Efficient 2D to 0D Energy Transfer in HgTe Nanoplatelet-Quantum Dot Heterostructures through High-Speed Exciton Diffusion

Stephanie M Tenney; Lauren A Tan; Xuanheng Tan; Mikayla L Sonnleitner; Belle Coffey; Jillian A Williams; Ricky Ronquillo; Timothy L Atallah; Tasnim Ahmed; Justin R Caram

doi:10.1021/acs.jpclett.3c02168

Efficient 2D to 0D Energy Transfer in HgTe Nanoplatelet-Quantum Dot Heterostructures through High-Speed Exciton Diffusion

J Phys Chem Lett. 2023 Oct 26;14(42):9456-9463. doi: 10.1021/acs.jpclett.3c02168. Epub 2023 Oct 13.

Affiliations

¹ Department of Chemistry and Biochemistry, University of California, Los Angeles, 607 Charles E. Young Drive, Los Angeles, California 90095-1569, United States.
² Department of Chemistry and Biochemistry, Denison University, 500 West Loop, Granville, Ohio 43023, United States.

PMID: 37830914
DOI: 10.1021/acs.jpclett.3c02168

Abstract

Large area absorbers with localized defect emission are of interest for energy concentration via the antenna effect. Transfer between 2D and 0D quantum-confined structures is advantageous as it affords maximal lateral area antennas with continuously tunable emission. We report the quantum efficiency of energy transfer in in situ grown HgTe nanoplatelet (NPL)/quantum dot (QD) heterostructures to be near unity (>85%), while energy transfer in separately synthesized and well separated solutions of HgTe NPLs to QDs only reaches 47 ± 11% at considerably higher QD concentrations. Using Kinetic Monte Carlo simulations, we estimate an exciton diffusion constant of 1-10 cm²/s in HgTe NPLs, the same magnitude as that of 2D semiconductors. We also simulate in-solution energy transfer between NPLs and QDs, recovering an R^-4 dependence consistent with 2D-0D near-field energy transfer even in randomly distributed NPL/QD mixtures. This highlights the advantage of NPLs 2D morphology and the efficiency of NPL/QD heterostructures and mixtures for energy harvesting.