Optical ovonic threshold switch
View Patent ↗A method and device for accomplishing transformation of a switching material from a resistive state to a conductive state. The method utilizes a non-electrical source of energy to effect the switching transformation. The switching material may be a chalcogenide switching material, where the non-electrical source of energy initiates switching by liberating lone pair electrons from bound states of chalcogen atoms. The liberated lone pair electrons form a conductive filament having the characteristics of a solid state plasma to permit high current densities to pass through the switching material. The device includes a switching material with electrical contacts and may be interconnected with other elements in a circuit to regulate electrical communication therebetween.
1. A method of operating a switching material comprising:
providing a switching material, said switching material having a resistive state, a conductive state and a structural phase, said switching material comprising four or more elements;
providing non-electrical energy to said switching material, said non-electrical energy inducing a transformation of said switching material from said resistive state to said conductive state, said non-electrical energy not altering said structural phase during said transformation.
2. The method of claim 1 , wherein said switching material is a threshold switching material.
3. The method of claim 1 , wherein said switching material comprises a chalcogenide material.
4. The method of claim 3 , wherein said chalcogenide material comprises Te or Se.
5. The method of claim 4 , wherein the atomic concentration of said Te or Se is at least 30%.
6. The method of claim 5 , wherein the atomic concentration of said Te or Se is at least 50%.
7. The method of claim 4 , wherein said chalcogenide material further comprises Ge or In.
8. The method of claim 7 , wherein said chalcogenide material further comprises Si, Sb or As.
9. The method of claim 1 , wherein said structural phase is an amorphous phase.
10. The method of claim 1 , wherein said non-electrical energy is electromagnetic energy.
11. The method of claim 10 , wherein said electromagnetic energy has a wavelength between 100 μm and 1 μm.
12. The method of claim 10 , wherein said electromagnetic energy has a wavelength of less than 1 μm.
13. The method of claim 1 , wherein said transformation comprises forming a conductive filament within said switching material, said switching material including a first portion and a second portion, said conductive filament occupying said first portion, said switching material being in said resistive state in said second portion.
14. The method of claim 13 , wherein said conductive filament comprises unbound electrons, said unbound electrons being removed from bound orbital states by said non-electrical energy.
15. The method of claim 14 , wherein said bound orbital states are lone pair states.