Research Projects

Semiconductor quantum dots (QDs) are of immense interest in a wide range of applications including light-emitting diodes (LEDs), solar cells, photocatalysis, and quantum light sources owing to their strong light absorption and bright narrowband emission across the visible and infrared. A combination of the strong light absorption property of plasmonic metals with such QDs may have enormous potential for solar-energy conversion due to long-lived hot plasmonic electrons. Within the QDs, Coulomb-bound electron-hole pairs, or excitons, are of fundamental importance, as they directly influence the charge transport properties that govern the optoelectronic performances. Therefore, in plasmonic QDs, it is very important to understand the nature of exciton-plasmon interaction. While recently emerged lead-halide perovskites are appealing candidates for optoelectronic applications, only one clear exciton resonance is observed for 2D perovskite nanoplatelets while for 3D perovskite nanocubes, one broad exciton resonance is observed in the linear absorption spectra. The very recent development of 0 D spherical-like perovskite QDs depicts clear exciton resonances up to four excitons in their linear absorption spectra, rendering them an ideal candidate to investigate excision-plasmon interaction for the first few excitons, the key point of investigation of the present proposal. While exciton-plasmon coupling has been investigated in other semiconductors, there are only a few research publications available on plasmonic perovskites, having only one exciton, leaving the field very much in its infancy. Size-tunable 0 D spherical-like perovskite QDs will be synthesized using the recently developed room-temperature colloidal method. Plasmonic metals, such as Au, Ag, and Cu will be doped into these QDs using our recently developed ligand shuttling approach. The optical properties of plasmonic perovskite QDs will be investigated using steady-state absorption, photoluminescence (PL), and time-resolved PL measurements. Finally, the knowledge of the exciton-plasmon coupling which strongly governs the charge transport properties of QDs will be utilized for photocatalytic applications.