Self-doping small molecular conjugated electrolytes enabled by n-type side chains for highly efficient non-fullerene polymer solar cells

We developed a series of novel small molecular conjugated electrolytes (SMCEs) via side chain engineering. The introduced n-type 1,3,4-thiadiazole/1,3,4-oxadiazole side chains featured the related SMCEs with self-doping nature and high electron conductive property. On using as cathode interlayers in non-fullerene-polymer solar cells, a high power conversion efficiency (PCE) of up to 13.21% was achieved with an excellent thickness-insensitive property.