Monolayer transition-metal dichalcogenides （TMDs） are considered to be fantastic building blocks for a wide variety of optical and optoelectronic devices such as sensors, photodetectors, and quantum emitters, owing ...Monolayer transition-metal dichalcogenides （TMDs） are considered to be fantastic building blocks for a wide variety of optical and optoelectronic devices such as sensors, photodetectors, and quantum emitters, owing to their direct band gap, transparency, and mechanical flexibility. The core element of many conventional electronic and optoelectronic devices is the p-n junction, in which the p- and n-types of the semiconductor are formed by chemical doping in different regions. Here, we report a series of optoelectronic studies on a monolayer WSe2 in-plane p-n photodetector, demonstrating a low- power dissipation by showing an ambipolar behavior with a reduced threshold voltage by a factor of two compared with the previous results on a lateral electrostatically doped WSe2 p-n junction. The fabrication of the device is based on a polycarbonates （PC） transfer technique and hence no electron-beam exposure induced damage to the monolayer WSe2 is expected. Upon optical excitation, the photodetector demonstrates a photoresponsivity of 0.12 mA.W-1 and a maximum external quantum efficiency of 0.03%. Our study provides an alternative platform for a flexible and transparent two- dimensional photodetector, from which we expect to further promote the development of next-generation optoelectronic devices.展开更多
Monolayer transition-metal dichalcogenides（TMDs） have attracted a lot of attention for their applications in optics and optoelectronics.Molybdenum disulfide（MoS2）,as one of those important materials,has been widel...Monolayer transition-metal dichalcogenides（TMDs） have attracted a lot of attention for their applications in optics and optoelectronics.Molybdenum disulfide（MoS2）,as one of those important materials,has been widely investigated due to its direct band gap and photoluminescence（PL） in visible range.Owing to the fact that the monolayer MoS2 suffers low light absorption and emission,surface plasmon polaritons（SPPs） are used to enhance both the excitation and emission efficiencies.Here,we demonstrate that the PL of MoS2 sandwiched between 200-nm-diameter gold nanoparticle（Au NP） and 150-nm-thick gold film is improved by more than 4 times compared with bare MoS2 sample.This study shows that gap plasmons can possess more optical and optoelectronic applications incorporating with many other emerging two-dimensional materials.展开更多
In photonie integrated circuits, information is usually encoded in the optical path. In this work, based on the multi-mode dielectric-loaded surface plasmon polariton waveguide, we numerically design a directional cou...In photonie integrated circuits, information is usually encoded in the optical path. In this work, based on the multi-mode dielectric-loaded surface plasmon polariton waveguide, we numerically design a directional coupler, which can divide the different waveguide eigenmodes into different optical paths. The results show a possibility to encode information onto different waveguide modes. We also experimentally demonstrate that the splitting ratio of this directional coupler structure can be tuned without changing its size.展开更多
Monolayer transition metal dichalcogenides(TMDs) are widely used for integrated optical and photoelectric devices.Owing to their broken inversion symmetry, monolayer TMDs have a large second-order optical nonlinearity...Monolayer transition metal dichalcogenides(TMDs) are widely used for integrated optical and photoelectric devices.Owing to their broken inversion symmetry, monolayer TMDs have a large second-order optical nonlinearity. However, the optical second-order nonlinear conversion efficiency of monolayer TMDs is still limited by the interaction length. In this work, we theoretically study the second harmonic generation(SHG) from monolayer tungsten sulfide(WS2) enhanced by a silica microsphere cavity. By tuning the position, size, and crystal orientation of the material, second-order nonlinear coupling can occur between the fundamental pump mode and different second harmonic cavity modes, and we obtain an optimal SHG conversion efficiency with orders of magnitude enhancement. Our work demonstrates that the microsphere cavity can significantly enhance SHG from monolayer 2D materials under flexible conditions.展开更多
Based on the one-dimensional periodic and Fibonacci-like waveguide arrays,we experimentally investigate localized quantum walks(QWs),both in the linear and nonlinear regimes.Unlike the ballistic transport behavior in ...Based on the one-dimensional periodic and Fibonacci-like waveguide arrays,we experimentally investigate localized quantum walks(QWs),both in the linear and nonlinear regimes.Unlike the ballistic transport behavior in conventional random QWs,localization of QWs is obtained in the Fibonacci-like waveguide arrays both theoretically and experimentally.Moreover,we verify the enhancement of the localization through nonlinearity-induced effect.Our work provides a valid way to study localization enhancement in QWs,which might broaden the understanding of nonlinearity-induced behaviors in quasiperiodic systems.展开更多
基金Supported by the National Key Basic Research and Development Programme of China under Grant No 2001CB309300, the National Natural Science Foundation of China under Grant No 10304017, the Knowledge Innovation Funds of Chinese Academy of Sciences.
