Growth of p-type GaAs∕AlGaAs(111) quantum well infrared photodetector using solid source molecular-beam epitaxy
Zhang, Dao Hua
Yoon, Soon Fatt
Yuan, K. H.
Date of Issue2005
School of Electrical and Electronic Engineering
Department of Physics, Naval Postgraduate School, Monterey, California
A p-type GaAs/AlGaAs multi-quantum-well infrared photodetector(QWIP) was fabricated on a GaAs (111)A substrate by molecular-beam epitaxy using silicon as dopant. The same structure was also grown on a GaAs (100) wafer simultaneously to compare the material and structural properties. It was found that Si acts as a p-type dopant in the GaAs (111)A sample while it is -type in the GaAs (100) counterpart. The growth rate was found to be appreciably enhanced for GaAs (111)A compared with that of GaAs (100) orientation, while the Al composition in the barriers was found to be 20% smaller for a (111) orientation which results in a smaller barrier height. A peak responsivity of 1mA/W with a relatively wide wavelength response (∆𝞴?� /𝞴?�p ~53%) was observed for the GaAs (111)A QWIP, mainly due to the location of the excited state far above the barrier. The photoresponse also showed a relatively strong normal incident absorption probably originating from the mixing of the conduction and valence Bloch states. The optimization of the quantum well parameters should further enhance the responsivity of this p-type QWIP with Si as dopant species.
DRNTU::Engineering::Electrical and electronic engineering
Journal of applied physics
© 2005 American Institute of Physics. This paper was published in Journal of Applied Physics and is made available as an electronic reprint (preprint) with permission of American Institute of Physics. The paper can be found at the following official DOI: [http://dx.doi.org/10.1063/1.2034652]. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper is prohibited and is subject to penalties under law.