Theoretical study of quantum well infrared photodetectors with asymmetric well and barrier structures for broadband photodetection

• Main Authors: Huang, Z. M., Liu, W., Zhang, Dao Hua, Fan, Weijun
• Other Authors: School of Electrical and Electronic Engineering
• Format: Article
• Language: English
• Published: 2013
• Subjects: DRNTU::Engineering::Electrical and electronic engineering
• Online Access: https://hdl.handle.net/10356/100806; http://hdl.handle.net/10220/18166
• Institution: Nanyang Technological University

The n-type InGaAs/AlxGa1−xAs quantum well infrared photodetector QWIP with asymmetric graded barriers for broadband detection has been investigated theoretically based on the eight-band k·p model. It is found that the intersubband transitions from the ground state to all bound and continuum excited states contribute to the overall absorption and the bound-to-continuum B-to-C transitions dominate. The superposition of the bound-to-bound and B-to-C transitions results in a broad detection bandwidth, and both the detected wavelength and bandwidth can be tuned by the applied voltage. The analysis method is also applicable to the GaAs/ InxGa1−xAs/ InyGa1−yAs QWIP with step quantum wells. The calculated results are consistent with the reported experimental observations.