Simultaneous dual-band systems and methods
The present disclosure is directed generally to simultaneous dual-band systems and methods. A dual-band system as disclosed herein includes a plurality of pixels. Each pixel comprising a first absorber layer; a first intervening layer located adjacent the first absorber layer; a second absorber layer located adjacent to the first intervening layer; and a second intervening layer located adjacent to the second absorber layer. The plurality of pixels includes a first subset of pixels for detecting light in a first band and a second subset of pixels for detecting light in a second band. Carriers created in the first absorber layer of the first subset of pixels are collected via the first contact layer. Carriers created in the second absorber layer of the second subset of pixels are collected via the second contact layer and carriers created in the first absorber layer remain uncollected.
1 . A dual-band imaging device comprising:
a plurality of pixels, wherein each of the plurality of pixels comprises:
a first absorber layer;
a first intervening layer located adjacent the first absorber layer;
a second absorber layer located adjacent to the first intervening layer; and
a second intervening layer located adjacent to the second absorber layer;
wherein the plurality of pixels includes a first subset of pixels for detecting light in a first band and a second subset of pixels for detecting light in a second band,
the first subset of pixels comprising:
a first ground plane contact in contact with the first absorber layer; and
a first contact layer in contact with the second absorber layer,
wherein carriers created in the first absorber layer are collected via the first contact layer;
the second subset of pixels comprising:
a second ground plane contact in contact with the second absorber layer; and
a second contact layer in contact with the second intervening layer,
wherein carriers created in the second absorber layer are collected via the second contact layer and
wherein carriers created in the first absorber layer remain uncollected.
2 . The dual-band imaging device of claim 1 , wherein:
the first absorber layer is an n-type semiconductor,
the first intervening layer is a p-type semiconductor,
the second absorber layer is an n-type semiconductor, and
the second intervening layer is a p-type semiconductor,
wherein the first subset of pixels includes an n-p-n detector that includes the first absorber layer, the first intervening layer, and the second absorber layer, and
wherein the second subset of pixels includes p-n detector that includes the second absorber layer and the second intervening layer.
3 . The dual-band imaging device of claim 1 , wherein:
the first absorber layer is a p-type semiconductor,
the first intervening layer is an n-type semiconductor,
the second absorber layer is a p-type semiconductor, and
the second intervening layer is an n-type semiconductor,
wherein the first subset of pixels includes an p-n-p detector that includes the first absorber layer, the first intervening layer, and the second absorber layer, and
wherein the second subset of pixels includes n-p detector that includes the second absorber layer and the second intervening layer.
4 . The dual-band imaging device of claim 1 , wherein:
the first absorber layer is an n-type semiconductor,
the first intervening layer is a barrier layer,
the second absorber layer is an n-type semiconductor, and
the second intervening layer comprises a barrier layer and a p-type semiconductor layer formed adjacent to the barrier layer,
wherein the first subset of pixels includes an n-b-n detector that includes the first absorber layer, the first intervening layer, and the second absorber layer, and
wherein the second subset of pixels includes pb-n detector that includes the second absorber layer and the second intervening layer.
5 . The dual-band imaging device of claim 1 , wherein:
the first absorber layer is a p-type semiconductor,
the first intervening layer is a barrier layer,
the second absorber layer is a p-type semiconductor, and
the second intervening layer comprises a barrier layer and an n-type semiconductor layer,
wherein the first subset of pixels includes an p-b-p detector that includes the first absorber layer, the first intervening layer, and the second absorber layer, and
wherein the second subset of pixels includes an nb-p detector that includes the second absorber layer and the second intervening layer.
6 . The dual-band imaging device of claim 1 , wherein a deep mesa etch separates the first subset of pixels from the second subset of pixels, wherein the deep mesa etch extends through the second intervening layer, the second absorber layer, the first intervening layer, and at least partially through the first absorber layer.
7 . A dual-band imaging device comprising:
a first pixel comprised of:
a first absorber layer,
a second absorber layer,
a first intervening layer located between the first and second absorber layers,
a second intervening layer located on top of the second absorber layer,
a first ground contact in electrical contact with the first absorber layer, and
a first upper contact in electrical contact with the second absorber layer,
wherein the first pixel collects carriers created in the first absorber layer using a first diode detector comprising the first absorber layer, the first intervening layer, and the second absorber layer; and
a second pixel comprised of:
the first absorber layer,
the second absorber layer,
the first intervening layer located between the first and second absorber layers,
the second intervening layer located on top of the second absorber layer,
a second ground contact in electrical contact with the second absorber layer, and
a second upper contact in electrical contact with the second intervening layer,
wherein the second pixel collects carriers created in the second absorber layer using a second diode detector comprising the second absorber layer and the second intervening layer.
8 . The dual-band imaging device of claim 7 , wherein a first trench is formed around the first pixel, wherein the first trench extends through the first and second intervening layers, the second absorber layer, and at least a portion of the first absorber layer.
9 . The dual-band imaging device of claim 8 , wherein a second trench is formed around the second pixel, wherein the second trench extends through the second intervening layer and at least a portion of the second absorber layer.
10 . The dual-band imaging device of claim 7 , wherein the dual-band image device includes a first plurality of first pixels and a second plurality of second pixels.
11 . The dual-band imaging device of claim 10 , wherein the second plurality of pixels are greater in number than the first plurality of pixels.
12 . The dual-band imaging device of claim 7 , wherein the first diode detector is a N-P-N detector, wherein the first absorber layer is an n-type semiconductor layer, the first intervening layer is a p-type semiconductor layer, and the second absorber layer is an n-type semiconductor layer.
13 . The dual-band imaging device of claim 12 , wherein the second diode detector is a P-N detector, wherein the second intervening layer is a p-type semiconductor layer.
14 . The dual-band imaging device of claim 7 , wherein the first diode detector is a P-N-P detector, wherein the first absorber layer is an p-type semiconductor layer, the first intervening layer is an n-type semiconductor layer, and the second absorber layer is a p-type semiconductor layer.
15 . The dual-band imaging device of claim 14 , wherein the second diode detector is a N-P detector, wherein the second intervening layer is an n-type semiconductor layer.
16 . The dual-band imaging device of claim 7 , wherein the first diode detector is a N-B-N detector, wherein the first absorber layer is an n-type semiconductor layer, the first intervening layer is a barrier layer, and the second absorber layer is an n-type semiconductor layer.
17 . The dual-band imaging device of claim 16 , wherein the second diode detector is an PB-N detector, wherein the second intervening layer includes a barrier layer and a p-type semiconductor layer stacked on top of the barrier layer.
18 . The dual-band imaging device of claim 7 , wherein the first diode detector is a P-B-P detector, wherein the first absorber layer is an p-type semiconductor layer, the first intervening layer is a barrier layer, and the second absorber layer is an p-type semiconductor layer.
19 . The dual-band imaging device of claim 18 , wherein the second diode detector is a NB-P detector, wherein the second intervening layer includes a barrier layer and a n-type semiconductor layer stacked on top of the barrier layer.
20 . The dual-band imaging device of claim 7 , further including:
a read-out integrated circuit (ROIC) comprising a plurality of electrical bumps, each bump in contact with one of the first upper contacts or second upper contacts,
wherein the ROIC is a single polarity device that provides a single bias voltage to each of the plurality of electrical bumps.