Topologically protected photovoltaics in Bi nanoribbons

Photovoltaic efficiency in solar cells is hindered bymany unwanted effects. Radiative channels (emission of photons)sometimes mediated by nonradiative ones (emission of phonons)are principally responsible for the decrease in exciton populationbefore charge separation can take place. One such mechani...

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Detalhes bibliográficos
Autores: Uría Álvarez, Alejandro José, Palacios Burgos, Juan José
Formato: artículo
Fecha de publicación:2024
País:España
Recursos:Universidad Autónoma de Madrid
Repositorio:Biblos-e Archivo. Repositorio Institucional de la UAM
Idioma:inglés
OAI Identifier:oai:repositorio.uam.es:10486/713012
Acesso em linha:http://hdl.handle.net/10486/713012
https://dx.doi.org/10.1021/acs.nanolett.4c01277
Access Level:acceso abierto
Palavra-chave:Photovoltaics
Topological insulator
Exciton
Optics
Two-Dimensional Materials
Física
Descrição
Resumo:Photovoltaic efficiency in solar cells is hindered bymany unwanted effects. Radiative channels (emission of photons)sometimes mediated by nonradiative ones (emission of phonons)are principally responsible for the decrease in exciton populationbefore charge separation can take place. One such mechanism iselectron−hole recombination at surfaces or defects where the in-gap edge states serve as the nonradiative channels. In topologicalinsulators (TIs), which are rarely explored from an optoelectronicsstandpoint, we show that their characteristic surface statesconstitute a nonradiative decay channel that can be exploited togenerate a protected photovoltaic current. Focusing on two-dimensional TIs, and specifically for illustration purposes on aBi(111) monolayer, we obtain the transition rates from the bulkexcitons to the edge states. By breaking the appropriate symmetries of the system, one can induce an edge charge accumulation andedge currents under illumination, demonstrating the potential of TI nanoribbons for photovoltaics