Design of Band Engineered HgCdTe nBn Detectors for MWIR and LWIR Applications

Author

Akhavan, Nima Dehdashti ; Jolley, Gregory ; Umana-Membreno, Gilberto A. ; Antoszewski, Jarek ; Faraone, Lorenzo

Author_Institution

Dept. of Electr., Univ. of Western Australia, Crawley, WA, Australia

Volume

62

Issue

3

fYear

2015

fDate

Mar-15

Firstpage

722

Lastpage

728

Abstract

In this paper, we present a theoretical study of mercury cadmium telluride (HgCdTe)-based unipolar n-type/barrier/n-type (nBn) infrared (IR) detector structures for midwave IR and longwave IR spectral bands. To achieve the ultimate performance of nBn detectors, a bandgap engineering method is proposed to remove the undesirable valence band discontinuity that is currently limiting the performance of conventional HgCdTe nBn detectors. Our proposed band engineering method relies on simultaneous grading of the barrier composition and doping density profiles, leading to efficient elimination of the valence band discontinuity. This allows the detector to operate at |V_bias| <;50 mV, rendering all tunneling-related dark current components insignificant and allowing the detector to achieve the maximum possible diffusion current limited performance.

Keywords

II-VI semiconductors; cadmium compounds; diffusion; energy gap; infrared detectors; mercury compounds; photodetectors; semiconductor doping; valence bands; HgCdTe; LWIR applications; MWIR applications; band engineered HgCdTe nBn detectors; barrier composition; diffusion current limited performance; doping density profiles; longwave IR spectral bands; midwave IR spectral bands; theoretical study; tunneling-related dark current; unipolar n-type/barrier/n-type infrared detector structures; valence band discontinuity; Absorption; Dark current; Detectors; Doping; Mathematical model; Performance evaluation; Photonic band gap; Band discontinuity; doping modulation; infrared (IR) detectors; mercury cadmium telluride (HgCdTe); n-type/barrier/n-type (nBn); unipolar barrier; unipolar barrier.;

fLanguage

English

Journal_Title

Electron Devices, IEEE Transactions on

Publisher

ieee

ISSN

0018-9383

Type

jour

DOI

10.1109/TED.2015.2389229

Filename

7027177