ORGANIC SOLAR CELL AND PHOTODETECTOR MATERIALS AND DEVICES
Narrow bandgap n-type small molecules are attracting attention in the near-infrared organic optoelectronics field, due to their easy tunable energy band with a molecular design flexibility. However, only a few reports demonstrate narrow bandgap non-fullerene acceptors (NFAs) that perform well in organic solar cells (OSCs), and the corresponding benefits of NFA photodiodes have not been well investigated in organic photodetectors (OPDs). Here, the ultra-narrow bandgap NFAs CO1-4F, CO1-4Cl and o-IO1 were designed and synthesized for the achieved efficient near-infrared organic photodiodes such as solar cells and photodetectors. Designing an asymmetrical CO1-4F by introducing two different π-bridges including alkylthienyl and alkoxythienyl units ultimately provides an asymmetric A-D′-D-D″-A molecular configuration. This enables a delicate modulation in energy band structure as well as maintains an intense intramolecular charge transfer characteristic of the excited state.
1 . A device, comprising:
an active region including an electron acceptor and an electron donor, the electron acceptor comprising:
an organic semiconducting molecule having an A-D′-D-D″-A structure, wherein:
D′ is a first donor moiety,
D is a second donor moiety different from D′,
D″ is a third donor moiety different from D and D′, and
A is an acceptor moiety.
2 . The device of claim 1 , wherein:
the active region comprises each of the electron acceptors forming a heterojunction with the electron donor comprising a second organic semiconducting molecule, and
the active region has a thickness of at least 300 nanometers or in a range of 200 nm to 1 micrometer.
3 . The device of claim 1 , further comprising:
a cathode;
an anode; and
the active region between the cathode and the anode; and wherein:
holes and electrons are generated in the active region in response to electromagnetic radiation incident on the active region,
the electrons are collected in the electron acceptor and are transmitted through to the cathode, and
the holes are collected in the electron donor and transmitted through to the anode.
4 . The device of claim 3 , further comprising:
a hole blocking layer between the cathode and the active region, and
an electron blocking layer between the anode and the active region.
5 . The device of claim 1 , wherein the device is a photodetector outputting current in response to infrared electromagnetic radiation absorbed in the active region.
6 . The device of claim 1 , wherein each of the electron donors comprise at least one compound selected from PTB7-Th, another BDT based polymer, a CPDT based polymer, a DPP based polymer, or a DTP based polymer.
7 . The device of claim 1 , further comprising:
a plurality of the electron donors and a plurality of the organic semiconducting molecules that are phase separated, wherein the organic semiconducting molecules are disposed in a hierarchical network and the electron donors comprising the second organic semiconducting molecules occupy spaces in the hierarchical network, and wherein the hierarchical network comprises larger mid rib shaped regions connected by smaller or thinner regions.
8 . The device of claim 1 , wherein
D′ and D″ are selected from:
and
wherein each R 2 , R 3 , R 4 , R 5 , R 6 is independently hydrogen or substituted or non-substituted alkyl, aryl or alkoxy chain; Z is O, S, Se, or N—R 6 , R 4 can be Z—R 2 ; R 5 can be the same as R 3 ; Y is O, S, Se, or N—R 6 and R 3 is different from Z—R 2 .
wherein D is one of the following:
where each R 1 and R 3 is independently hydrogen or a substituted or non-substituted alkyl, aryl or alkoxy chain; X is C, Si, Ge, N or P; Y is O, S, Se or N—R 3 ; each Ar is independently a substituted or non-substituted aromatic functional group, or each Ar is independently nothing and the valence of its respective thiophene ring is completed with hydrogen, or
wherein D is one of the following:
where each R 1 is independently hydrogen or a substituted or non-substituted alkyl, aryl or alkoxy chain; X is C, Si, Ge, N or P; and Y is O, S, Se or N—R 3 , or
wherein D is one of the following:
where each R, R 1 , R 2 and R 3 is independently hydrogen or a substituted or non-substituted alkyl, aryl or alkoxy chain; X is C, Si, Ge, N or P; and Y is O, S, Se or N—R 3 .
9 . The device of claim 1 , wherein:
A has the structure:
where
X 1 , X 2 or X 3 halogen, CN or alkoxy, alkylthio or N- or S-annulated
Y 1 , Y 2 , Y 3 or Y 4 =S or O
R 1 or R 2 =H or solubilizing chain or
where
Y or Z=CH, CF, N, C—CN or C—OR
X=O, S, Se or N—R where R is H or solubilizing chain or
where
R 1 or R 2 =H or any sort of solubilizing chain
Ar=any sort of aryl unit
where
wherein EWG is any electron withdrawing group, or
where
X 1 or X 2 =O, S, malonitrile
Y=Halogen, —CN or any solubilizing chain
(any number of substituents)
Ar=any sort of aryl unit
X 1 or X 2 methyl or trifluoromethyl or
where
Y 1 , Y 2 or Y 3 =O, S, malonitrile
R, R 1 and R 2 =any solubilizing chain or H or
where
R=H or any solubilizing chain or
X=O, S, Se
R=H or any solubilizing chain or
where
R=H or any solubilizing chains
Y 1 or Y 2 =S, O or malonitrile
Ar=any aryl unit or
10 . The device of claim 1 , wherein A is an acceptor moiety comprising (3-oxo-2,3-dihydro-1H-inden-1-ylidene)malononitrile (IC).”
11 . The device claim 1 , wherein:
D′ is a donor moiety comprising an alkoxythienyl,
D is a donor moiety comprising a dithiophene, and
D″ is a donor moiety comprising an alkylthienyl, and
A is an acceptor moiety comprising (3-oxo-2,3-dihydro-1H-inden-1-ylidene)malononitrile (IC).
