Optimization of charge transfer and transport processes at the CdSe quantum dots/TiO2 nanorod interface by TiO2 interlayer passivation
| Autor: | Manuel Alejandro Triana, Marina E. Rincón, Oscar A. Jaramillo-Quintero |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Anatase
Materials science Thin layers Acoustics and Ultrasonics Passivation business.industry Surface photovoltage Nanotechnology 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences 0104 chemical sciences Surfaces Coatings and Films Electronic Optical and Magnetic Materials Dielectric spectroscopy Quantum dot Optoelectronics Nanorod Thin film 0210 nano-technology business |
| Zdroj: | Journal of Physics D: Applied Physics. 50:235305 |
| ISSN: | 1361-6463 0022-3727 |
| DOI: | 10.1088/1361-6463/aa6e7c |
| Popis: | Surface trap states hinder charge transfer and transport properties in TiO2 nanorods (NRs), limiting its application on optoelectronic devices. Here, we study the interfacial processes between rutile TiO2 NR and CdSe quantum dots (QDs) using TiO2 interlayer passivation treatments. Anatase or rutile TiO2 thin layers were deposited on an NR surface by two wet-chemical deposition treatments. Reduced interfacial charge recombination between NRs and CdSe QDs was observed by electrochemical impedance spectroscopy with the introduction of TiO2 thin film interlayers compared to bare TiO2 NRs. These results can be ascribed to in-gap trap state passivation of the TiO2 NR surface, which led to an increase in open circuit voltage. Moreover, the rutile thin layer was more efficient than anatase to promote a higher photo-excited electron transfer from CdSe QDs to TiO2 NRs due to a large driving force for charge injection, as confirmed by surface photovoltage spectroscopy. |
| Databáze: | OpenAIRE |
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