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El cribado en líquidos cristalinos protege a los portadores energéticos en las perovskitas híbridas
Haiming Zhu1, Kiyoshi Miyata1, Yongping Fu2
1Department of Chemistry, Columbia University, New York, NY 10027, USA.
Science (New York, N.Y.)
|October 7, 2016
Resumen
Las perovskitas híbridas protegen a los portadores energéticos a través del cribado dinámico, similar a los movimientos moleculares similares a los líquidos. Este mecanismo, observado en perovskitas específicas, puede permitir celdas solares de soporte caliente eficientes.
Área de la Ciencia:
- Ciencias de los materiales
- Física del estado sólido
- Las instalaciones fotovoltaicas
Sus antecedentes:
- Las perovskitas híbridas de haluro de plomo muestran excelentes propiedades de transporte a pesar del trastorno inherente.
- El mecanismo que protege a los portadores de la dispersión por defectos y fonones sigue sin estar claro.
Objetivo del estudio:
- Investigar el mecanismo de protección del portador en las perovskitas híbridas de haluro de plomo.
- Para comparar la dinámica del portador en el bromuro de plomo de metilamonio (CH 3 NH 3 PbBr 3), el bromuro de plomo de formamidinio (CH ((NH 2) 2 PbBr 3) y el bromuro de plomo de cesio (CsPbBr 3).
Principales métodos:
- Observación de la emisión de fluorescencia caliente de los portadores energéticos.
- Espectroscopia con resolución de tiempo para medir la vida útil del portador (~ 10 picosegundos).
- Análisis de correlación entre la dinámica del portador y los movimientos de reorientación molecular.
Principales resultados:
- Se observó fluorescencia en caliente en CH 3 NH 3 PbBr 3 y CH ((NH 2) 2 PbBr 3, pero no en CsPbBr 3.
- La fluorescencia caliente se correlaciona con movimientos de reorientación moleculares similares a los líquidos.
- La evidencia sugiere que el cribado dinámico (solvación o gran formación de polarones) protege a los portadores energéticos.
Conclusiones:
- El cribado dinámico protege a los portadores energéticos en las perovskitas híbridas en escalas de tiempo ultrarrápidas.
- Es probable que este mecanismo de protección también esté presente para los transportistas de borde de banda.
- Los soportes energéticos de larga duración podrían allanar el camino para las células solares de soporte caliente avanzadas que superan los límites teóricos de eficiencia.
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