Hybrid 1D/2D heterostructure with electronic structure engineering toward high-sensitivity and polarization-dependent photodetector

Abstract

The widespread application of photodetectors has triggered an urgent need for high-sensitivity and polarization-dependent photodetection. In this field, the two-dimensional (2D) tungsten disulfide (WS 2 ) exhibits intriguing optical and electronic properties, making it an attractive photosensitive material for optoelectronic applications. However, the lack of an effective built-in electric field and photoconductive gain mechanism in 2D WS 2 impedes its application in high-performance photodetectors. Herein, we propose a hybrid heterostructure photodetector that contains 1D Te and 2D WS 2 . In this device, 1D Te induces in-plane strain in 2D WS 2 , which regulates the electronic structures of local WS 2 and gives rise to type-II band alignment in the horizontal direction. Moreover, the vertical heterojunction built of 2D WS 2 and 1D Te introduces a high photoconductive gain. Benefiting from these two effects, the transfer of photogenerated carriers is optimized, and the proposed photodetector exhibits high sensitivity (photoresponsivity of ~27.7 A W −1 , detectivity of 9.5 × 10 12 Jones, and short rise/ decay time of 19.3/17.6 ms). In addition, anisotropic photodetection characteristics with a dichroic ratio up to 2.1 are achieved. This hybrid 1D/2D heterostructure overcomes the inherent limitations of each material and realizes novel properties, opening up a new avenue towards constructing multifunctional optoelectronic devices.

Rational Design of WSe2/WS2/WSe2 Dual Junction Phototransistor Incorporating High Responsivity and Detectivity

“…[ 25,26 ] The main Raman peaks in F‐WS 2 are at 348 and 414 cm −1 , belonging to E 1 2g and A 1g modes, respectively. [ 27 ] Notably, the Raman peaks in the overlapped regions are consistent with the individual ones, indicating that high‐quality vdW heterostructures are obtained after the transfer processes. [ 14 ] The PL spectra from different areas are also recorded and presented in Figure 2f and Figure S6 (Supporting Information).…”

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

“…Generally, R decreases as a function of P laser , and some fluctuations arise from the formation of defects and charged impurities and the recombination processes of electron–hole pairs. [ 45–47 ] For the Photodetector No.1 with bottom patterns, R can reach 10.0 A W −1 , comparable to the best performance of conventional WSe 2 /ReS 2 heterostructures. [ 13 ] For the Photodetector No.2, the maximum R of unpatterned and patterned heterojunction is 0.29 and 0.13 A W −1 , respectively.…”

Integration of photovoltaic and photogating effects in a WSe2/WS2/p-Si dual junction photodetector featuring high-sensitivity and fast-response

“…The typical Raman peaks obtained for WS 2 and WSe 2 are in agreement with previously reported values. [25][26][27] Moreover, the Raman spectra of WSe 2 /WS 2 /p-Si is the sum of WSe 2 and WS 2 , indicating that high quality vdW heterostructures are constructed aer transfer processes. 16 In addition, the Raman peaks of WS 2 in the overlapping region are signicantly quenched, which can be attributed to the interfacial coupling effect and the absorption of excitation light by top WSe 2 .…”