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oai:figshare.com:article/34050156 2026-10-01T18:05:09Z category_1 category_4 category_146 category_915 category_873 category_39 category_734 category_64 category_133 portal_63 item_type_6 month_year_10_2026

Charge-Transfer States Enhance Triplet Yield in Silicon Quantum Dot-Pyrene Hybrid Nanostructure Maryam Baraazandeh (23838008) Mandefro Y. Teferi (5262356) Alex Berzansky (15403262) Sachini Rodrigo (9115178) Luisa Whittaker-Brooks (1332174) Jens Niklas (805862) Oleg G. Poluektov (1234986) Yawei Liu (171534) Ming Lee Tang (1892590) Zihao Xu (1661440) Biophysics Biochemistry Space Science Physical Sciences not elsewhere classified Chemical Sciences not elsewhere classified Ecology Biological Sciences not elsewhere classified Cancer Plant Biology utilize incoherent sub though quantum dots strong electronic coupling silicon quantum dot overcoming unfavorable kinetics bound pyrene acceptors various trap states upconversion quantum yield transient absorption spectroscopies linked si qd transient hole si qd molecular states based upconversion tunable bandgaps transfer intermediate theoretical maximum si qds qds ), hybrid achieved highest reported facilitating hole energy conversion electron transfer effective strategy depleting pathways cyclic voltammetry conjugated bridges competes effectively bandgap photons attached pyrenes 7 ns 50 %) Photon upconversion based on triplet–triplet annihilation can utilize incoherent sub-bandgap photons for energy conversion and photocatalysis. Though quantum dots (QDs), with their tunable bandgaps, make attractive triplet photosensitizers, energy transfer must compete with other exciton-depleting pathways that stem from various trap states. Here, we show that strong electronic coupling can be introduced through conjugated bridges between Si QDs and surface-bound pyrene acceptors by creating a transient hole-transfer intermediate from Si to attached pyrenes, which enhances triplet energy transfer. The hybrid achieved an upconversion quantum yield of 10.8% (with a theoretical maximum of 50%) with DPA as the emitter, which is the highest reported for Si QD-based upconversion. By using a combination of cyclic voltammetry, time-resolved electron paramagnetic resonance, and transient absorption spectroscopies, we show that the alkyne and vinyl bridges hybridize QD and molecular states, facilitating hole-then-electron transfer that competes effectively with exciton quenching. Specifically, the alkyne-linked Si QD: AP hybrid exhibits hole transfer with a time constant of 1.7 ns and an efficiency of 27%, highlighting linker conjugation as an effective strategy for overcoming unfavorable kinetics and energetics. 2026-10-01T00:00:00Z Text Journal contribution 10.1021/jacs.6c15357.s001 https://figshare.com/articles/journal_contribution/Charge-Transfer_States_Enhance_Triplet_Yield_in_Silicon_Quantum_Dot-Pyrene_Hybrid_Nanostructure/34050156 CC BY-NC 4.0