Large-format voltage-tunable dual-band quantum-well infrared photodetector focal plane array for third-generation thermal imagers

Eker S. U., Kaldirim M., Arslan Y., BEŞİKCİ C.

IEEE ELECTRON DEVICE LETTERS, vol.29, no.10, pp.1121-1123, 2008 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 29 Issue: 10
  • Publication Date: 2008
  • Doi Number: 10.1109/led.2008.2002538
  • Journal Name: IEEE ELECTRON DEVICE LETTERS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.1121-1123
  • Keywords: dual-band infrared detector, focal plane array (FPA), WAVELENGTH
  • Middle East Technical University Affiliated: Yes

Abstract

We report a large-format (640 x 512) voltage-tunable quantum-well (QW) infrared photodetector focal plane array (FPA) for dual-band imaging in the mid- and long-wavelength infrared (MWIR and LWIR) bands. Voltage-tunable spectral response has been achieved through a series connection of eight-well MWIR AlGaAs-InGaAs and 16-well LWIR AlGaAs-GaAs QW stacks grown by molecular beam epitaxy on GaAs substrate. The peak responsivity wavelength of the detectors is shifted from 4.8 to 8.4 mu m as the bias is increased within the limit applicable by commercial read-out integrated circuits. The FPA with MWIR and LWIR cutoff wavelengths of 5.1 and 8.9 mu m provides noise equivalent temperature differences of 20 and 32 mK (f/1.5) in these bands, respectively. The results are very encouraging for the development of low-cost large-format dual-band MWIR/LWIR FPA technology.