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Proceedings Paper

Low dark current N structure superlattice MWIR photodetectors
Author(s): Omer Salihoglu; Abdullah Muti; Rasit Turan; Yuksel Ergun; Atilla Aydinli
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Paper Abstract

Commercially available read out integrated circuits (ROICs) require the FPA to have high dynamic resistance area product at zero bias (R0A) which is directly related to dark current of the detector. Dark current arises from bulk and surface contributions. Recent band structure engineering studies significantly suppressed the bulk contribution of the type-II superlattice infrared photodetectors (N structure, M structure, W structure). In this letter, we will present improved dark current results for unipolar barrier complex supercell superlattice system which is called as “N structure”. The unique electronic band structure of the N structure increases electron-hole overlap under bias, significantly. N structure aims to improve absorption by manipulating electron and hole wavefunctions that are spatially separated in T2SLs, increasing the absorption while decreasing the dark current. In order to engineer the wavefunctions, we introduce a thin AlSb layer between InAs and GaSb layers in the growth direction which also acts as a unipolar electron barrier. Despite the difficulty of perfect lattice matching of InAs and AlSb, such a design is expected to reduce dark current. Experiments were carried out on Single pixel with mesa sizes of 100 × 100 – 700 × 700 μm photodiodes. Temperature dependent dark current with corresponding R0A resistance values are reported.

Paper Details

Date Published: 24 June 2014
PDF: 6 pages
Proc. SPIE 9070, Infrared Technology and Applications XL, 907012 (24 June 2014); doi: 10.1117/12.2050316
Show Author Affiliations
Omer Salihoglu, TÜBİTAK MAM (Turkey)
Abdullah Muti, Bilkent Univ. (Turkey)
Rasit Turan, Middle East Technical Univ. (Turkey)
Yuksel Ergun, Anadolu Univ. (Turkey)
Atilla Aydinli, Bilkent Univ. (Turkey)

Published in SPIE Proceedings Vol. 9070:
Infrared Technology and Applications XL
Bjørn F. Andresen; Gabor F. Fulop; Charles M. Hanson; Paul R. Norton, Editor(s)

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