Optical concentration in fully delineated mid-wave infrared T2SL detectors arraysShow others and affiliations
2023 (English)In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 123, no 18, article id 181102Article in journal (Refereed) Published
Abstract [en]
The dependence of quantum efficiency (QE) on fill factor and pixel pitch is studied theoretically and experimentally in fully delineated type-II superlattice (T2SL) detectors. Theoretically, a 2-dimensional simulation model is used to compute the absorption in the array geometry, which shows an insensitivity of the optical response to the fill factor. This is a result of the photodiode array (PDA) geometry concentrating the light in the pixel area. QE measurements on PDAs with varying pixel pitch (from 225 to 10 μm) and fill factors (from 98% to 64%) confirm this independence of the QE on the fill factor and results in a 50% increase in the photocurrent density in 10 μm pitch PDAs compared to 225 μm pitch PDAs. Furthermore, measurements of the dark current density vs pixel size revealed an absence of surface leakage in these PDAs, which, combined with the increased photocurrent density results in an improved signal-to-noise ratio when reducing the pitch in these T2SL detectors. Finally, this result resolves the QE-modulation transfer function trade-off, as the electrical isolation of the pixel is carried out without impacting the QE of the array.
Place, publisher, year, edition, pages
AIP Publishing , 2023. Vol. 123, no 18, article id 181102
National Category
Telecommunications Atom and Molecular Physics and Optics
Identifiers
URN: urn:nbn:se:kth:diva-339717DOI: 10.1063/5.0176652ISI: 001094980200011Scopus ID: 2-s2.0-85175725964OAI: oai:DiVA.org:kth-339717DiVA, id: diva2:1813203
Note
QC 20231120
2023-11-202023-11-202024-02-21Bibliographically approved
In thesis