Transient Absorption Analysis on Energy Transfer from Carbon Quantum Dots to Tungsten Disulfide

The combination of carbon quantum dots (CQDs) with transition metal disulfides results in 0D–2D composites with enhanced light absorption properties. In the transient absorption spectrum of CQD–WS2 composites, photoinduced absorption feature of the intrinsic state was inhibited by WS2. The suppressed photoinduced absorption feature of the defect state appeared at a particular WS2 concentration (0.1–0.13 mg/mL), which indicates that the capture ability of the defect state is enhanced by WS2. Transient absorption spectrum reveals the energy transfer dynamics from intrinsic and defect states of CQDs to WS2. Energy transfer efficiency can reach up to 92% at 0.2 mg/mL WS2. The understanding and manipulation of energy transfer dynamics in 0D–2D composites has made great contributions in optical devices.