Polarization conversion in bottom-up grown quasi-1D fibrous red phosphorus flakes.

Sun, Zhaojian; Chen, Wujia; Zhang, Bowen; Gao, Lei; Tao, Kezheng; Li, Qiang; Sun, Jia-Lin; Yan, Qingfeng · Nat Commun · 2023

basic_science · Level V

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Abstract

Fibrous red phosphorus (RP) has triggered growing attention as an emerging quasi-one-dimensional (quasi-1D) van der Waals crystal recently. Unfortunately, it is difficult to achieve substrate growth of high-quality fibrous RP flakes due to their inherent quasi-1D structure, which impedes their fundamental property exploration and device integration. Herein, we demonstrate a bottom-up approach for the growth of fibrous RP flakes with (001)-preferred orientation via a chemical vapor transport (CVT) reaction in the P/Sn/I<sub>2</sub> system. The formation of fibrous RP flakes can be attributed to the synergistic effect of Sn-mediated P<sub>4</sub> partial pressure and the SnI<sub>2</sub> capping layer-directed growth. Moreover, we investigate the optical anisotropy of the as-grown flakes, demonstrating their potential application as micro phase retarders in polarization conversion. Our developed bottom-up approach lays the foundation for studying the anisotropy and device integration of fibrous red phosphorus, opening up possibilities for the two-dimensional growth of quasi-1D van der Waals materials.