Optoelectronic devices with organometal perovskites with mixed anions
The invention provides an optoelectronic device comprising a mixed-anion perovskite, wherein the mixed-anion perovskite comprises two or more different anions selected from halide anions and chalcogenide anions. The invention further provides a mixed-halide perovskite of the formula (I) [A][B][X] 3 wherein: [A] is at least one organic cation; [B] is at least one divalent metal cation; and [X] is said two or more different halide anions. In another aspect, the invention provides the use of a mixed-anion perovskite as a sensitizer in an optoelectronic device, wherein the mixed-anion perovskite comprises two or more different anions selected from halide anions and chalcogenide anions. The invention also provides a photosensitizing material for an optoelectronic device comprising a mixed-anion perovskite wherein the mixed-anion perovskite comprises two or more different anions selected from halide anions and chalcogenide anions.
1. A photovoltaic device comprising:
a first electrode;
a second electrode; and, disposed between the first and second electrodes:
a sensitizer material which is capable of performing photoinduced charge generation within the photovoltaic device, wherein the sensitizer material is a mixed-halide perovskite of the formula (I)
[A][B][X] 3 (I)
wherein:
[A] is at least one cation, comprising at least one organic cation of the formula (R 5 R 6 N═CH—NR 7 R 8 ) + , wherein:
(i) R 5 is hydrogen, unsubstituted or substituted C 1 -C 20 alkyl, or unsubstituted or substituted aryl;
(ii) R 6 is hydrogen, unsubstituted or substituted C 1 -C 20 alkyl, or unsubstituted or substituted aryl;
(iii) R 7 is hydrogen, unsubstituted or substituted C 1 -C 20 alkyl, or unsubstituted or substituted aryl; and
(iv) R 8 is hydrogen, unsubstituted or substituted C 1 -C 20 alkyl, or unsubstituted or substituted aryl:
[B] is at least one divalent metal cation, wherein [B] comprises Pb 2+ ; and
[X] is two or more different halide anions, wherein one of said two or more different halide anions is iodide, and
a p-type layer which comprises a solid-state hole-transporting material which is not said perovskite.
2. A photovoltaic device according to claim 1 wherein the at least one organic cation of the formula (R 5 R 6 N═CH—NR 7 R 8 ) + is an organic cation of the formula (H 2 N═CH—NH 2 ) + .
3. A photovoltaic device according to claim 1 wherein [B] is Pb 2+ .
4. A photovoltaic device according to claim 1 wherein one of said two or more different halide anions is iodide and another of said two or more different halide anions is bromide.
5. A photovoltaic device according to claim 1 , wherein [X] is two or three different halide anions selected from fluoride, chloride, bromide or iodide.
6. A photovoltaic device according to claim 5 , wherein [X] is two different halide anions which are bromide and iodide.
7. A photovoltaic device according to claim 1 wherein the perovskite is a perovskite compound of formula (IIa):
ABX 3z X′ 3(1-z) (IIa)
wherein:
A is an organic cation of the formula (R 5 R 6 N═CH—NR 7 R 8 ) + , wherein:
(i) R 5 is hydrogen, unsubstituted or substituted C 1 -C 20 alkyl, or unsubstituted or substituted aryl;
(ii) R 6 is hydrogen, unsubstituted or substituted C 1 -C 20 alkyl, or unsubstituted or substituted aryl;
(iii) R 7 is hydrogen, unsubstituted or substituted C 1 -C 20 alkyl, or unsubstituted or substituted aryl; and
(iv) R 8 is hydrogen, unsubstituted or substituted C 1 -C 20 alkyl, or unsubstituted or substituted aryl;
B is Pb 2+ ;
X is a first halide anion wherein the first halide anion is iodide;
X′ is a second halide anion which is different from the first halide anion; and
z is greater than 0 and less than 1.
8. A photovoltaic device according to claim 7 , wherein X is iodide and X′ is bromide.
9. A photovoltaic device according to claim 7 wherein z is from 0.05 to 0.95.
10. A photovoltaic device according to claim 7 wherein the organic cation has the formula (H 2 N═CH—NH 2 ) + .
11. A photovoltaic device according to claim 7 wherein the perovskite has the formula (H 2 N═CH—NH 2 )PbI 3z Br 3(1-z) wherein z is greater than 0 and less than 1.
12. A photovoltaic device according to claim 11 wherein z is from 0.05 to 0.95.
13. A photovoltaic device according to claim 1 wherein the solid-state hole transporting material is a polymeric or molecular hole transporter.
14. A photovoltaic device comprising:
a first electrode;
a second electrode; and, disposed between the first and second electrodes:
(a) a p-type layer which comprises a solid-state hole transporting material, wherein the solid-state hole transporting material is a polymeric or molecular hole transporter which is not said perovskite; and
(b) a sensitizer material which is capable of performing photoinduced charge generation within the photovoltaic device, wherein the sensitizer material is a perovskite of the formula (I)
[A][B][X] 3 (I)
wherein:
[A] is at least one cation, comprising at least one organic cation of the formula (H 2 N═CH—NH 2 ) + ;
[B] is at least one divalent metal cation, wherein [B] comprises Pb 2+ ; and
[X] is iodide, or [X] is two or more different halide anions, wherein one of said two or more different halide anions is iodide.