Asymmetric Wettability Mediated Patterning of Single Crystalline Nematic Liquid Crystal and P-N Heterojunction Toward a Broadband Photodetector.

Abstract

The well aligned and precise patterning of liquid crystals (LCs) are considered as two key challenges for large-scale and high-efficiency integrated optoelectronic devices. However, owing to the uncontrollable liquid flow and dewetting process in the conventional techniques, most of the reported research is mainly focused on simple sematic LCs, which are composed of terthiophenes or benzothieno[3, 2-b][1] benzothiophene backbone; only a few works are carried out on the complicated LCs. Herein, an efficient strategy was introduced to control the liquid flow and alignment of LCs and realized precise and high-quality patterning of A-π-D-π-A BTR, based on the asymmetric wettability interface. Through this strategy, the large-area and well-aligned BTR microwires array was fabricated, which exhibited highly ordered molecular packing and improved charge transport performance. Furthermore, the integration of BTR and PC71BM was achieved to manufacture uniform P-N heterojunction arrays, which still possessed highly ordered alignment of BTR. On the basis of these aligned heterojunction arrays, the high-performance photodetector exhibited an excellent responsivity of 27.56 A W-1 and a specific detectivity of 2.07 × 1012 Jones. This research not only provides an efficient strategy for the fabrication of aligned micropatterns of LCs but also gives a novel insight for the fabrication of high-quality micropatterns of the P-N heterojunction toward integrated optoelectronics.