Method for Solvent Free Perovskite Deposition

1 . A method for solvent-free perovskite deposition, comprising:

loading a lead powder sample into a crucible;

placing a substrate face-down over the powder in the crucible;

reducing the pressure in the deposition chamber to 200 mTorr;

sublimating the lead powder sample;

making a first deposition on the substrate.

2 . The method of claim 1 , wherein:

the lead powder sample comprises lead (II) iodide;

the method further comprising backfilling the deposition chamber with the vapors of a salt precursor prior to making the first deposit, the salt precursor comprising a salt selected from the group consisting of formamidinium iodide, methyl ammonium iodide, and combinations thereof; and

wherein the first deposition is a perovskite material.

3 . The method of claim 2 , wherein the first 20 nm of depositions are made at a rate of 0.5 Å/second.

4 . The method of claim 1 , further comprising:

after making the first deposition, backfilling the deposition chamber with hydrogen iodide vapor and one or both of formamidine or methylamine;

making a second deposition on the substrate, the second deposition a perovskite material.

5 . The method of claim 1 , wherein:

the lead powder sample comprises lead (II) iodide; and

the method further comprising:

replacing leftover lead powder sample in the crucible with a salt precursor powder, the salt precursor comprising a salt selected from the group consisting of formamidinium iodide, methyl ammonium iodide, and combinations thereof;

sublimating the salt precursor;

making a second deposition on the substrate, the second deposition a perovskite material.

6 . The method of claim 5 , wherein the first 20 nm of depositions are made at a rate of 0.5 Å/second.

7 . The method of claim 2 , wherein backfilling occurs at a rate in the range of 2-100 sccm.

8 . The method of claim 1 , wherein the lead powder sample is a single crystal perovskite with the structure ABX 3 .

9 . A method for solvent-free perovskite deposition, comprising:

loading a lead salt precursor into a crucible;

loading a substrate into a sample holder;

reducing the pressure in the deposition chamber to at least 10 −3 Torr;

applying a current to ionize the lead salt precursor;

backfilling the deposition chamber with the vapors of a second salt precursor; and

depositing a perovskite material on the substrate.

10 . The method of claim 9 , wherein:

the lead salt precursor comprises lead (II) iodide;

the second salt precursor comprises hydrogen iodide; and

the method further comprises backfilling the deposition chamber with the vapors of a salt selected from the group consisting of formamidinium iodide, methyl ammonium iodide, and combinations thereof.

11 . The method of claim 9 , wherein:

the lead salt precursor is ionized in the presence of a reactive gas;

the second salt precursor comprises a salt precursor selected from the group consisting of formamidinium iodide, methyl ammonium iodide, and combinations thereof.

12 . The method of claim 11 , wherein the reactive gas is selected from the group consisting of water, oxygen, nitrous oxide, ammonia, and nitrogen.

13 . The method of claim 9 , wherein the lead salt precursor comprises a salt selected from the group consisting of lead alkoxides, lead alkylamides, lead alkylsulfides, lead alkylselenides, plumbanes, and plumbylenes.

14 . The method of claim 9 , wherein the first 20 nm of depositions are made at a rate of 0.5 Å/second.

15 . The method of claim 9 , wherein the lead salt precursor comprises a salt selected from the group consisting of bis(1-dimethylaminio-2-methyl-2-propanolate)lead (II) (Pb(DMAMP) 2 ); bis(2,2,6,6-tetramethyl-3,5,heptanedionato)lead(II) (Pb(THD) 2 ); lead(II) hexafluoroacetylacetonate; plumbocene (PbCp 2 ); tetraethyllead(IV); bis[bis(trimethylsilyl)amido]lead(II); and rac-N 2 ,N 3 -di-tert-butane-2,3-diamido lead (II).

16 . A method for solvent-free perovskite deposition, comprising:

loading a lead salt precursor into a crucible;

loading a substrate in a sample holder;

reducing the pressure in the deposition chamber to between 5 Torr and 760 torr;

vaporizing the lead salt precursor;

performing metalorganic vapor phase epitaxy on the vapor;

backfilling the deposition chamber with the vapors of a second salt precursor; and

depositing, under an inert gas, a perovskite material on the substrate.

17 . The method of claim 16 , wherein the second salt precursor comprises a salt selected from the group consisting of formamidinium iodide, methyl ammonium iodide, and combinations thereof.

18 . The method of claim 15 , wherein:

the second salt precursor comprises hydrogen iodide; and

the method further comprises backfilling the deposition chamber with hydrogen iodide vapor.

19 . The method of claim 16 , vaporizing occurs by applying one of heat or a flow of electrons to the lead salt precursor.

20 . The method of claim 16 , wherein the lead salt precursor comprises a salt selected from the group consisting of lead alkoxides, lead alkylamides, lead alkylsulfides, lead alkylselenides, plumbanes, and plumbylenes.