Title

Uncooled Mwir Sic Optical Detector Response Dynamics And Digital Imaging

Keywords

mid-wave infrared; optical detector; response dynamics; Silicon carbide; uncooled detector; wide bandgap

Abstract

Crystalline silicon carbide (SiC) is a wide bandgap covalent semiconductor material with excellent thermo-mechanical and optical properties. While the covalent bonding between the Si and C atoms allows n-type or p-type doping by incorporating dopant atoms into both the Si and C sites, the wide bandgap enables fabrication of optical detectors over a wide range of wavelengths. To fabricate a mid-wave infrared (MWIR) detector, an n-type 4H-SiC substrate is doped with Ga using a laser doping technique. The Ga atoms produce an acceptor level of 0.30 eV which corresponds to the MWIR wavelength of 4.21 μm. Photons of this wavelength excite electrons from the valence band to the acceptor level, thereby modifying the electron density, refractive index, and reflectance of the substrate. This change in reflectance constitutes the detector response. The dynamics of the detector response are studied by placing a chopper at a constant angular velocity between the MWIR radiation source and the detector. The imaging capability of the detector is established by reflecting incoherent light at a wavelength of 633 nm, which is produced by projecting illumination from a light-emitting diode (LED) off the detector towards a CMOS camera and examining the digital output of the camera to determine the relative intensity of the incident radiation. In addition, a mathematical model is presented to analyze the dynamic response and determine the electron density and lifetime in the acceptor level. © 2012 SPIE.

Publication Date

12-1-2012

Publication Title

Proceedings of SPIE - The International Society for Optical Engineering

Volume

8540

Number of Pages

-

Document Type

Article; Proceedings Paper

Personal Identifier

scopus

DOI Link

https://doi.org/10.1117/12.2009521

Socpus ID

84886780655 (Scopus)

Source API URL

https://api.elsevier.com/content/abstract/scopus_id/84886780655

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