Stoichiometric dependence of TiOx as a cathode modifier on band alignment of polymer solar cells
| Autor: | Chun-Wei Chen, Yun Chieh Yeh, Chao Chuan Wu, Shao Sian Li, Pai Chia Kuo, Teng Wei Shao |
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| Rok vydání: | 2014 |
| Předmět: |
Materials science
Renewable Energy Sustainability and the Environment Photovoltaic system Nanotechnology Cathode Polymer solar cell Surfaces Coatings and Films Electronic Optical and Magnetic Materials law.invention Dielectric spectroscopy Titanium oxide Photoactive layer Chemical engineering law Layer (electronics) Stoichiometry |
| Zdroj: | Solar Energy Materials and Solar Cells. 125:233-238 |
| ISSN: | 0927-0248 |
| Popis: | In this study, we systematically investigated the stoichiometric dependence of titanium oxide (TiOx, x=1.56–1.93) as a cathode modifier on the device performance of polymer solar cells. Electronic structures of the synthesized TiOx modifier layers were controlled by tuning the compositions of various O/Ti ratios. The effective cathode work-functions and the corresponding device performances of polymer solar cells are systematically changed as a result of inserting the TiOx modification layers. Interfacial modification of the Al cathode with a low O/Ti ratio of TiOx layer yields the best performing photovoltaic device as a result of a largest built-in potential. The correlation of power conversion efficiencies and carrier dynamics of these devices by inserting various TiOx modification layer is further examined by using the Mott-Schottky analysis and the impedance spectroscopy technique. The consistent result shows an enhanced carrier collection efficiency and a reduced charge recombination rate of the device via adequate band alignment between the photoactive layer and the cathode using the TiOx modification layer with an optimized O/Ti ratio. |
| Databáze: | OpenAIRE |
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