Dopant-free polymeric hole-transporting materials for perovskite solar cell

Patent metadata

Field	Value
Publication number	US-10115917-B2
Application number	US-201615157778-A
Country	US
Kind code	B2
Filing date	May 18, 2016
Priority date	May 19, 2015
Publication date	Oct 30, 2018
Grant date	Oct 30, 2018

Abstract

The present teachings relate to hybrid organic-inorganic perovskite solar cells including a hole-transport layer in contact with the perovskite light-absorbing layer, where the hole-transport layer (HTL) is a pristine (undoped) polymer. More specifically, the HTL comprises a copolymer including a benzo[1,2-d;4,5-d′]bistriazole-containing repeating unit and a benzo[1,2-b:4,5-b′]dithiophene-containing repeating unit.

First claim

What is claimed is:

1. A hybrid organic-inorganic perovskite photovoltaic device comprising a first electrode, a second electrode, a light-absorbing layer between the first and second electrodes that comprises a perovskite compound, and a hole-transporting material in contact with the perovskite compound, wherein the hole-transporting material comprises a copolymer comprising a benzo[1,2-d;4,5-d′]bistriazole-containing repeating unit and a benzo[1,2-b:4,5-b′]dithiophene-containing repeating unit.

2. The device of claim 1 , wherein the copolymer comprises a repeating unit represented by formula (I):

wherein:
R 1 , at each occurrence, independently is a solubilizing group;
R 2 , at each occurrence, independently is selected from the group consisting of H, F, Cl, CN, and a C 1-40 alkyl or haloalkyl group;
R 3 and R 4 , at each occurrence, independently are selected from the group consisting of H, F, Cl, and -L-(Ar) m -L′-R 5 , wherein L and L′, independently are selected from the group consisting of —O—, —S—, —Se—, —C(O)—, —OC(O)—, —C(O)O—, a divalent C 1-40 alkyl or haloalkyl group, and a covalent bond; R 5 is a solubilizing group; Ar, at each occurrence, independently is a C 6-14 aryl group or a 5-14 membered heteroaryl group, each of which optionally is substituted with 1-4 -L′-R 5 groups; and m is 0, 1, 2, 3 or 4; and
q and q′ independently are 0, 1, 2, 3 or 4.

3. The device of claim 2 , wherein each of the solubilizing group independently is selected from the group consisting of a C 3-40 alkyl group, a C 3-40 alkenyl group, and a C 3-40 haloalkyl group.

4. The device of claim 2 , wherein the copolymer comprises a repeating unit represented by formula (II):

wherein each R 1 is a C 3-40 alkyl group.

5. The device of claim 4 , wherein each R 3 is an —O—C 3-40 alkyl group.

6. The device of claim 4 , wherein each R 3 is a C 3-40 alkyl group.

7. The device of claim 4 , wherein each R 3 is —(Ar)-L′-R 5 , wherein Ar is a thienyl or phenyl group, L′ is O or a covalent bond; and R 5 is a C 3-40 alkyl group.

8. The device of claim 7 , wherein each R 3 is a -phenyl-O—C 3-40 alkyl group.

9. The device of claim 7 , wherein each R 3 is a -thienyl-C 3-40 alkyl group.

10. The device of claim 1 , wherein the hole-transporting material is free of any dopants.

11. The device of claim 1 , wherein the hole-transporting material is free of a dopant selected from the group consisting of 4-tert-butylpyridine (TBP), bis(trifluoromethane)sulfonimide lithium salt (Li-TFSI), and tris(2-(1H-pyrazol-1-yl)4-tert-butylpyridine)cobalt(III) tris(bis(trifluoromethylsulfonyl)imide) (FK209).

12. The device of claim 1 , wherein the perovskite compound has the formula ABX 3 , wherein A is CH 3 NH 3 + or HN═CHNH 3 + , B is Sn 2 + or Pb 2 + , and each X independently is selected from I − , Br − , and Cl − .

13. The device of claim 12 , wherein the perovskite compound is CH 3 NH 3 PbI 3 or CH 3 NH 3 PbI 3-x Cl x , where x is 1 or 2.

14. The device of claim 1 having a planar structure, wherein the light-absorbing layer is a thin film comprising the perovskite compound.

15. The device of claim 14 further comprising a blocking layer between one of the first and second electrodes and the light-absorbing layer.

16. The device of claim 15 , wherein the blocking layer comprises TiO 2 or ZnO.

17. The device of claim 14 comprising a transparent conducting oxide as the first electrode, wherein the transparent conducting oxide is fluorine-doped tin oxide (FTO).

18. The device of claim 14 comprising a metal as the second electrode, wherein the metal is Au or Ag.

Assignees

• Univ Northwestern

Inventors

• Marks Tobin J
• Chang Robert P H
• Tam Teck Lip Dexter
• Liao Hsueh-Chung
• Facchetti Antonio

Classifications

• H01L51/442

  Electricity · mapped topic

• C08G2261/3223

  containing one or more sulfur atoms as the only heteroatom, e.g. thiophene · CPC title

• C08G2261/364

  containing hetero atoms · CPC title

• C08G61/126 Primary

  with a five-membered ring containing one sulfur atom in the ring · CPC title

• C08G61/123

  derived from five-membered heterocyclic compounds · CPC title