Symmetry‐Reduction Enhanced Polarization‐Sensitive Photodetection in Core–Shell SbI₃/Sb₂O₃ van der Waals Heterostructure

Abstract

Structural symmetry is a simple way to quantify the anisotropic properties of materials toward unique device applications including anisotropic transportation and polarization‐sensitive photodetection. The enhancement of anisotropy can be achieved by artificial symmetry‐reduction design. A core–shell SbI3/Sb2O3 nanowire, a heterostructure bonded by van der Waals forces, is introduced as an example of enhancing the performance of polarization‐sensitive photodetectors via symmetry reduction. The structural, vibrational, and optical anisotropies of such core–shell nanostructures are systematically investigated. It is found that the anisotropic absorbance of a core–shell nanowire is obviously higher than that of two single compounds from both theoretical and experimental investigations. Anisotropic photocurrents of the polarization‐sensitive photodetectors based on these core–shell SbI3/Sb2O3 van der Waals nanowires are measured ranging from ultraviolet (UV) to visible light (360–532 nm). Compared with other van der Waals 1D materials, low anisotropy ratio (Imax/Imin) is measured based on SbI3 but a device based on this core–shell nanowire possesses a relatively high anisotropy ratio of ≈3.14 under 450 nm polarized light. This work shows that the low‐symmetrical core–shell van der Waals heterostructure has large potential to be applied in wide range polarization‐sensitive photodetectors.

Low‐Noise Dual‐Band Polarimetric Image Sensor Based on 1D Bi2S3 Nanowire

“…Optical absorbance is a positive correlation with the parameter R . [ 36 ] The distribution of charge density distribution along the a ‐axis and b ‐axis has different 〈 c | H eR | ν 〉, resulting from the different values of R for photon absorption per unit time in the a ‐axis and b ‐axis. The special bandgap and distinct optical absorption anisotropy in Bi 2 S 3 prompt us to further explore in‐plane photoelectric properties along with different directions.…”

Recent Progress in Anisotropic 2D Semiconductors: From Material Properties to Photoelectric Detection

“…Therefore, future research can pay attention to these questions to achieve high‐performance and flexible anisotropic photodetector. [ 119,120 ]…”

Van der Waals heterostructures with one-dimensional atomic crystals

“…heterostructures in core/shell geometry have lots of advantages compared with single type of materials, e.g., improvement of photoresponsivity and photoconductive gain, fast response speed, and broad detecting spectrum, enhancement of polarization sensitivity, etc. [226,[233][234][235] For example, due to enhanced anisotropy of distinction in charge density states, the 1D vdW SbI 3 /Sb 2 O 3 heteronanowire possesses a much higher absorbance dichroic ratio compared with the that of the two single compounds [236]. The phototransistor with this heterostructure exhibits an extremely high anisotropy ratio of photocurrent of up to 3.14 under 450 nm illumination, which is almost three times larger than that of pure SbI 3 devices (Fig.…”