METHODS FOR PURIFYING PEROVSKITE PRECURSORS AND IMPROVED PEROVSKITES MANUFACTURED THEREFROM

1 . A method comprising:

preparing a mixture by dissolving at least two halide perovskite precursors in a first liquid;

forming a halide perovskite crystal in the mixture by lowering a solubility limit of at least one of the halide perovskite precursors; and

separating the halide perovskite crystal from the mixture, wherein:

at least one of the halide perovskite precursors contains an impurity, and

the halide perovskite crystal is substantially free of the impurity.

2 . The method of claim 1 , wherein the halide perovskite crystal comprises at least one of a 3D crystal, a 2D crystal, or a 1D crystal.

3 . The method of claim 2 , wherein:

the halide perovskite crystal has a chemical formula comprising at least one of ABX 3 or A 2 BX 4 ,

A is a monovalent cation, B is a divalent metal cation, and X is a monovalent halide anion, and

together, the at least two precursors comprise A, B, and X.

4 . The method of claim 3 , wherein:

the perovskite crystal comprises Cs z (FA x MA 1-x ) 1-z Pb(Cl w (I y Br 1-y ) 1-w ) 3 ,

0≤w≤1, 0≤x≤1, 0≤y≤1, and 0≤z≤1.

5 . The method of claim 3 , wherein the halide perovskite crystal comprises at least one of MAPbI 3 , MAFACsPbIBr, FAPbI 3 , FAPbBr 3 , MAPbBr 3 , CsPbBr 3 , CsPbI 3 , (CH 6 N)PbI 3 , or (C 4 H 12 N) 2 PbBr 4 .

6 . The method of claim 3 , wherein the halide perovskite precursors comprise BX 2 and AX.

7 . The method of claim 6 , wherein BX 2 has a purity between about 95% and about 99.99% on a trace metals basis.

8 . The method of claim 1 , wherein the impurity comprises a metal.

9 . The method of claim 8 , wherein the metal comprises at least one of Na, Mg, Al, Si, K, Ca, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ag, Ba, Bi, Rh, Pt, or Pd.

10 . The method of claim 1 , wherein the first liquid comprises at least one of a polar solvent or an ionic liquid.

11 . The method of claim 1 , wherein the forming further includes providing an additive to the mixture.

12 . The method of claim 1 , wherein the preparing is performed with the mixture at a first temperature between about 20° C. and about 180° C.

13 . The method of claim 12 , wherein the forming is performed with the mixture at a second temperature that is different than the first temperature.

14 . The method of claim 1 , wherein the forming comprises at least one of evaporating at least a portion of the mixture, applying ultrasound to the mixture, applying a mechanical treatment to the mixture, an acoustical treatment of the mixture, a pressure treatment of the mixture, an electrical treatment of the mixture, or an electromagnetic treatment of the mixture.

15 . The method of claim 1 , wherein, after the forming, the mixture comprises the halide perovskite crystal and a liquid phase comprising the impurity.

16 . The method of claim 15 , wherein:

the separating results in the separation of the mixture into the halide perovskite crystal as a solid stream and an effluent stream, and

the effluent stream comprises the liquid phase and the impurity.

17 . The method of claim 1 , further comprising after the separating, a removing from the halide perovskite crystal any remaining portion of the impurity.

18 . The method of claim 1 , further comprising:

after the separating, forming a halide perovskite film, wherein the forming utilizes the halide perovskite crystal as a precursor, and

the perovskite film has substantially the same composition of A, B, and X as the halide perovskite crystal precursor.

19 . A composition comprising:

a halide perovskite comprising at least one of ABX 3 or A 2 BX 4 , wherein:

A is a monovalent cation, B is a divalent metal cation, and X is a monovalent halide anion, and

the halide perovskite further comprises N-methylformamidinium.

20 . The composition of claim 19 , wherein the film further comprises methylammonium at a concentration between 0 wt % and 1 wt %.