Composite quantum-dot materials for photonics detectors
A method of manufacturing a composite quantum-dot photodetector formed by alternatively dipping a substrate into a colloidal solution containing at least one type of a quantum dot, thereby forming a monolayer of the quantum dots and then dipping the substrate with the monolayer of the quantum dots into a ligand spacing solution to build a film of the quantum dots and then alternatively exposing the film of the quantum dots to a vapor and an infill material.
1. A method of manufacturing a composite quantum-dot photodetector film, the method comprising:
alternatively dipping a substrate into a colloidal solution containing at least one type of a quantum-dot, thereby forming a monolayer of the quantum dots and then dipping the substrate with the monolayer of the quantum dots in a ligand spacing solution to build a lattice of the quantum dots; and
alternatively exposing the lattice of the quantum dots to a vapor and an infill material, wherein exposing the film to the vapor coats the lattice's accessible surfaces providing oxygen to the infill material for reaction and then exposing the lattice to the infill material penetrating pores of the film and reacting with the film's accessible surfaces to form an inorganic matrix isolating the quantum dots from atmospheric exposure.
2. The method of claim 1 wherein the monolayer is made from the quantum-dot type InSb, InGaP, PbS, PbSe, PbTe, PbI 2 , HgS, HgTe, LaF 3 , CdS, CuInS 2 , CuZnInS 2 , CdSe, HfO 2 , CIS, CZTS, YV(B)O 4 , ZnS, ZrO 2 or combinations thereof.
3. The method of claim 1 wherein the substrate is a CMOS wafer, containing electrical circuits for biasing or amplifying the signal from the photodetector.
4. The method of claim 1 wherein the photodetector is a pixelated array.
5. The method of claim 1 wherein the photodetector film is doped p-type.
6. The method of claim 1 wherein the photodetector film is doped p-type.
7. The method of claim 1 wherein the quantum-dot is an alloy, containing more than two atomic elements.
8. The method of claim 1 wherein the process is repeated using a different quantum-dot type, inorganic matrix material, or combinations thereof to form a heterojunction within the photodetector film.
9. The method of claim 8 , wherein the quantum-dots form a heterostructure within the organic matrix.
10. The method of claim 8 , wherein the quantum-dot forms a type-II heterostructure with the infill semiconductor material.
11. The method of claim 8 , wherein the quantum-dot is doped p-type.
12. The method of claim 8 , wherein the quantum-dot is doped n-type.
13. The method of claim 1 , wherein infill material forms a potential barrier to both the holes and electrons in the quantum-dots.
14. The method of claim 1 , wherein the infill material is chosen to promote extraction of one, but not both charge carriers.
15. The method of claim 1 , wherein the infilled quantum-dots and infill material is chosen to create a p+/n, p-i-n, or n-B-n photodetector.
16. The method of claim above, further comprising the step of depositing a transparent conductive material.
17. The method of claim 1 , wherein the infill material type is a sulfide, oxide, halide.
18. The method of claim 1 , wherein the inorganic matrix comprises of Al 2 O 3 , ZrO 2 , HfO 2 , or combinations thereof.
19. The method of claim 1 wherein the solution of spacing ligand is 1,2 ethylene dithiol.
20. The method of claim 1 , wherein doping techniques are used to modify the photodetector film properties.