Polarization‐Resolved p‐Se/n‐WS₂ Heterojunctions toward Application in Microcomputer System as Multivalued Signal Trigger

Abstract

Polarization‐sensitive photodetectors based on van der Waals heterojunctions (vdWH) have excellent polarization‐resolved optoelectronic properties that can enable the applications in polarized light identification and imaging. With the development of optical microcomputer control systems (OMCS), it is crucial and energy efficient to adopt the self‐powered and polarization‐resolved signal‐generators to optimize the circuit design of OMCS. In this work, the selenium (Se) flakes with in‐plane anisotropy and p‐type character are grown and incorporated with n‐type tungsten disulfide (WS2) to construct the type‐II vdWH for polarization‐sensitive and self‐powered photodetectors. Under 405 nm monochrome laser with 1.33 mW cm−2 power density, the photovoltaic device exhibits superior photodetection performance with the photoelectric conversion efficiency (PCE) of 3.6%, the responsivity (R) of 196 mA W−1 and the external quantum efficiency (EQE) of about 60%. The strong in‐plane anisotropy of Se crystal structure gives rise to the capability of polarized light detection with anisotropic photocurrent ratio of ≈2.2 under the 405 nm laser (13.71 mW cm−2). Benefiting from the well polarization‐sensitive and photovoltaic properties, the p‐Se/n‐WS2 vdWH is successfully applied in the OMCS as multivalued signal trigger. This work develops the new anisotropic vdWH and demonstrates its feasibility for applications in logic circuits and control systems.

Van der Waals Heterostructures With Built‐In Mie Resonances For Polarization‐Sensitive Photodetection

“…Achieving the detection of polarized light is significant for polarization imaging, target tracking, and remote sensing. [9] Fortunately, some TMDs such as ReS 2 with intrinsic inplane anisotropy [10][11][12] enrich the devices for polarization-sensitive detection. [13][14][15][16] Utilizing intrinsic anisotropy to realize polarization detection is insensitive; so, this limitation triggers the combination of TMDs with metallic plasmonic structures [17][18][19] or dielectric Mie-type structures [20][21][22][23] to enhance light-matter interactions.…”

Self-Powered Photodetector with High Efficiency and Polarization Sensitivity Enabled by WSe2/Ta2NiSe5/WSe2 van der Waals Dual Heterojunction

“…We finally present the superiority of our DHJ device for high efficiency and high polarization-sensitive photodetection by comparing its EQE and polarization sensitivity with currently reported photodetectors under self-powered mode, as summarized in Figure f. It can be seen that the DHJ device not only shows both superior self-powered photodetection efficiency and polarization sensitivity compared with the SHJ device but also far exceeds most state-of-the-art 2D material-based self-powered photodetector under visible light illumination. ,,,,,− As a result, the WSe 2 /Ta 2 NiSe 5 /WSe 2 DHJ device is a potentially promising candidate for the self-powered photodetector with high efficiency and polarization sensitivity.…”

Van der Waals Integrated LiNbO3/WS2 for High‐Performance UV–Vis–NIR Photodetection

“…This means that pristine WS 2 cannot be used for polarization detection, which is consistent with other reports. [73] Figure 5d presents a reasonable understanding of this phenomenon, when the linearly polarized light is incident on the x-cut LN at angle 𝛼 and angle 𝛽, respectively, the degree of attenuation of the spontaneous polarization of the x-cut LN will be different, [74,75] which would further influent the amount of surface charges that can be released and injected into WS 2 for doping via the pyroelectric effect, and the polarization dependent carrier concentration would lead to the vibration of the output current, forming eight-shaped polarization-dependent characteristics.…”