All inorganic perovskite materials for short wave IR devices

1. An inorganic perovskite material having a formula of A + B 2+ XY 2 wherein:

A + X is a first metal salt comprising: A + , a first monovalent alkali metal cation, and X, a first monovalent anion; and

B 2+ Y 2 is a second metal salt comprising: B 2+ , a second bivalent alkali earth metal, heavy metal, or transition metal cation, and Y 2 , two second monovalent anions;

wherein the inorganic perovskite material further comprises a stabilizer comprising 1-(3-sulfopropyl) pyridinium hydroxide inner salt, and

wherein a molar ratio of the first metal salt to the second metal salt is about 2:1.

2. The inorganic perovskite material of claim 1 , wherein the first metal salt is cesium iodide.

3. The inorganic perovskite material of claim 1 , wherein the second metal salt is lead (II) iodide.

4. The inorganic perovskite material of claim 1 , wherein the stabilizer is present at a weight ratio of about 0.8% compared to the combined weight of the first metal salt and the second metal salt.

5. The inorganic perovskite material of claim 1 , wherein the first monovalent anion and/or the two second monovalent anions are Br—, Cl—, I—, or combinations thereof.

6. The inorganic perovskite material of claim 1 , further comprising the inorganic perovskite material is a layer on a glass substrate; the glass substrate operative to stabilize the inorganic perovskite material.

7. The inorganic perovskite material of claim 6 , wherein the inorganic perovskite material does not change in maximum wavelength of absorbance from 1000 nm to 2800 nm at ambient temperature for longer than about 8 days.

8. The inorganic perovskite material of claim 1 , wherein the inorganic perovskite material has a highest SWIR absorbance between about 1000-2800 nm.

9. A method of making an inorganic perovskite material having a formula of A + B 2+ XY 2 , comprising:

preparing a precursor solution in a solvent by:

dissolving a first metal salt containing a first monovalent alkali metal cation, A + , and a first monovalent anion, X, in the solvent;

dissolving an second metal salt containing a second bivalent alkali earth metal, heavy metal, or transition metal cation, B 2+ , and two second monovalent anions, Y 2 , in the solvent,

wherein a molar ratio of the first metal salt to the second metal salt is about 2:1 in the solvent;

adding a stabilizer to the precursor solution;

dispersing the precursor solution on a substrate; and

annealing the dispersed precursor solution on the substrate at an annealing temperature from 40-300° C., to form an inorganic perovskite material,

wherein the stabilizer comprises 1-(3-sulfopropyl) pyridinium hydroxide inner salt.

10. The method of claim 9 , wherein annealing is done in a vacuum.

11. The method of claim 9 , wherein the preparing a precursor solution in a solvent is at a temperature from 60-80° C. and wherein dispersing the precursor solution on a substrate is at less than 110° C.

12. The method of claim 9 , wherein the first metal salt is cesium iodide and the second metal salt is lead (II) iodide.

13. The method of claim 12 , wherein the annealing temperature is about 50° C. and wherein the inorganic perovskite material is operative to have a maximum SWIR absorbance at about 1200 nm.

14. The method of claim 12 , wherein the annealing temperature is about 80° C. and wherein the inorganic perovskite material is operative to have a maximum SWIR absorbance at about 1400 nm.

15. The method of claim 12 , wherein the annealing temperature is about 100° C. and wherein the inorganic perovskite material is operative to have a maximum SWIR absorbance at about 1500 nm.

16. The method of claim 9 , further comprising wherein the annealing temperature is operative to determine the wavelength of maximum SWIR absorbance of the inorganic perovskite material.

17. The method of claim 9 , wherein the solvent is dimethylformamide.

18. The method of claim 9 , wherein dispersing the precursor solution on a substrate is done by spin coating the precursor solution on the substrate.

19. The method of claim 9 , wherein the substrate is glass and the glass is operative to stabilize the inorganic perovskite material at ambient temperature.