Publications by authors named "Aradhana Panigrahi"

A comprehensive study on the photo-excited relaxation dynamics in semiconducting perovskite quantum dots (PQDs) is pivotal in realizing their extensive potential for optoelectronics applications. Among different competing photoinduced relaxation kinetics, energy transfer and charge transfer (CT) in PQDs need special attention, as they often influence the device efficacy, particularly with the donor-acceptor hybrid architecture. In this work, we explore a detailed investigation into photoinduced CT dynamics in mixed halide undoped CsPb(Br/Cl)3 and Mn2+ doped CsPb(Br/Cl)3 PQDs with a quinone molecule, p-benzoquinone (BQ).

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The lead halide perovskites have emerged as promising materials with intriguing photo-physical properties and have immense potential for photovoltaic applications. A comprehensive study on the kinetics of charge carrier (electron/hole) generation and transfer across the interface is key to realizing their future scope for efficient device engineering. Herein, we investigate the interfacial charge transfer (CT) dynamics in cesium lead halide (CsPbBr3) perovskite quantum dots (PQDs) with energetically favorable electron acceptors, anthraquinone (AQ) and p-benzoquinone (BQ), and hole acceptors such as pyrene and 4-(dimethylamino)pyridine (DMAP).

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Optimization of perovskite-based optoelectronic performance demands prudent engineering in the device architecture with facile transport of generated charge carriers. Herein, we explore the charge transfer (CT) kinetics in perovskite nanocrystals (PNCs), CsPbBr, with two redox-active quinones, menadione (MD) and anthraquinone (AQ), and its alteration in halide exchanged CsPbCl. With a series of spectroscopic and microscopic measurements, we infer that both electron and hole transfer (ET-HT) prevail in CsPbCl with quinones, resulting in a faster CT, while ET predominates for CsPbBr.

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Perovskites (PVKs) have emerged as an exciting class of semiconducting materials owing to their magnificent photophysical properties and been used in solar cells, light-emitting diodes, photodetectors, etc. The growth of multidimensional nanostructures has revealed many exciting alterations in their optoelectronic properties compared to those of their bulk counterparts. In this work, we have spotlighted the influence of quantum confinement in CsPbBr PVKs like the quantum dot (PQD), nanoplatelet (PNPL), and nanorod (PNR) on their charge transfer (CT) dynamics with 1,4-naphthoquinone (NPQ).

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Regulated excited state energy and charge transfer play a pivotal role in nanoscale semiconductor device performance for efficient energy harvesting and optoelectronic applications. Herein, we report the influence of Förster resonance energy transfer (FRET) on the excited-state dynamics and charge transport properties of metal halide perovskite nanocrystals (PNCs), CsPbBr, and its anion-exchanged counterpart CsPbCl with CdSe/ZnS quantum dots (QDs). We report a drop in the FRET efficiency from ∼85% (CsPbBr) to ∼5% (CsPbCl) with QDs, inviting significant alteration in their charge transport properties.

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Due to their uniqueness in tunable photophysics, transition metal dichalcogenide (TMD) based quantum dots (QDs) have emerged as the next-generation quantum materials for technology-based semiconductor applications. This demands frontline research on the rational synthesis of the TMD QDs with controlled shape, size, nature of charge migration at the interface, and their easy integration in optoelectronic devices. In this article, with a controlled solution-processed synthesis of MoS and WS QDs, we demonstrate the disparity in their structural, optical, and electrical characteristics in bulk and confinement.

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