Thin film emitter-absorber apparatus and methods
Methods and apparatus for providing a tunable absorption-emission band in a wavelength selective device are disclosed. A device for selectively absorbing incident electromagnetic radiation includes an electrically conductive surface layer including an arrangement of multiple surface elements. The surface layer is disposed at a nonzero height above a continuous electrically conductive layer. An electrically isolating intermediate layer defines a first surface that is in communication with the electrically conductive surface layer. The continuous electrically conductive backing layer is provided in communication with a second surface of the electrically isolating intermediate layer. When combined with an infrared source, the wavelength selective device emits infrared radiation in at least one narrow band determined by a resonance of the device. In some embodiments, the device includes a control feature that allows the resonance to be selectively modified. The device has broad applications including gas detection devices and infrared imaging.
1. A tunable optoelectronic device having at least one absorption resonance and/or at least one reflection resonance, the tunable optoelectronic device comprising:
two or more layers comprising a conductive layer and at least one of an insulating layer and a semiconducting layer;
a plurality of discrete surface features on at least one of the two or more layers, the plurality of discrete surface features arranged to establish the at least one absorption resonance and/or the at least one reflection resonance; and
a tuner configured to change at least one controllable property of at least one of the two or more layers, wherein a resonance property of the at least one absorption resonance and/or the at least one reflection resonance depends on the at least one controllable property changed by said tuner.
2. The tunable optoelectronic device of claim 1 , wherein the resonance property comprises one or more properties selected from the group consisting of wavelength, bandwidth, intensity, and number of resonances.
3. The tunable optoelectronic device of claim 1 , wherein the tuner is configured to change at least one controllable property of at least one of the two or more layers with a speed ranging between one hertz and one megahertz.
4. The tunable optoelectronic device of claim 1 , wherein the layers are configured to form at least one electrical component selected from the group consisting of a thin film resistor, a thin film transistor and a field effect transistor, wherein the tuner is configured to change at least one controllable property of at least one of the two or more layers by applying voltage or electrical current.
5. The tunable optoelectronic device of claim 1 , wherein the at least one controllable property of the at least one of the two or more layers is the conductivity of at least one of the two or more layers.
6. The tunable optoelectronic device of claim 5 , wherein the tuner is configured to change the conductivity of at least one of the two or more layers by changing the temperature of at least one of the two or more layers.
7. The tunable optoelectronic device of claim 6 , wherein the tuner is configured to change the temperature of at least one of the two or more layers using Joule heating.
8. The tunable optoelectronic device of claim 5 , wherein:
the two or more layers comprises a photovoltaic layer; and
the tuner is configured to change the conductivity of the photovoltaic layer by illuminating the photovoltaic layer with light energy.
9. The tunable optoelectronic device of claim 1 , wherein the at least one absorption resonance and/or the at least one reflection resonance comprises at least two resonances.
10. The tunable optoelectronic device of claim 9 , wherein the tuner is configured to independently control each of the at least two resonances.
11. A tunable optoelectronic device comprising:
a plurality of pixels, each pixel having at least one absorption resonance and/or at least one reflection resonance, and each pixel comprising:
two or more layers comprising an insulating or semiconducting layer and a conductive layer; and
a plurality of discrete surface features on at least one of the two or more layers, the plurality of discrete surface features arranged to establish the at least one absorption resonance and/or the at least one reflection resonance; and
a tuner configured to change at least one controllable property of at least one of the two or more layers of each of the pixels independently, wherein a resonance property of the at least one absorption resonance and/or the at least one reflection resonance of each pixel depends on the at least one controllable property changed by said tuner.
12. The tunable optoelectronic device of claim 11 , wherein the resonance property of each pixel comprises one or more properties selected from the group consisting of wavelength, bandwidth, intensity and number of resonances.
13. The tunable optoelectronic device of claim 11 , wherein the tuner is configured to change the at least one controllable property of at least one of the two or more layers of each of the pixels independently from the other pixels of the plurality of pixels.
14. The tunable optoelectronic device of claim 11 where the layers of each pixel are configured to form at least one electrical component selected from the group consisting of a thin film resistor, a thin film transistor and a field effect transistor, wherein the tuner is configured to change at least one controllable property of at least one of the two or more layers of each of the pixels by applying voltage or electrical current.
15. The tunable optoelectronic device of claim 11 , wherein the at least one controllable property of at least one of the two or more layers of each of the pixels is the conductivity of at least one of the two or more layers of each of the pixels.
16. The tunable optoelectronic device of claim 15 , wherein the tuner is configured to change the conductivity of at least one of the two or more layers of each of the pixels by changing the temperature of at least one of the two or more layers.
17. The tunable optoelectronic device of claim 16 , wherein the tuner is configured to change the temperature of at least one of the two or more layers of each of the pixels using Joule heating.
18. The tunable optoelectronic device of claim 15 , wherein:
the two or more layers of each of the pixels comprises a photovoltaic layer; and
the tuner is configured to change the conductivity of the photovoltaic layer by illuminating the photovoltaic layer of each of the pixels with light energy.
19. The tunable optoelectronic device of claim 11 , wherein the at least one absorption resonance and/or the at least one reflection resonance comprises at least two resonances, and the tuner is configured to independently control each of the at least two resonances.
20. The tunable optoelectronic device of claim 11 , wherein tunable optoelectronic device is a display device or an imaging device.