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 solid state transducer (SST) system, comprising:
a light emitter device including a capacitor, a conductive contact, and an active region between the capacitor and the conductive contact; and
a waveform generator having a first terminal operably coupled to the capacitor and a second terminal operably coupled to the conductive contact, wherein the waveform generator is configured to generate a bias signal that alternatingly charges and discharges the capacitor to emit electromagnetic radiation from the active region.
2. The SST system of claim 1 wherein the capacitor includes a metal-oxide-semiconductor (MOS) capacitor.
3. The SST system of claim 1 wherein the electromagnetic radiation is in the ultraviolet (UV) spectrum.
4. The SST system of claim 1 wherein the light emitter device further includes a spacer between the active region and the capacitor region without a semiconductor material between the spacer and the active region.
5. The SST system of claim 1 wherein the bias signal includes a first waveform configured to accumulate charge in the capacitor and a second waveform configured to draw a current that at least partially discharges the accumulated charge.
6. The SST system of claim 1 wherein the bias signal has a charge/discharge cycle based on a charge time and a discharge time of the capacitor, wherein a duty cycle of the charge time and the discharge time is configured such that the active region outputs the electromagnetic radiation throughout charge/discharge cycle.
7. The SST system of claim 1 wherein the bias signal has a charge/discharge cycle based on a charge time and a discharge time of the capacitor, wherein a duty cycle of the charge time and the discharge time is configured such that the active region does not emit the electromagnetic radiation for a portion of the charge/discharge cycle.
8. The SST system of claim 1 wherein the bias signal has a frequency configured such that the electromagnetic radiation is pulsed.
9. The SST system of claim 1 wherein the bias signal has a frequency configured such that the electromagnetic radiation is generally non-pulsed.
10. A method for operating a light emitter device having a capacitor, a conductive contract, and an active region between the capacitor and the conductive contact, the method comprising:
generating a bias signal using a waveform generator, the waveform generator having a first terminal operably coupled to the capacitor, and a second terminal operably coupled to the conductive contact, and
alternatively charging and discharging the capacitor with the bias signal generated by the waveform generator to emit electromagnetic radiation from the active region.
11. The method of claim 10 wherein charging the capacitor includes charging the capacitor with a bias signal, wherein a duty cycle of the bias signal is configured such that the capacitor emits a portion of the electromagnetic radiation while the capacitor is charging.
12. The method of claim 10 wherein a duty cycle of the bias signal is configured to pulse the electromagnetic radiation.
13. The method of claim 10 wherein the capacitor includes a metal-oxide-semiconductor (MOS) capacitor and the active region includes at least one quantum well operably coupled to the MOS capacitor to emit the electromagnetic radiation.
14. The method of claim 10 wherein the electromagnetic radiation is in the ultraviolet (UV) spectrum.
15. The method of claim 10 wherein alternatingly charging and discharging the capacitor with the bias signal includes alternatingly cycling the bias signal between at least a first voltage and at least a second voltage different than the first voltage.
16. The method of claim 10 wherein alternatingly charging and discharging the capacitor with the bias signal further includes:
applying the first voltage for a first duration of time to charge the capacitor; and
applying the second voltage for a second duration of time to discharge the capacitor.
17. The method of claim 16 wherein alternatingly charging and discharging the capacitor with the bias signal further includes applying the second voltage for a duration of time to discharge the capacitor.
18. A solid state transducer (SST) system, comprising:
a waveform generator having a first terminal and a second terminal, wherein the waveform generator is configured to apply a bias signal across the first and second terminals; and
a light emitter device having an active region, a conductive contact between active region and the first terminal, and a capacitor between the active region and the second terminal,
wherein the waveform generator is configured to alternatingly charge and discharge the capacitor via the applied biased signal to emit electromagnetic radiation from the active region.
19. The SST system of claim 18 wherein the capacitor comprises a metal-oxide-semiconductor (MOS) capacitor and the active region includes at least one quantum well.
20. The SST system of claim 18 , further comprising a bulk semiconductor material between the conductive contact and the capacitor.
21. The SST system of claim 20 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.
22. The SST system of claim 18 , further comprising a spacer material between the capacitor and the active region.
23. The SST system of claim 22 wherein the active region directly contacts the spacer.
24. The SST system of claim 18 , further comprising a bulk semiconductor material and a spacer, wherein the active region is between the bulk semiconductor material and the active region.
25. The SST system of claim 24 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.