Lateral absorption measurements of InAs/GaAs quantum dots stacks: Potential as intermediate band material for high efficiency solar cells
| Autor: | Teresa Ben, Enrique Cánovas, Sergio I. Molina, Antonio Luque, Ana M. Sanchez, Antonio Martí, Colin Stanley, C.D. Farmer |
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| Rok vydání: | 2010 |
| Předmět: |
Work (thermodynamics)
Materials science Photon Characterization 02 engineering and technology 7. Clean energy 01 natural sciences Absorption Intermediate band Energy(all) Path length 0103 physical sciences Absorption (electromagnetic radiation) Intermediate band solar cell 010302 applied physics Quantum dots business.industry Física 021001 nanoscience & nanotechnology Characterization (materials science) Multiple exciton generation Quantum dot Attenuation coefficient Optoelectronics 0210 nano-technology business |
| Zdroj: | Energy Procedia-Proceedings of Inorganic and Nanostructured Photovoltaics (E-MRS 2009 Symposium B) | The E-MRS 2009 Spring Meeting, Symposium B | 08/06/2009-12/06/2009 | Strasbourg, Francia Archivo Digital UPM Universidad Politécnica de Madrid |
| ISSN: | 1876-6102 |
| DOI: | 10.1016/j.egypro.2010.07.006 |
| Popis: | Prototypes based on InAs/GaAs QDs have been manufactured in order to realize the theoretically predicted high efficiency intermediate band solar cells (IBSCs). Unfortunately, until now, these prototypes have not yet demonstrated the expected increase in efficiency when compared with reference samples without IB material. One of the main arguments explaining this performance is the weak photon absorption in the QD-IB material, arising from a low density of QDs. In this work, we have analyzed the absorption coefficient of the IB material by developing a sample in an optical wave-guided configuration. This configuration allows us to illuminate the QDs laterally, increasing the path length for photon absorption. Using a multi-section metal contact device design, we were able to measure an absorption coefficient of ∼100 cm−1 around the band edge (∼1 eV ) defined by the V B♦IB transition in InAs/GaAs QD-IB materials. This figure, and its influence on the IBSC concept, is analyzed for this system. |
| Databáze: | OpenAIRE |
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