Capillary-Bridge Controlled Patterning of BTR:PC71 BM Bulk Heterojunction Micro Arrays towards High-Performance Photodetector.

The patterning strategy of organic semiconductors is a crucial issue for integrated circuit. However, due to the uncontrollable liquid dewetting, most of the research is mainly focused on the patterning of single component, few works have been done on the patterning of multi-component or heterojunction, which play an important role in optoelectronic devices. Therefore, a capillary-bridge strategy was introduced for patterning of bulk heterojunction (BHJ) micro-arrays, with liquid crystalline BTR and PC71 BM utilized as donor and acceptor, respectively. The BTR:PC71 BM arrays presented hierarchical morphology with suitable phase separation, which contributes to the efficient charge generation and transport. Moreover, the photodetector exhibited excellent performance with the light on/off ratio greater than 2000, the responsivity of 40.57 A W-1 , and specific detectivity of 2.15×1012  Jones. Such progress demonstrates that the capillary-bridge strategy is a promising approach for the fabrication of high-quality BHJ micropatterns arrays.