AI Article Synopsis

  • * The study introduces a model system with sulfur vacancies in CdSeS NCs, creating a donor state that leads to long-lived intragap luminescence and improved emission efficiency up to 85%.
  • * Magneto-optical measurements reveal that the localized electrons are unaffected by the NC bands, with the photohole spin dynamics slowed due to reduced exchange interactions.

Article Abstract

Controlled insertion of electronic states within the band gap of semiconductor nanocrystals (NCs) is a powerful tool for tuning their physical properties. One compelling example is II-VI NCs incorporating heterovalent coinage metals in which hole capture produces acceptor-bound excitons. To date, the opposite donor-bound exciton scheme has not been realized because of the unavailability of suitable donor dopants. Here, we produce a model system for donor-bound excitons in CdSeS NCs engineered with sulfur vacancies () that introduce a donor state below the conduction band (CB), resulting in long-lived intragap luminescence. -localized electrons are almost unaffected by trapping, and suppression of thermal quenching boosts the emission efficiency to 85%. Magneto-optical measurements indicate that the are not magnetically coupled to the NC bands and that the polarization properties are determined by the spin of the valence-band photohole, whose spin flip is massively slowed down due to suppressed exchange interaction with the donor-localized electron.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8397387PMC
http://dx.doi.org/10.1021/acs.nanolett.1c01818DOI Listing

Publication Analysis

Top Keywords

donor-bound excitons
8
optical magneto-optical
4
magneto-optical properties
4
properties donor-bound
4
excitons vacancy-engineered
4
vacancy-engineered colloidal
4
colloidal nanocrystals
4
nanocrystals controlled
4
controlled insertion
4
insertion electronic
4

Similar Publications

Enhanced interactions of excitonic complexes in free-standing WS.

Nanoscale

December 2023

School of Engineering, College of Engineering and Computer Science, the Australian National University, Canberra, ACT, 2601, Australia.

Excitonic complexes, bound states of electrons and holes, provide a promising platform in monolayer transition-metal dichalcogenide (TMDC) semiconductors for investigating diverse many-body interaction phenomena. The surrounding dielectric environment has been found to strongly influence the excitonic properties of the TMDC monolayers. While the impact of different dielectric surroundings on two-dimensional semiconductor materials and their strong correlations have been well studied, the effects on exciton formation and its properties resulting from a further reduction in dielectric screening remain elusive.

View Article and Find Full Text PDF

All-Oxide Transparent Photodetector Array for Ultrafast Response through Self-Powered Excitonic Photovoltage Operation.

Small

August 2023

Photoelectric and Energy Device Application Lab (PEDAL) and Multidisciplinary Core Institute for Future Energies (MCIFE), Incheon National University, Incheon, 22012, South Korea.

Can photodetectors be transparent and operate in self-powered mode? Is it possible to achieve invisible electronics, independent of the external power supply system, for on-site applications? Here, a ZnO/NiO heterojunction-based high-functional transparent ultraviolet (UV) photodetector operating in the self-powered photovoltaic mode with outstanding responsivity and detectivity values of 6.9 A W and 8.0 × 10 Jones, respectively, is reported.

View Article and Find Full Text PDF

Correlations between Cascaded Photons from Spatially Localized Biexcitons in ZnSe.

Nano Lett

December 2022

Institute for Research in Electronics and Applied Physics and Joint Quantum Institute, University of Maryland, College Park, Maryland 20742, United States.

Radiative cascades emit correlated photon pairs, providing a pathway for the generation of entangled photons. The realization of a radiative cascade with impurity atoms in semiconductors, a leading platform for the generation of quantum light, would therefore provide a new avenue for the development of entangled photon pair sources. Here we demonstrate a radiative cascade from the decay of a biexciton at an impurity-atom complex in a ZnSe quantum well.

View Article and Find Full Text PDF

Isolated impurity states in epitaxially grown semiconductor systems possess important radiative features such as distinct wavelength emission with a very short radiative lifetime and low inhomogeneous broadening, which make them promising for the generation of indistinguishable single photons. In this study, we investigate chlorine-doped ZnSe/ZnMgSe quantum well (QW) nanopillar (NP) structures as a highly efficient solid-state single-photon source operating at cryogenic temperatures. We show that single photons are generated due to the radiative recombination of excitons bound to neutral Cl atoms in ZnSe QW and the energy of the emitted photon can be tuned from about 2.

View Article and Find Full Text PDF

Shallow donors in ZnO are promising candidates for photon-mediated quantum technologies. Utilizing the indium donor, we show that favorable donor-bound exciton optical and electron spin properties are retained in isolated ZnO nanowires. The inhomogeneous optical line width of single nanowires (60 GHz) is within a factor of 2 of bulk single-crystalline ZnO.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!