated. The room-temperature PL is attributed to the abrupt breakage of the large-area MnTe2 nanosheets by ultrasonication, which integrates defect-mediated localized trap states inside the electronic bandgap. As a result, deliberately generated defect states ultimately generate such PL emission of QDs. Density functional theory (DFT) results further validate the experimental interpretations of the origin of TDPL. In addition, through an in-situ liquid diffusion approach, the QDs were also integrated into a NaCl matrix. Due to light scattering properties, the hybrid crystals exhibit fluorescence centres at various excitation wavelengths. These results suggest that these MnTe2 QDs can be used as an effective basis for future flexible optoelectronic applications. [Display omitted] •Synthesis of MnTe₂ QDs via liquid phase exfoliation technique.•Synthesized QDs exhibit both excitonic and defect-related emissions.•DFT results support experimental interpretations of temperature-dependent PL.•QDs decorated NaCl hybrid crystal exhibits multiple scattering by QDs.•The scattering results in distinct emission at different excitation wavelengths.