Hot carrier extraction from multilayer graphene
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| Autores: | , , , , |
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| Formato: | artículo original |
| Fecha de Publicación: | 2016 |
| Descripción: | Hot carriers in semiconductor or metal nanostructures are relevant, for instance, to enhance the activity of oxide-supported metal catalysts or to achieve efficient photodetection using ultrathin semiconductor layers. Moreover, rapid collection of photoexcited hot carriers can improve the efficiency of solar cells, with a theoretical maximum of 85%. Because of the long lifetime of secondary excited electrons, graphene is an especially promising two-dimensional material to harness hot carriers for solar-to-electricity conversion. However, the photoresponse of thus far realized graphene photoelectric devices is mainly governed by thermal effects, which yield only a very small photovoltage. Here, we report a Gr–TiOx–Ti heterostructure wherein the photovoltaic effect is predominant. By doping the graphene, the open circuit voltage reaches values up to 0.30 V, 2 orders of magnitude larger than for devices relying upon the thermoelectric effect. The photocurrent turned out to be limited by trap states in the few-nanometer-thick TiOx layer. Our findings represent a first valuable step toward the integration of graphene into third-generation solar cells based upon hot carrier extraction. |
| País: | Kérwá |
| Institución: | Universidad de Costa Rica |
| Repositorio: | Kérwá |
| OAI Identifier: | oai:kerwa.ucr.ac.cr:10669/86059 |
| Acceso en línea: | https://pubs.acs.org/doi/full/10.1021/acs.nanolett.6b02354 https://hdl.handle.net/10669/86059 |
| Palabra clave: | Hot carrier Graphene Photovoltaic devices Two-dimensional (2D) materials F4-TCNQ Gr−TiOx−Ti heterostructures |