N-type dopants for efficient solar cells
Triazabicylodecene can effectively n-dope a variety of organic semiconductors, including PCBM, thus increasing in-plane conductivities. We synthesized a series of TBD-based n-dopants via an N-alkylation reaction and studied the effect of various alkyl chains on the physical and device properties of the dopants. Combining two TBD moieties on a long alky chain gave a solid dopant, 2TBD-C10, with high thermal stability above 250° C. PCBM films doped by 2TBD-C10 were the most tolerant to thermal annealing and reached in-plane conductivities of 6.5×10 −2 S/cm. Furthermore, incorporating 2TBD-C10 doped PCBM as the electron transport layer (ETL) in methylammonium lead triiodide (MAPbI 3 ) based photovoltaics led to a 23% increase in performance, from 11.8% to 14.5% PCE.
1. A composition of matter, comprising:
an organic compound of the structure:
wherein:
1≤m≤8;
1≤n≤8;
2≤x≤4; and
R is any substituted or non-substituted alkyl, alkenyl, alkynyl, aryl or alkoxy group; and
the
comprises an n-type dopant.
2. The composition of matter of claim 1 , wherein R contains one or more heteroatoms.
3. The composition of matter of claim 1 , wherein R contains one or more aromatic moieties.
4. The composition of matter of claim 1 , wherein:
is any of the following bicyclic structures:
5. The composition of matter of claim 1 , wherein the organic compound is a dimer (x=2) wherein each end of the R is connected to one of the
6. The composition of matter of claim 5 , wherein the organic
compound is
7. The composition of matter of claim 1 , wherein the organic compound is a trimer (x=3) wherein each end of the R is connected to one of the
8. The composition of matter of claim 1 bonded to a phenyl-C 61 -butyric acid methyl ester (PCBM), or wherein the R comprises the PCBM, so as to n-type dope the PCBM.
9. The composition of matter of claim 1 bonded to an electron acceptor, or wherein the R comprises an electron acceptor, so as to n-type dope the acceptor.
10. The composition of claim 1 bonded to a fullerene so as to form the organic compound
11. The composition of matter of claim 1 , wherein the R is selected so that the organic compound is miscible with an organic acceptor.
12. The composition of matter of claim 11 , further comprising a single phase amorphous composition including the organic compound combined with the organic acceptor, wherein the organic compound n-type dopes the organic acceptor.
13. The composition of matter of claim 1 , wherein the
comprises an n-type dopant for the R.
14. A composition of matter, comprising an organic compound of the structure:
15. A composition of matter comprising an organic compound of the structure
wherein:
1≤m≤8;
1≤n≤8;
2≤x≤4; and
R is any substituted or non-substituted alkyl, alkenyl, alkynyl, aryl or alkoxy group; and
the R comprises the fullerene, so as to n-type dope the fullerene.