Organic ternary solar cells and vacuum-deposited method
View Patent ↗A method of making a photovoltaic cell comprises the steps of providing a substrate in a vacuum, depositing an anode over the substrate, depositing a first heterojunction layer over the anode layer, depositing a second heterojunction layer over the first heterojunction layer, depositing a cathode over the second heterojunction layer, and releasing the vacuum. A photovoltaic cell is also described.
1. A photovoltaic cell comprising:
an anode;
a cathode;
a first binary bulk heterojunction positioned between the anode and the cathode, comprising a first donor material and a first acceptor material; and
a second binary bulk heterojunction positioned between the first binary bulk heterojunction and the cathode, in direct contact with the first binary bulk heterojunction, comprising a second donor material and the first acceptor material;
wherein the second donor material has a Highest Occupied Molecular Orbital (HOMO) energy level closer to a vacuum level than a HOMO energy level of the first donor material, and wherein the second donor material has a Lowest Unoccupied Molecular Orbital (LUMO) energy level closer to the vacuum level than a LUMO energy level of the first donor material; and
wherein the first donor material and the second donor material are dipolar.
2. The photovoltaic cell of claim 1 , wherein the first acceptor material comprises a fullerene acceptor material.
3. The photovoltaic cell of claim 2 , wherein the first acceptor material comprises C 70 fullerene.
4. The photovoltaic cell of claim 1 , wherein the first acceptor material comprises a non-fullerene acceptor material.
5. The photovoltaic cell of claim 1 , further comprising a third binary bulk heterojunction positioned between the second binary bulk heterojunction and the cathode, comprising a third donor material and a third acceptor material.
6. The photovoltaic cell of claim 1 , wherein the first donor material comprises iBuBTDC.
7. The photovoltaic cell of claim 6 , wherein the second donor material comprises DTDCPB.
8. The photovoltaic cell of claim 1 , wherein the first donor material comprises DTDCPB.
9. The photovoltaic cell of claim 1 , wherein the first donor material and the second donor material absorb at one or more overlapping wavelengths.
10. A photovoltaic cell produced by a method comprising the steps of:
providing a substrate in a vacuum;
depositing an anode over the substrate;
depositing a first heterojunction layer over the anode layer;
depositing a second heterojunction layer directly on the first heterojunction layer;
depositing a cathode over the second heterojunction layer; and
releasing the vacuum;
the photovoltaic cell comprising:
the anode;
the cathode;
the first heterojunction positioned between the anode and the cathode, comprising a first donor material and a first acceptor material; and
the second heterojunction positioned between the first binary bulk heterojunction and the cathode, comprising a second donor material and the first acceptor material;
wherein the second donor material has a Highest Occupied Molecular Orbital (HOMO) energy level closer to a vacuum level than a HOMO energy level of the first donor material, and wherein the second donor material has a Lowest Unoccupied Molecular Orbital (LUMO) energy level closer to the vacuum level than a LUMO energy level of the first donor material; and
wherein the first donor material and the second donor material are dipolar.
11. The photovoltaic cell of claim 10 , wherein the photovoltaic cell has a power conversion efficiency of at least 10%.