Redshifting and broadening of quantum-well infrared photodetector's response via impurity-free vacancy disordering

Deepak Sengupta, Vikram Jandhyala, Sangsig Kim, Weich Fang, Jay Malin, Peter Apostolakis, Kwong Chi Hseih, Yia Chung Chang, Shun Lien Chuang, Sumith Bandara, Sarath Gunapala, Milton Feng, Eric Michielssen, Greg Stillman

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17 Citations (Scopus)

Abstract

The partial intermixing of the well and barrier materials offers unique opportunities to shift locally the bandgap of quantum-well (QW) structures. We have demonstrated red-shifting and broadening of the wavelength responses of boundto-continuum GaAs and InP based quantum-well infrared photodetectors (QWIP's) after growth via impurity-free vacancy disordering (IFVD). A comprehensive set of experiments is conducted on QWIP's fabricated from both as-grown and multiple-quantum-well (MQW) structures. Compared to the as-grown detector, the peak spectral responses of the disordered detectors were shifted to longer wavelengths. The peak absolute response of the disordered GaAs based QWIP is lower by almost a factor of four. However, the responsivity characteristics of the disordered InP based QWIP show no major degradation. In general, with the spectral broadening taken into account, the overall performance of the disordered QWIP's has not dropped significantly. Thus, the postgrowth control of the QW composition profiles by impurity-free vacancy disordering offers unique opportunities to fine tune various aspects of a photodetector's response. Theoretical calculations of the absorption coefficient spectrum are in excellent agreement with the experimental data.

Original languageEnglish
Pages (from-to)746-757
Number of pages12
JournalIEEE Journal on Selected Topics in Quantum Electronics
Volume4
Issue number4
DOIs
Publication statusPublished - 1998 Jul 1
Externally publishedYes

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Keywords

  • Absolute response
  • Dark current characteristics
  • Focal plane array
  • Impurity-free vacancy disordering
  • Peak response wavelength
  • Quantum efficiency
  • Quantum-well infrared photodetectors
  • Rapid thermal annealing
  • Red shift

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Atomic and Molecular Physics, and Optics

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