- #BAND GAP GROUND STATE VALENCE BAND CUT OFF WAVELENGTH SERIAL#
- #BAND GAP GROUND STATE VALENCE BAND CUT OFF WAVELENGTH FULL#
The contact layer and the detector structure are fully reticulated, and the common ground structure provides a common ground for the array of pixels.Ī method of fabricating a frontside-illuminated focal plane array includes providing a wafer having a bulk substrate layer, a contact layer disposed on the bulk substrate layer, a detector structure disposed on the contact layer, and a common ground structure disposed on the detector structure.
The common ground structure has a bandgap that is wider than a bandgap of the detector structure. The common ground structure is transmissive to radiation having a wavelength in a predetermined spectral band. The focal plane array further includes a common ground structure adjacent the detector structure and an optical layer adjacent the common ground structure. In another embodiment, a focal plane array includes an array of pixels, each pixel including an infrared detector device further including a contact layer and a detector structure adjacent to the contact layer, wherein the detector structure is capable of absorbing radiation. The front-side illuminated infrared detector device further includes an optical layer adjacent the common ground structure. The front-side illuminated infrared detector device further includes a common ground structure adjacent the detector structure, wherein the common ground structure is transmissive to radiation having a wavelength in a predetermined spectral band, and the common ground structure has a bandgap that is wider than a bandgap of the detector structure. The detector structure is capable of absorbing radiation. In one embodiment, a front-side illuminated infrared detector device includes a contact layer and a detector structure adjacent to the contact layer. These FPA architectures may be applied to device structures including, but not limited to, nBn, nBP, pBp, xBn, p-i-n, and pn junctions.
#BAND GAP GROUND STATE VALENCE BAND CUT OFF WAVELENGTH FULL#
In some embodiments, a common ground layer serves as an etch stop structure, thereby allowing full pixel reticulation with minimal erosion into the ground plane. SUMMARYĮmbodiments described herein are directed to wider bandgap contact designs that are transparent to the interested infrared bands, and serve as a focal plane array (FPA) common contact/ground at a same time. Further, the frontside contact layer may not provide enough electrical conductivity to serve as common grounding layer needed for FPA operations.Īccordingly, a need exists for alternative infrared detector device structures that improve quantum efficiency with sufficient grounding. However, in-band photon absorption in the contact layer may lead to certain systematic quantum efficiency loss. Such nBn devices can be used to improve the operating temperature of an infrared focal plane arrays (FPA).įor an nBn detector structure, illumination from the thin frontside contact has the advantage for maximizing the quantum efficiency due to proximity of photo generated carriers to the contact. The nBn device structure generally includes an n-type absorber layer, a barrier layer to block majority carriers, and an n-type contact layer. The nBn device structure has been used to improve the operating temperature of photoconductive infrared detectors by blocking the flow of electrons. The present specification generally relates to infrared detector devices and, more particularly, to infrared detector devices and focal plane arrays incorporating a transparent common ground structure. 1, 2017, the contents of which are incorporated by reference in their entirety. 25, 2017, which claims the benefit of U.S.
#BAND GAP GROUND STATE VALENCE BAND CUT OFF WAVELENGTH SERIAL#
This application is a continuation of PCT application serial no.