Atomic layer deposited Al2O3 passivation of type II InAs/GaSb superlattice photodetectors

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Salihoglu O., Muti A., Kutluer K., Tansel T., TURAN R., KOCABAŞ C., ...More

JOURNAL OF APPLIED PHYSICS, vol.111, no.7, 2012 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 111 Issue: 7
  • Publication Date: 2012
  • Doi Number: 10.1063/1.3702567
  • Journal Name: JOURNAL OF APPLIED PHYSICS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Middle East Technical University Affiliated: Yes

Abstract

Taking advantage of the favorable Gibbs free energies, atomic layer deposited (ALD) aluminum oxide (Al2O3) was used as a novel approach for passivation of type II InAs/GaSb superlattice (SL) midwave infrared (MWIR) single pixel photodetectors in a self cleaning process (lambda(cut-off) similar to 5.1 mu m). Al2O3 passivated and unpassivated diodes were compared for their electrical and optical performances. For passivated diodes, the dark current density was improved by an order of magnitude at 77 K. The zero bias responsivity and detectivity was 1.33 A/W and 1.9 x 10(13) Jones, respectively at 4 mu m and 77 K. Quantum efficiency (QE) was determined as %41 for these detectors. This conformal passivation technique is promising for focal plane array (FPA) applications. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.3702567]