Trap-State Suppression and Improved Charge Transport in PbS Quantum Dot Solar Cells with Synergistic Mixed-Ligand Treatments.
Small
; 13(21)2017 06.
Article
em En
| MEDLINE
| ID: mdl-28401651
ABSTRACT
The power conversion efficiency of colloidal PbS-quantum-dot (QD)-based solar cells is significantly hampered by lower-than-expected open circuit voltage (VOC ). The VOC deficit is considerably higher in QD-based solar cells compared to other types of existing solar cells due to in-gap trap-induced bulk recombination of photogenerated carriers. Here, this study reports a ligand exchange procedure based on a mixture of zinc iodide and 3-mercaptopropyonic acid to reduce the VOC deficit without compromising the high current density. This layer-by-layer solid state ligand exchange treatment enhances the photovoltaic performance from 6.62 to 9.92% with a significant improvement in VOC from 0.58 to 0.66 V. This study further employs optoelectronic characterization, X-ray photoelectron spectroscopy, and photoluminescence spectroscopy to understand the origin of VOC improvement. The mixed-ligand treatment reduces the sub-bandgap traps and significantly reduces bulk recombination in the devices.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
Small
Assunto da revista:
ENGENHARIA BIOMEDICA
Ano de publicação:
2017
Tipo de documento:
Article
País de afiliação:
Espanha