SOLUTION PROCESSED METAL OXIDE THIN FILM HOLE TRANSPORT LAYERS FOR HIGH PERFORMANCE ORGANIC SOLAR CELLS
A method for the application of solution processed metal oxide hole transport layers in organic photovoltaic devices and related organic electronics devices is disclosed. The metal oxide may be derived from a metal-organic precursor enabling solution processing of an amorphous, p-type metal oxide. An organic photovoltaic device having solution processed, metal oxide, thin-film hole transport layer.
1 . A method for fabricating an organic photovoltaic device, the method comprising:
forming a substrate;
forming an ITO layer on the substrate, wherein the ITO layer comprises an anode;
forming an HTL layer on the ITO layer, wherein the HTL layer comprises an amorphous, p-type metal oxide;
forming an active layer on the HTL layer, wherein the active layer comprises a donor region and an acceptor region; and
forming a contact on the active layer, wherein the contact comprises a cathode.
2 . The method according to claim 1 , wherein the donor region of the active layer comprises a polymer and wherein the acceptor region of the active layer comprises a fullerene.
3 . The method according to claim 2 , wherein the donor region of the active layer comprises P3HT and wherein the acceptor region of the active layer comprises PCBM.
4 . The method according to claim 1 , wherein the HTL layer comprises p-NiO.
5 . The method according to claim 1 , wherein the HTL layer comprises sNiO.
6 . The method according to claim 5 , wherein the sNiO is formed by solution deposited NiO followed by a low temperature anneal.
7 . The method according to claim 6 , wherein the sNiO is formed by spin-coating a diluted nickel ink followed by a low temperature anneal.
8 . The method according to claim 6 , wherein the sNiO is formed by spin-coating a diluted nickel ink at approximately 4000 rpm for approximately 60 seconds, followed by annealing at approximately 250° C. for approximately 1 hour.
9 . The method according to claim 6 , wherein the sNiO is formed by spin-coating a nickel ink at approximately 4000 rpm, followed by annealing on a low temperature hot plate in air.
10 . The method according to claim 5 , wherein the sNiO comprises a thin-film.
11 . The method according to claim 10 , wherein the thin-film sNiO is approximately 10 nm.
12 . The method according to claim 1 , wherein the HTL layer comprises p-NiO and the active layer comprises a PCDTBT/PCBM bulk heterojunction.
13 . The method according to claim 1 further comprising: exposing the HTL layer to oxygen plasma after the HTL layer is formed.
14 . The method according the claim 1 further comprising: exposing the HTL layer to an O 2 -plasma treatment after the HTL layer is formed.
15 . A method for fabricating an organic photovoltaic device, the method comprising:
forming a substrate;
forming an TCO layer on the substrate, wherein the TCO layer comprises an anode;
forming an HTL layer on the TCO layer, wherein the HTL layer comprises an amorphous, p-type metal oxide, wherein the HTL layer is formed from a metal-precursor via solution processing of the amorphous, p-type metal oxide;
forming an active layer on the HTL layer, wherein the active layer comprises a donor region and an acceptor region; and
forming a contact on the active layer, wherein the contact comprises a cathode.
16 . The method according to claim 15 , wherein the HTL layer is formed via solution processing of a metal-organic ink:
17 . The method according to claim 15 , wherein the HTL layer is formed via solution processing of a metal-organic ink using ink-jet or continuous flow printing.
18 . The method according to claim 17 , wherein the metal-organic ink comprises a complex in which a metal in solution coordinates to one or more diamine groups suspended in a solvent.
19 . The method according to claim 16 , further comprising annealing the metal-organic ink in air at elevated temperatures after the solution processing.
20 . The method according to claim 15 , wherein the TCO comprises a ZnO-based material.
21 . The method according to claim 20 , wherein the TCO comprises gallium-doped ZnO.
22 . The method according to claim 20 , wherein the TCO comprises aluminum-doped ZnO.
23 . The method according to claim 15 further comprising: exposing the HTL layer to an O 2 -plasma treatment after the HTL layer is formed.
24 . An organic photovoltaic device comprising:
a substrate;
a TCO layer on the substrate, wherein the TCO is configured to act as an anode;
an HTL layer on the TCO layer, wherein the HTL layer comprises an amorphous, p-type metal oxide thin film;
an active layer on the TCO layer, wherein the active layer comprises a donor region and an acceptor region; and
a cathode on the active layer.
25 . The organic photovoltaic device according to claim 24 , wherein the HTL layer comprises amorphous, p-type NiO.
26 . The organic photovoltaic device according to claim 24 , wherein the HTL layer comprises a spinel structure.
27 . The organic photovoltaic device according to claim 26 , wherein the HTL layer comprises Co(Ni)Zn2O4.
28 . The organic photovoltaic device according to claim 24 , wherein the HTL layer comprises a delafossite structure.
29 . The organic photovoltaic device according to claim 28 , wherein the HTL layer comprises CuAlOx.
30 . The organic photovoltaic device according to claim 24 , wherein the HTL layer is formed from a metal-organic ink using direct write solution processing via ink-jet or continuous flow printing followed by annealing in air at elevated temperatures.
31 . The organic photovoltaic device according to claim 24 , wherein the TCO layer comprises a ZnO-based material and the HTL comprises amorphous, p-type NiO.
32 . The organic photovoltaic device according to claim 24 , wherein the active layer comprises a PCDTBT:PC 70 BM bulk heterojunction.
33 . The organic photovoltaic device according to claim 24 , wherein the active layer comprises P3HT:PCBM.
34 . The organic photovoltaic device according to claim 24 , wherein the HTL layer comprises an oxygen plasma treated thin film NiO layer.