Highly tunable colloidal perovskite nanoplatelets
Colloidal perovskite nanoplatelets can provide a material platform, with tunability extending from the deep UV, across the visible, into the near-IR. The high degree of spectral tunability can be achieved through variation of the cation, metal, and halide composition as well as nanoplatelet thickness.
1. A composition comprising:
one or more of a colloidal nanoplatelet of the formula (I):
L 2 [ABX 3 ] n-1 BX 4 (I)
wherein L is an organic ligand or combination thereof, A is a monovalent metal or organic molecular cation, B is a divalent metal cation, X includes a halide or combinations thereof, and n−1 is the number of unit cells in thickness, wherein n is 1, 2, 3 or 4, wherein L is a mixture of two different organic ligands or X is a mixture of two different halide ions when A is methylammonium and B is Pb.
2. The composition of claim 1 , wherein the organic ligand includes octylammonium (OA) or butylammonium (BA).
3. The composition of claim 1 , wherein the monovalent metal or organic molecular cation includes cesium (Cs), methylammonium (MA) or formamidinium (FA).
4. The composition of claim 1 , wherein the divalent metal cation is lead (Pb) or tin (Sn).
5. The composition of claim 1 , wherein the halide anion is chloride (Cl), bromide (Br), iodide (I), or combinations thereof.
6. The composition of claim 1 , wherein the n is 1 or 2.
7. The composition of claim 1 , wherein a peak absorption wavelength of the composition is between near-IR and UV.
8. A light-emitting diode comprising the composition of claim 1 .
9. A solar cell comprising the composition of claim 1 .
10. A method of modulating an absorption and emission spectrum of a composition comprising:
selecting a peak absorption wavelength between near-IR and UV;
synthesizing a mixture of one or more colloidal nanoplatelets of the formula (I):
L 2 [ABX 3 ] n-1 BX 4 (I)
wherein L is an organic ligand or combinations thereof, A is a monovalent metal or organic molecular cation, B is a divalent metal cation, X is a halide anion, and n−1 is the number of unit cells in thickness, wherein n is 1, 2, 3 or 4 and wherein the halide anion is chloride (Cl), bromide (Br), iodide (I), or combinations thereof, wherein L is a mixture of two different organic ligands or X is a mixture of two different halide ions when A is methylammonium and B is Pb; and
wherein the mixture has the selected peak absorption wavelength.
11. The method of claim 10 , wherein the organic ligand includes octylammonium (OA) or butylammonium (BA).
12. The method of claim 10 , wherein the monovalent metal or organic molecular cation includes cesium (Cs), methylammonium (MA) or formamidinium (FA).
13. The method of claim 10 , wherein the divalent metal cation is lead (Pb) or tin (Sn).
14. The method of claim 10 , wherein then is 1 or 2.