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

Abstract

Few-layer transition metal dichalcogenides (TMDs) and their combination as van der Waals heterostructures provide a promising platform for high-performance optoelectronic devices. However, the ultrathin thickness of TMD flakes limits efficient light trapping and absorption, which triggers the hybrid construction with optical resonant cavities for enhanced light absorption. The optical structure enriched photodetectors can also be wavelength-and polarization-sensitive but require complicated fabrication. Herein, a new-type TMD-based photodetector embedded with nanoslits is proposed to enhance light trapping. Taking ReS 2 as an example, strong anisotropic Mie-type optical responses arising from the intrinsic in-plane anisotropy and nanoslit-enhanced anisotropy are discovered. Owing to the nanoslit-enhanced optical resonances and band engineering, excellent photodetection performances are demonstrated with high responsivity of 27 A W −1 and short rise/decay times of 3.7/3.7 ms. More importantly, through controlling the angle between the nanoslit orientation and the polarization direction to excite different resonant modes, polarization-sensitive photodetectors with anisotropy ratios from 5.9 to 12.6 can be achieved, representing one of the most polarization-sensitive TMD-based photodetectors. The depth and orientation of nanoslits are demonstrated crucial for optimizing the anisotropy ratio. The findings bring an effective scheme to construct high-performance and polarization-sensitive photodetectors.

ReS2 Nanosheet/WS2 Nanosheet/p-GaN Substrate Dual Junction Photodetectors

“…Additionally, Figure c displays the Raman spectra of the dual junction device at four different positions. The red and yellow curves represent the Raman spectra of the WS 2 and WS 2 /GaN regions, respectively, where two prominent peaks of E 2g and A 1g consistently appear, aligning with the typical Raman modes of WS 2 . − The green curve illustrates the Raman spectrum of the ReS 2 region, exhibiting a strong A g characteristic peak at 158.04 cm –1 along with other weaker Raman peaks. , The purple curve corresponds to the Raman spectrum of the ReS 2 /WS 2 /GaN region, demonstrating a combined peak of WS 2 and ReS 2 , indicating the successful production of high-quality vdWs heterostructures through the transfer process. High-resolution transmission electron microscopy (HRTEM) images in Figure S2 confirm the highly crystalline nature of the WS 2 and ReS 2 nanosheets.…”

“…40−42 The green curve illustrates the Raman spectrum of the ReS 2 region, exhibiting a strong A g characteristic peak at 158.04 cm −1 along with other weaker Raman peaks. 43,44 The purple curve corresponds to the Raman spectrum of the ReS 2 /WS 2 /GaN region, demonstrating a combined peak of WS 2 and ReS 2 , indicating the successful production of high-quality vdWs heterostructures through the transfer process. High-resolution transmission electron microscopy (HRTEM) images in Figure S2 confirm the highly crystalline nature of the WS 2 and ReS 2 nanosheets.…”

Magnetic Bimetallic Heterointerface Nanomissiles with Enhanced Microwave Absorption for Microwave Thermal/Dynamics Therapy of Breast Cancer

“…The presence of C, N, O, Zr, Ni, and Ru in MNRC was confirmed at first (Figure i), then peaks at 852.08/872.2 eV and 855.28/873.4 eV in the Ni 2p spectrum corresponded to Ni 0 and Ni 2+ , respectively, representing the presence of metallic Ni and Ni­(OH) 2 (Figure g), and peaks located at 279.8/284.2 eV and 280.2/286.0/288.7 eV in the Ru 3d spectrum represented metallic Ru and RuOx (Figure k), demonstrating that a large number of defects and metal oxides were generated by multiple redox reactions during the synthetic process and eventually led to the formation of multilayer heterogeneous interfaces. − Inspiritingly, these formed interfaces created favorable conditions for improving interfacial effects. In addition, MNRC exhibited the stronger vibrating sample magnetometer (VSM) coercivity than MNC due to compositional and microstructural differences in the local magnified view (Figure l), facilitating the higher anisotropy and then promoting the natural resonance enhancement. − Moreover, the elongated shape of MNRC’s VSM also enhanced the permeability value of the sample and improved magnetic loss performance (Figure S6), further determining the MA performance. In the end, the solubility of MNR and MNRC was compared after being left in H 2 O, PBS, and RPMI-1640 for 24 h (Figure S7), and most of the MNR had already precipitated to the bottom after 6 h, while there was no significant sediment in the MNRC group, fully demonstrating that the COF coating could significantly improve its biocompatibility and laying a foundation for its biological application.…”

Low‐Dimensional‐Materials‐Based Photodetectors for Next‐Generation Polarized Detection and Imaging

“…[ 47 ] To avoid repeating the content of other similar articles, here we provide a simple performance comparison of existing devices in Table 6 and Figure 8b. [ 23,25,26,140,178,180,181,197,213,216,217,251,256,259,260,263–296 ]…”