Bulk photovoltaic effect in hexagonal LuMnO3 single crystals

Hexagonal manganites, such as h-LuMnO3, are ferroelectric and have a narrow electronic band gap of ≈1.5eV. Here we report on the photoresponse of h-LuMnO3 single crystals. It is found that the short circuit photocurrent density (Jsc) and the open circuit voltage (Voc) are dependent on the direction...

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Detalles Bibliográficos
Autores: Sheng, Yunwei, Fina, Ignasi, Gospodinov, Marin, Schankler, Aaron M., Rappe, Andrew M., Fontcuberta, Josep
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2021
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/264296
Acceso en línea:http://hdl.handle.net/10261/264296
https://api.elsevier.com/content/abstract/scopus_id/85121112233
Access Level:acceso abierto
Palabra clave:Ferroelectricity
Ferroelectrics
Photogalvanic effect
Photovoltaic absorbers
Photovoltaic effect
Descripción
Sumario:Hexagonal manganites, such as h-LuMnO3, are ferroelectric and have a narrow electronic band gap of ≈1.5eV. Here we report on the photoresponse of h-LuMnO3 single crystals. It is found that the short circuit photocurrent density (Jsc) and the open circuit voltage (Voc) are dependent on the direction of the polarization plane of a linearly polarized impinging light. Its angular dependence indicates the contribution of bulk photovoltaic effect to the short circuit photocurrent. It is also observed that a switchable drift photocurrent, originating from the depoling field of the ferroelectric and thus tunable (<10%) by its polarization direction, also contributes to Jsc. Although its presence precludes accurate determination of the bulk photovoltaic tensor elements and Glass coefficients, some bounds can be established. The Glass coefficients are found to be significantly larger than those obtained in BiFeO3. We argue that the smaller band gap of h-LuMnO3, its distinctive bipyramidal crystal field, and electronic configuration (3d4 vs 3d5), account for the difference and suggest a path towards ferroelectrics of higher photoconversion efficiency.