Role of the wetting layer in the enhanced responsivity of InAs/GaAsSb quantum dot infrared photodetectors
| Autor: | J. M. Llorens, Adrian Hierro, Álvaro Guzmán, Kenji Yamamoto, JM José Maria Ulloa |
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| Přispěvatelé: | Ministerio de Economía y Competitividad (España), Comunidad de Madrid |
| Rok vydání: | 2015 |
| Předmět: |
010302 applied physics
Photocurrent Telecomunicaciones Materials science Physics and Astronomy (miscellaneous) business.industry Photoconductivity Photodetector 02 engineering and technology 021001 nanoscience & nanotechnology 01 natural sciences Gallium arsenide Responsivity chemistry.chemical_compound chemistry Quantum dot 0103 physical sciences Optoelectronics Electrónica Wetting 0210 nano-technology business Wetting layer |
| Zdroj: | Digital.CSIC. Repositorio Institucional del CSIC instname Applied Physics Letters, ISSN 0003-6951, 2015, Vol. 107, No. 1 Archivo Digital UPM Universidad Politécnica de Madrid |
| Popis: | © 2015 AIP Publishing LLC. InAs/GaAs1−xSbx Quantum Dot (QD) infrared photodetectors are analyzed by photocurrent spectroscopy. We observe that the integrated responsivity of the devices is improved with the increasing Sb mole fraction in the capping layer, up to 4.2 times for x=17%. Since the QD layers are not vertically aligned, the vertical transport of the carriers photogenerated within the QDs takes place mainly through the bulk material and the wetting layer of the additional QD regions. The lower thickness of the wetting layer for high Sb contents results in a reduced capture probability of the photocarriers, thus increasing the photoconductive gain and hence, the responsivity of the device. The growth of not vertically aligned consecutive QD layers with a thinner wetting layer opens a possibility to improve the performance of quantum dot infrared photodetectors. This work has been supported by the Comunidad de Madrid through Project No. S2013/MAE-2780 and by the Spanish Ministry of Economy and Competitiveness through Project Nos. MAT2013-47102-C2-2-R, ENE2012-37804-C02-02, and AIC-B-2011-0806. |
| Databáze: | OpenAIRE |
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