BTP-eC9 is a family member of the Y series of n-type non-fullerene semiconducting acceptors. It has been proven that these NFAs can achieve high device performance in non-fullerene polymer solar cells (NF-PSCs).
With a fused thienothienopyrrolo-thienothienoindole (TTP-TTI) core, BTP-eC9 is a modified version of Y7 but with better solubility. Comparing to Y6, chlorination at the peripheral end-groups can efficiently lower HOMO/LUMO energy levels. C–Cl bond also has a large dipole moment, expanding the absorption range further to near infrared (NIR) region.
A device efficiency approaching 18% has been reported using BTP-eC9 as the electron acceptor and PBDB-T-2F (PM6) as electron donor in single junction organic photovoltaic cells.
Device structure: ITO/PEDOT:PSS/PBDB-T-2F:BTP-eC9 (1:1.2)/PFN-Br/Al
| Thickness (nm) | VOC (V) | JSC (mA cm-2) | FF (%) | PCE (%) |
| 100 | 0.839 | 26.2 | 81.1 | 17.8 |
General Information
| Full name | 2,2'- [[12,13-Bis(2-butyloctyl)-12,13-dihydro-3,9-dinonylbisthieno[2'',3'':4',5']thieno[2',3':4,5]pyrrolo[3,2-e:2',3'-g][2,1,3]benzothiadiazole-2,10-diyl]bis[methylidyne(5,6-chloro-3-oxo-1H-indene-2,1(3H)-diylidene) ]]bis[propanedinitrile] |
| Synonyms | eC9, BTP-eC9 |
| Chemical formula | C86H94Cl4N8O2S5 |
| Molecular weight | 1573.89 g/mol |
| CAS number | n.a. |
| HOMO / LUMO | HOMO = -5.64 eV, LUMO = -4.05 eV [1] |
| Solubility | Chloroform, chlorobenzene and dichlorobenzene |
| Form | Dark blue powder/crystal |
| Classification / Family | BTP series NFAs, n-type non-fullerene electron acceptors, Organic semiconducting materials, Low band-gap small molecule, Small molecular acceptor, Organic photovoltaics, Polymer solar cells, NF-PSCs. |