Claims
- 1. In a multilayer thin-film device having adjacent insulator and semiconductor layers and producing an increased luminescence efficiency, the improvement which comprises:
- means to maintain a charge near the insulator-semiconductor interface of proper polarity and sufficient magnitude to create a depletion region in said semiconductor layer that substantially reduces majority carrier tunneling from the conduction band of said semiconductor layer and enhances minority carrier injection into said semiconductor layer and the resulting luminescence.
- 2. A device according to claim 1, wherein said means to maintain a charge includes means for introducing a surface state at said insulator-semiconductor interface which produces said depletion region.
- 3. A device according to claim 1 wherein said multilayer thin-film device is of the semiconductor-insulator-semiconductor (SIS) type.
- 4. A device according to claim 1 wherein said means to maintain a charge near the insulator-semiconductor interface includes a semiconductor surface adjacent to said insulator which is substantially free of oxides and contaminants.
- 5. A device according to claim 4 wherein said semiconductor surface which is substantially free of oxides and contaminants is produced by cleaning in the presence of high vacuum.
- 6. A device according to claim 5 wherein said cleaning employs sputter-etching or ion-milling.
- 7. A multilayer thin-film device for producing electroluminescence, comprising:
- a first layer of semiconductor material;
- means forming a depletion region at a first surface of said semiconductor layer;
- a second, thin-film layer of insulator material deposited on said first surface of said semiconductor layer;
- a third layer of metal material deposited on said insulator material;
- means for applying a bias voltage across said device, said bias voltage and said depletion region cooperating to produce band-bending in the energy band gap of said semiconductor adjacent the interface between said first and second layers to substantially reduce majority carrier tunneling from the conduction band of said first layer to said third layer, and to lower the voltage threshold for minority carrier tunneling into said first layer from said third layer to less than the band gap of said semiconductor material of said first layer whereby minority carrier tunneling is enhanced to produce improved electroluminescence.
- 8. The device of claim 7, wherein said first layer is GaAs, said second layer is Al.sub.2 O.sub.3, and said third layer is Al.
Government Interests
The invention herein described was made in the course of or under a contract or subcontract thereunder with the Office of Naval Research.
US Referenced Citations (5)