Article Dans Une Revue Opto-Electronics Review Année : 2023

Discussion around IR material and structure issues to go toward high performance small pixel pitch IR HOT FPAs

Résumé

In the last decade, infrared imaging detectors trend has gone for smaller pixels and larger formats. Most of the time, this scaling is carried out at a given total sensitive area for a single focal plane array. As an example, QVGA 30 µm pitch and VGA 15 µm pitch exhibit exactly the same sensitive area. SXGA 10 µm pitch tends to be very similar, as well. This increase in format is beneficial to image resolution. However, this scaling to even smaller pixels raises questions because the pixel size becomes similar to the IR wavelength, but also to the typical transport dimensions in the absorbing material. Hence, maintaining resolution for such small pixel pitches requires a good control of the modulation transfer function and quantum efficiency of the array, while reducing the pixel size. This might not be obtained just by scaling the pixel dimensions. As an example, bulk planar structures suffer from excessive lateral diffusion length inducing pixel-to-pixel cross talk and thus degrading the modulation transfer function. Transport anisotropy in some type II superlattice structures might also be an issue for the diffusion modulation transfer function. On the other side, mesa structures might minimize cross talk by physically separating pixels, but also tend to degrade the quantum efficiency due to a non-negligible pixel fill factor shrinking down the pixel size. This paper discusses those issues, taking into account different material systems and structures, in the perspective of the expected future pixel pitch infrared focal plane arrays.
Fichier principal
Vignette du fichier
Gravrand et al. - 2023 - Opto-Electronics Review - Discussion around IR material and structure issues to go toward small pixel pitch IR.pdf (1.96 Mo) Télécharger le fichier
Origine Fichiers éditeurs autorisés sur une archive ouverte

Dates et versions

cea-04575269 , version 1 (14-05-2024)

Identifiants

Citer

Olivier Gravrand, Nicolas Baier, Alexandre Ferron, Florent Rochette, Clément Lobre, et al.. Discussion around IR material and structure issues to go toward high performance small pixel pitch IR HOT FPAs. Opto-Electronics Review, 2023, 31, pp.e144561. ⟨10.24425/opelre.2023.144561⟩. ⟨cea-04575269⟩
25 Consultations
13 Téléchargements

Altmetric

Partager

More