초록 |
When designing organic semiconductors, side chain engineering is as important as modifying the conjugated backbone. We have developed three dicyanovinyl-end capped donoracceptor diketopyrrolopyrrole-based n-type small molecules (C2C9CN, SiC4CN, and EH4PCN) bearing an identical length of alkyl spacer yet different end-functionalized side chains (i.e., alkyl-, siloxane-, and phosphonate-end pendants). In comparison with the alkyl-end side chains, incorporating siloxane-end side chains into the backbone facilitates 2D edge-on oriented high intergrain connectivity/crystallinity and compatibility with the substrate surface, whereas the phosphonate-end analogs have an adverse effect on the film-forming quality due to high polarity. This study contributes to our understanding of the role of the end-functionalized side chains for the development of high-performance semiconductors. |