Abstract:
Zero-dimensional environmentally friendly carbon quantum dots (CQDs) combined with two-dimensional materials have a wide range of applications in optoelectronic devices. We combined steady-state and transient absorption spectroscopies to study the energy transfer dynamics between CQDs and molybdenum disulfide (MoS
2). Transient absorption plots showed photoinduced absorption and stimulated emission features, which involved the intrinsic and defect states of CQDs. Adding MoS
2 to CQDs solution, the lowest unoccupied molecular orbital of CQDs transferred energy to MoS
2, which quenched the intrinsic emission at 390 nm. With addition of MoS
2, CQD-MoS
2 composites quenched defect emission at 490 nm and upward absorption, which originated from another energy transfer from the defect state. Two energy transfer paths between CQDs and MoS
2 were efficiently manipulated by changing the concentration of MoS
2, which laid a foundation for improving device performance.