Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Long-wavelength infrared quantum-dot based interband photodetectors
KTH, School of Information and Communication Technology (ICT), Integrated Devices and Circuits.
KTH, School of Information and Communication Technology (ICT), Integrated Devices and Circuits.
KTH, School of Information and Communication Technology (ICT), Optics and Photonics (Closed 20120101), Photonics (Closed 20120101).
KTH, School of Information and Communication Technology (ICT), Integrated Devices and Circuits.ORCID iD: 0000-0002-8760-1137
Show others and affiliations
2011 (English)In: Infrared physics & technology, ISSN 1350-4495, E-ISSN 1879-0275, Vol. 54, no 3, 287-291 p.Article in journal (Refereed) Published
Abstract [en]

We report on the design and fabrication of (Al)GaAs(Sb)/InAs tensile strained quantum-dot (QD) based detector material for thermal infrared imaging applications in the long-wavelength infrared (LWIR) regime. The detection is based on transitions between confined dot states and continuum states in a type-II band lineup, and we therefore refer to it as a dot-to-bulk (D2B) infrared photodetector with expected benefits including long carrier lifetime due to the type-II band alignment, suppressed Shockley-Read-Hall generation-recombination due to the relatively large-bandgap matrix material, inhibited Auger recombination processes due to the tensile strain and epitaxial simplicity. Metal-organic vapor-phase epitaxy was used to grow multiple (Al)GaAs(Sb) QD layers on InAs substrates at different QD nominal thicknesses, compositions, doping conditions and multilayer periods, and the material was characterized using atomic force and transmission electron microscopy, and Fourier-transform infrared absorption spectroscopy. Dot densities up to 1 x 10(11) cm(-2), 1 x 10(12) cm(-2) and 3 x 10(10) cm(-2) were measured for GaAs, AlGaAs and GaAsSb QDs, respectively. Strong absorption in GaAs, AlGaAs and GaAsSb multilayer QD samples was observed in the wavelength range 6-12 mu m. From the wavelength shift in the spectral absorption for samples with varying QD thickness and composition it is believed that the absorption is due to an intra- valance band transition. From this it is possible to estimate the type-II inter-band transition wavelength, thereby suggesting that (Al)GaAs(Sb) QD/InAs heterostructures are suitable candidates for LWIR detection and imaging.

Place, publisher, year, edition, pages
2011. Vol. 54, no 3, 287-291 p.
Keyword [en]
Photodetector, LWIR, QD, MOVPE
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
URN: urn:nbn:se:kth:diva-34662DOI: 10.1016/j.infrared.2010.12.031ISI: 000290973200028Scopus ID: 2-s2.0-79955029475OAI: oai:DiVA.org:kth-34662DiVA: diva2:425267
Note

QC 20110621 Ingår i konferens: International Conference on the Quantum Structure Infrared Photodector (QSIP), Istanbul, TURKEY, AUG 15-20, 2010

Available from: 2011-06-21 Created: 2011-06-13 Last updated: 2017-12-11Bibliographically approved
In thesis
1. Type-II interband quantum dot photodetectors
Open this publication in new window or tab >>Type-II interband quantum dot photodetectors
2013 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Photon detectors based on single-crystalline materials are of great interest for high performance imaging applications due to their low noise and fast response. The major detector materials for sensing in the long-wavelength infrared (LWIR) band (8-14 µm) are currently HgCdTe (MCT) and AlGaAs/GaAs quantum wells (QW) used in intraband-based quantum-well infrared photodetectors (QWIPs). These either suffer from compositional variations that are detrimental to the system performance as in the case of MCT, or, have an efficient dark current generation mechanism that limits the operating temperature as for QWIPs. The need for increased on-wafer uniformity and elevated operating temperatures has resulted in the development of various alternative approaches, such as type-II strained-layer superlattice detectors (SLSs) and intraband quantum-dot infrared photodetectors (QDIPs).

In this work, we mainly explore two self-assembled quantum-dot (QD) materials for use as the absorber material in photon detectors for the LWIR, with the aim to develop low-dark current devices that can allow for high operating temperatures and high manufacturability. The detection mechanism is here based on type-II interband transitions from bound hole states in the QDs to continuum states in the matrix material.

Metal-organic vapor-phase epitaxy (MOVPE) was used to fabricate (Al)GaAs(Sb)/InAs and In(Ga)Sb/InAs QD structures for the development of an LWIR active material. A successive analysis of (Al)GaAs(Sb) QDs using absorption spectroscopy shows strong absorption in the range 6-12 µm interpreted to originate in intra-valence band transitions. Moreover, record-long photoluminescence (PL) wavelength up to 12 µm is demonstrated in InSb- and InGaSb QDs.

Mesa-etched single-pixel photodiodes were fabricated in which photoresponse is demonstrated up to 8 µm at 230 K with 10 In0.5Ga0.5Sb QD layers as the active region. The photoresponse is observed to be strongly temperature-dependent which is explained by hole trapping in the QDs. In the current design, the photoresponse is thermally limited at typical LWIR sensor operating temperatures (60-120 K), which is detrimental to the imaging performance. This can potentially be resolved by selecting a matrix material with a smaller barrier for thermionic emission of photo-excited holes. If such an arrangement can be achieved, type-II interband InGaSb QD structures can turn out to be interesting as a high-operating-temperature sensor material for thermal imaging applications.

Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2013. 81 p.
Series
Trita-ICT/MAP, 1653-7310Trita-ICT/MAP AVH, ISSN 1653-7610 ; 2013:03
Keyword
photodetector, quantum dot, infrared, MOVPE, thermal imaging, type-II, photoluminescence, III/V, InSb, InGaSb, InAs
National Category
Nano Technology
Research subject
SRA - ICT
Identifiers
urn:nbn:se:kth:diva-122294 (URN)978-91-7501-779-2 (ISBN)
Public defence
2013-06-14, Room D, Isafjordsgatan 39, Kista, 10:00 (English)
Opponent
Supervisors
Note

QC 20130521

Available from: 2013-05-21 Created: 2013-05-17 Last updated: 2013-05-21Bibliographically approved
2. Materials and Processing Technologies for Advanced Electronic and Photonic Devices
Open this publication in new window or tab >>Materials and Processing Technologies for Advanced Electronic and Photonic Devices
2014 (English)Doctoral thesis, comprehensive summary (Other academic)
Place, publisher, year, edition, pages
stockholm: KTH Royal Institute of Technology, 2014. 84 p.
Series
TRITA-ICT/MAP AVH, ISSN 1653-7610 ; 2014:15
National Category
Engineering and Technology
Identifiers
urn:nbn:se:kth:diva-157138 (URN)978-91-7595-351-9 (ISBN)
Public defence
2014-12-17, Sal/Hal A, Electrum, KTH-ICT, Kista, 10:00 (English)
Opponent
Supervisors
Note

QC 20141208

Available from: 2014-12-08 Created: 2014-12-07 Last updated: 2014-12-08Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full textScopus

Authority records BETA

Hallén, AndersHammar, Mattias

Search in DiVA

By author/editor
Gustafsson, OscarBerggren, JesperEkenberg, UlfHallén, AndersHammar, MattiasZhang, A.
By organisation
Integrated Devices and CircuitsPhotonics (Closed 20120101)
In the same journal
Infrared physics & technology
Electrical Engineering, Electronic Engineering, Information Engineering

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 131 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf