| Autor: |
Cinquanta E; Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche, Piazza Leonardo da Vinci 32, Milano 20133, Italy., Sardar S; Center for Nano Science and Technology @PoliMi, Istituto Italiano di Tecnologia, Via Giovanni Pascoli 70, Milano 20133, Italy., Huey WLB; Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States., Vozzi C; Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche, Piazza Leonardo da Vinci 32, Milano 20133, Italy., Goldberger JE; Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States., D'Andrea C; Center for Nano Science and Technology @PoliMi, Istituto Italiano di Tecnologia, Via Giovanni Pascoli 70, Milano 20133, Italy.; Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, Milano 20133, Italy., Gadermaier C; Center for Nano Science and Technology @PoliMi, Istituto Italiano di Tecnologia, Via Giovanni Pascoli 70, Milano 20133, Italy.; Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, Milano 20133, Italy. |
| Abstrakt: |
Methyl-substituted germanane is an emerging material that has been proposed for novel applications in optoelectronics, photoelectrocatalysis, and biosensors. It is a two-dimensional semiconductor with a strong above-gap fluorescence associated with water intercalation. Here, we use time-resolved photoluminescence spectroscopy to understand the mechanism causing this fluorescence. We show that it originates from two distinct exciton populations. Both populations recombine exponentially, accompanied by the thermally activated transfer of exciton population from the shorter- to the longer-lived type. The two exciton populations involve different electronic levels and couple to different phonons. The longer-lived type of exciton migrates within the disordered energy landscape of localized recombination centers. These outcomes shed light on the fundamental optical and electronic properties of functionalized germanane, enabling the groundwork for future applications in optoelectronics, light harvesting, and sensing. |
