Publications by authors named "Asit Baran Mahato"

Single-particle photoluminescence measurements have been extensively utilized to investigate the charge carrier dynamics in quantum dots (QDs). Among these techniques, single dot blinking studies are effective for probing relatively slower processes with timescales >10 ms, whereas fluorescence correlation spectroscopy (FCS) studies are suited for recording faster processes with timescales typically <1 ms. In this study, we utilized scanning FCS (sFCS) to bridge the ms gap, thereby enabling the tracking of carrier dynamics across an extended temporal window ranging from μs to subsecond.

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Article Synopsis
  • The study investigates how carriers behave in CdSe/ZnS quantum dots using fluorescence-lifetime-correlation-spectroscopy (FLCS) and single-dot photoluminescence (PL) blinking.
  • It distinguishes between the emission of photons from exciton and trap states by analyzing their lifetimes and establishes correlation functions that reveal similar diffusion times across both states.
  • The findings suggest that different states contribute to the blinking phenomenon, with shallow trap states dominating at lower excitation powers and trion recombination influencing behavior at higher powers, showcasing the potential for a comprehensive understanding of charge dynamics in these quantum dots.
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Photoluminescence (PL) blinking of nanoparticles, while detrimental to their imaging applications, may benefit next-generation displays if the blinking is precisely controlled by reversible electron/hole injections from an external source. Considerable efforts are made to create well-characterized charged excitons within nanoparticles through electrochemical charging, which has led to enhanced control over PL-blinking in numerous instances. Manipulating the photocharging/discharging rates in nanoparticles by surface engineering can represent a straightforward method for regulating their blinking behaviors, an area largely unexplored for perovskite nanocrystals (PNCs).

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This Letter reports the facile harvesting of hot carriers (HCs) in a composite of 12-faceted dodecahedron CsPbBr nanocrystal (NC) and a scavenger molecule. We recorded ∼3.3 × 10 s HC cooling rate in NC when excited with ∼1.

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