12 . The composition of matter of claim 1 , wherein the organic semiconducting molecule has a HOMO in a range of −5.0 eV to −5.5 eV, a LUMO in a range of −3.8 eV to −4.3 eV, and a bandgap in a range of 1.0 eV to 1.4 eV.
13 . The device of claim 1 , wherein D is one of the following:
where each R 1 and R 3 is independently hydrogen or a substituted or non-substituted alkyl, aryl or alkoxy chain; X is C, Si, Ge, N or P; Y is O, S, Se or N—R 3 ; each Ar is independently a substituted or non-substituted aromatic functional group, or each Ar is independently nothing and the valence of its respective thiophene ring is completed with hydrogen, or
wherein D is one of the following:
where each R 1 is independently hydrogen or a substituted or non-substituted alkyl, aryl or alkoxy chain; X is C, Si, Ge, N or P; and Y is O, S, Se or N—R 3 , or
wherein D is one of the following:
where each R, R 1 , R 2 and R 3 is independently hydrogen or a substituted or non-substituted alkyl, aryl or alkoxy chain; X is C, Si, Ge, N or P; and Y is O, S, Se or N—R 3 .
14 . The device of claim 1 ,
wherein A has the structure (and isomers thereof):
wherein EWG is any electron withdrawing group.
15 . The device of claim 1 , wherein D′ and D″ are selected from:
where each R 2 , R 3 , R 4 , R 5 , R 6 is independently hydrogen or a substituted or non-substituted alkyl, aryl or alkoxy chain; R 4 can be Z—R 2 ; R 5 can be the same as R 3 ; and Y is O, S, Se, or N—R 6 ; and
wherein A has the structure (and isomers thereof):
wherein EWG is any electron withdrawing group.
16 . The device of claim 1 , wherein the organic semiconducting molecule has the structure (or an isomer thereof):
where each R 1 is independently hydrogen or a substituted or non-substituted alkyl, aryl or alkoxy chain; X is C, Si, Ge, N or P; and each Ar is independently a substituted or non-substituted aromatic functional group or each Ar is independently nothing and the valence of its respective thiophene ring is completed with hydrogen.
17 . The device of claim 1 , wherein the organic semiconducting molecule has the structure (or isomers thereof):
where each R 1 , R 2 , R 3 , R 4 , R 5 , R 6 is independently hydrogen or a substituted or non-substituted alkyl, aryl or alkoxy chain but R 3 is different from Z—R 2 ; R 4 can be the same as Z—R 2 ; R 5 can be the same as R 3 ; X is C, Si, Ge, N or P; Y is O, S, Se, or N—R 6 , Z is O, S, Se, or N—R 6 ; each Ar is independently a substituted or non-substituted aromatic functional group, or each Ar is independently nothing and the valence of its respective thiophene ring is completed with hydrogen.
18 . A composition of matter, comprising:
an organic semiconducting molecule having an A-D′-D-D″-A structure, wherein:
D′ is a first donor moiety,
D is a second donor moiety different from D′,
D″ is a third donor moiety different from D and D′ to make the organic semiconducting molecule asymmetric, and
A is an acceptor moiety having the structure:
where
X 1 , X 2 or X 3 halogen, CN or alkoxy, alkylthio or N- or S-annulated
Y 1 , Y 2 , Y 3 or Y 4 =S or O
R 1 or R 2 =H or solubilizing chain or
where
Y or Z=CH, CF, N, C—CN or C—OR
X=O, S, Se or N—R where R is H or solubilizing chain or
where
R 1 or R 2 =H or any sort of solubilizing chain
Ar=any sort of aryl unit or
where
wherein EWG is any electron withdrawing group, or
where
X 1 or X 2 =O, S, malonitrile
Y=Halogen, —CN or any solubilizing chain
(any number of substituents)
Ar=any sort of aryl unit
X 1 or X 2 =methyl or trifluoromethyl or
where
Y 1 , Y 2 or Y 3 =Q S or malonitrile
R, R 1 , and R 2 =any solubilizing chain or H or
where
R=H or any solubilizing chain or
X=S, Se
R=H or any solubilizing chain or
where
R=H or any solubilizing chains
Y 1 or Y 2 =S, O or malonitrile
Ar=any aryl unit or
19 . The composition of matter of claim 18 wherein:
wherein D′ and D″ are selected from:
and
wherein each R 2 , R 3 , R 4 , R 5 , R 6 is independently hydrogen or a substituted or non-substituted alkyl, aryl or alkoxy chain; Z is O, S, Se, or N—R 6 , R 4 can be Z—R 2 ; R s can be the same as R 3 ; Y is O, S, Se, or N—R 6 and R 3 is different from Z—R 2 .
wherein D is one of the following:
where each R 1 and R 3 is independently hydrogen or a substituted or non-substituted alkyl, aryl or alkoxy chain; X is C, Si, Ge, N or P; Y is O, S, Se or N—R 3 ; each Ar is independently a substituted or non-substituted aromatic functional group, or each Ar is independently nothing and the valence of its respective thiophene ring is completed with hydrogen, or
wherein D is one of the following:
where each R 1 is independently hydrogen or a substituted or non-substituted alkyl, aryl or alkoxy chain; X is C, Si, Ge, N or P; and Y is O, S, Se or N—R 3 , or
wherein D is one of the following:
where each R, R 1 , R 2 and R 3 is independently hydrogen or a substituted or non-substituted alkyl, aryl or alkoxy chain; X is C, Si, Ge, N or P; and Y is O, S, Se or N—R 3 .