Light-emitting metal-oxide-semiconductor devices and associated systems, devices, and methods
View Patent ↗Various embodiments of solid state transducer (“SST”) devices are disclosed. In several embodiments, a light emitter device includes a metal-oxide-semiconductor (MOS) capacitor, an active region operably coupled to the MOS capacitor, and a bulk semiconductor material operably coupled to the active region. The active region can include at least one quantum well configured to store first charge carriers under a first bias. The bulk semiconductor material is arranged to provide second charge carriers to the active region under the second bias such that the active region emits UV light.
1. A light emitter device, comprising:
a semiconductor structure including a first semiconductor material and a second semiconductor material, wherein the second semiconductor material includes an active region having a bandgap configured to emit light; and
an electrode operably coupled to the second semiconductor material, wherein the electrode includes a conductive contact and a dielectric material between the active region and the conductive contact, wherein the electrode is configured to—accumulate charge in the active region, and
draw a discharge current through the first semiconductor material to discharge at least a portion of the accumulated charge.
2. The light emitter of claim 1 wherein the first semiconductor material includes an N-type semiconductor material, and wherein the second semiconductor materially operably couples the first semiconductor material to the electrode without an intermediary P-type material.
3. The light emitter of claim 2 wherein the bandgap is configured to separate charge carriers by one or more energy levels in the ultraviolet spectrum.
4. The light emitter of claim 2 wherein the electrode and at least a portion of the second semiconductor material define a capacitor structure.
5. The light emitter of claim 1 wherein the active region includes at least one quantum well.
6. The light emitter of claim 1 , further comprising a spacer between the second semiconductor material and the electrode.
7. The light emitter of claim 1 wherein:
the conductive contact is a first conductive contact;
the light emitter further comprises a second conductive contact connected to the first semiconductor material; and
the dielectric material prevents current flow between the first and second contacts.
8. An ultraviolet (UV) light emitter device, comprising:
a metal-oxide-semiconductor (MOS) capacitor;
an active region operably coupled to the MOS capacitor, wherein the active region includes at least one quantum well configured to store first charge carriers under a first bias;
a spacer material between the MOS capacitor and the active region; and
a bulk semiconductor material operably coupled to the active region, wherein the bulk semiconductor material is configured to provide second charge carriers to the active region such that the active region emits UV light.
9. The UV light emitter of claim 8 wherein:
the active region includes at least one of gallium nitride (GaN) or aluminum GaN (AlGaN); and
the bulk semiconductor material includes N-type AlGaN,
wherein the active region and the bulk semiconductor material do not include P-type GaN nor P-type AlGaN.
10. The UV light emitter of claim 8 wherein the spacer material includes at least one of gallium nitride (GaN) or aluminum GaN (AlGaN), but not P-type GaN nor P-type AlGaN.
11. The UV light emitter of claim 8 wherein:
the spacer material includes at least one of gallium nitride (GaN) or aluminum GaN;
the active region includes at least one of GaN or AlGaN; and
the bulk semiconductor material includes N-type AlGaN,
wherein the spacer material, the active region, and the bulk semiconductor material do not include P-type GaN nor P-type AlGaN.
12. The UV light emitter of claim 8 wherein the active region directly contacts the spacer.
13. A method for producing ultraviolet (UV) light, comprising:
biasing a metal-oxide (MOS) capacitor with at least a first voltage, wherein the MOS capacitor is operably coupled to an active region having energy bands configured for emitting UV light; and
biasing the MOS capacitor with at least a second voltage to emit the UV light from the active region.
14. The method of claim 13 wherein:
biasing the MOS capacitor with the first voltage further comprises applying the first voltage for a first duration of time to charge the MOS capacitor; and
biasing the MOS capacitor with the second voltage further comprises applying the second voltage for a second duration of time to discharge the MOS capacitor.
15. The method of claim 13 wherein biasing the MOS capacitor with the second voltage further comprises applying the second voltage for the second duration of time to partially discharge the MOS capacitor.
16. The method of claim 13 wherein biasing the MOS capacitor with the second voltage further comprises applying the second voltage for the second duration of time to completely discharge the MOS capacitor.
17. The method of claim 13 , further comprising generating a bias signal, wherein the bias signal includes the first voltage and the second voltage, and wherein the bias signal has a duty cycle configured to pulse the UV light.
18. The method of claim 13 , further comprising generating a bias signal, wherein the bias signal includes the first voltage and the second voltage, and wherein the bias signal has a duty cycle configured to output the UV light such that it is generally non-pulsed.