Van der Waals(vdW)heterostructures based on two-dimensional transitionmetal dichalcogenides have provided unprecedented opportunities for photovoltaic detectors owing to their strong light-matter interaction and ultra...Van der Waals(vdW)heterostructures based on two-dimensional transitionmetal dichalcogenides have provided unprecedented opportunities for photovoltaic detectors owing to their strong light-matter interaction and ultrafast interfacial charge transfer.Despite continued advancement,insufficient control of photocarrier behaviors still limits the external quantum efficiency(EQE)and operation speed of such detectors.Here,we propose a synergistic strategy of contact-configuration design and thickness-modulation to construct high-performance vdW photodiodes based on the typical type II heterostructure(MoS2/WSe2).Through integrating three contact architectures into one device to exclude other factors,we solid the superiority of designed 1L-MoS2/WSe2/graphene heterostructures incorporating efficient photocarrier collection and gate modulation.Together with leveraging the layer-numberdependent properties of WSe2,we observe the critical thickness of WSe2(11 layers)for the highest EQE,which verifies the thickness-dependent competition between photocarrier generation,dissociation,and collection.Finally,we demonstrate the synergistic-engineered vdW heterostructure can trigger record-high EQE(61%)and manifest ultrafast photoresponse(4.1μs)at the atomically thin limit(8 nm).The proposed strategy enables architecture-design and thickness-engineering to unlock the potential to realize high-performance optoelectronic devices.展开更多
基金National Natural Science Foundation of China,Grant/Award Numbers:51672026,51972022,51991340,51991342,92163205the Fundamental Research Funds for the Central Universities,Grant/Award Number:FRF-TP-19-025A3+2 种基金the National Key Research and Development Program of China,Grant/Award Number:2018YFA0703503the Natural Science Foundation of Beijing Municipality,Grant/Award Number:Z180011the Overseas Expertise Introduction Projects for Discipline Innovation,Grant/Award Number:B14003。
文摘Van der Waals(vdW)heterostructures based on two-dimensional transitionmetal dichalcogenides have provided unprecedented opportunities for photovoltaic detectors owing to their strong light-matter interaction and ultrafast interfacial charge transfer.Despite continued advancement,insufficient control of photocarrier behaviors still limits the external quantum efficiency(EQE)and operation speed of such detectors.Here,we propose a synergistic strategy of contact-configuration design and thickness-modulation to construct high-performance vdW photodiodes based on the typical type II heterostructure(MoS2/WSe2).Through integrating three contact architectures into one device to exclude other factors,we solid the superiority of designed 1L-MoS2/WSe2/graphene heterostructures incorporating efficient photocarrier collection and gate modulation.Together with leveraging the layer-numberdependent properties of WSe2,we observe the critical thickness of WSe2(11 layers)for the highest EQE,which verifies the thickness-dependent competition between photocarrier generation,dissociation,and collection.Finally,we demonstrate the synergistic-engineered vdW heterostructure can trigger record-high EQE(61%)and manifest ultrafast photoresponse(4.1μs)at the atomically thin limit(8 nm).The proposed strategy enables architecture-design and thickness-engineering to unlock the potential to realize high-performance optoelectronic devices.