基金Supported by the National Natural Science Foundation of China under Grant Nos 50703038, 50773075 and 50533040, the Knowledge Innovation Project of Chinese Academy of Sciences （KJCX3.SYW.H02 and KJCX2-YW-M11）, China Postdoctoral Science Foundation （No 20100470038）, and the National Basic Research Program of China under Grant No 2006cb302900.
基金Supported by the National Basic Research Programme of China under Grant No 2006CB921900, the National Natural Science Foundation of China under Grant No 10604052, the Programme for New Century Excellent Talents in University, the Knowledge Innovation Project of Chinese Academy of Sciences under Gait No KGCX2-YW-103, the Programme of the Education Department of Anhui Province under Grant No 2006kj074A, the China Postdoctoral Science Foundation of China under Grant No 20060400205, the K. C. Wong Education Foundation of Hong Kong.
基金Project supported by the National Key Research and Development Program of China(Grant No.2016YFA0301700)the National Natural Science Foundation of China(Grant Nos.61590932,11774333,61674132,11674300,11575172,and 11625419)+2 种基金the Anhui Provincial Initiative in Quantum Information Technologies,China(Grant Nos.AHY080000 and AHY130300)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB24030601)the Fundamental Research Funds for the Central Universities,China
文摘Monolayer transition-metal dichalcogenides （TMDs） are considered to be fantastic building blocks for a wide variety of optical and optoelectronic devices such as sensors, photodetectors, and quantum emitters, owing to their direct band gap, transparency, and mechanical flexibility. The core element of many conventional electronic and optoelectronic devices is the p-n junction, in which the p- and n-types of the semiconductor are formed by chemical doping in different regions. Here, we report a series of optoelectronic studies on a monolayer WSe2 in-plane p-n photodetector, demonstrating a low- power dissipation by showing an ambipolar behavior with a reduced threshold voltage by a factor of two compared with the previous results on a lateral electrostatically doped WSe2 p-n junction. The fabrication of the device is based on a polycarbonates （PC） transfer technique and hence no electron-beam exposure induced damage to the monolayer WSe2 is expected. Upon optical excitation, the photodetector demonstrates a photoresponsivity of 0.12 mA.W-1 and a maximum external quantum efficiency of 0.03%. Our study provides an alternative platform for a flexible and transparent two- dimensional photodetector, from which we expect to further promote the development of next-generation optoelectronic devices.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61590932 and 11774333)the Anhui Initiative Project in Quantum Information Technologies,China(Grant No.AHY130300)+2 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB24030600)the National Key Research and Development Program of China(Grant No.2016YFA0301700)the Fundamental Research Funds for the Central Universities,China
文摘Monolayer transition-metal dichalcogenides（TMDs） have attracted a lot of attention for their applications in optics and optoelectronics.Molybdenum disulfide（MoS2）,as one of those important materials,has been widely investigated due to its direct band gap and photoluminescence（PL） in visible range.Owing to the fact that the monolayer MoS2 suffers low light absorption and emission,surface plasmon polaritons（SPPs） are used to enhance both the excitation and emission efficiencies.Here,we demonstrate that the PL of MoS2 sandwiched between 200-nm-diameter gold nanoparticle（Au NP） and 150-nm-thick gold film is improved by more than 4 times compared with bare MoS2 sample.This study shows that gap plasmons can possess more optical and optoelectronic applications incorporating with many other emerging two-dimensional materials.
基金Supported by the National Basic Research Program of China under Grant Nos 2011CBA00200 and 2011CB921200the Strategic Priority Research Program(B)of the Chinese Academy of Sciences under Grant No XDB01030200+2 种基金the National Natural Science Foundation of China under Grant No 11374289the Fundamental Research Funds for the Central Universities under Grant No K2470000012the Program for New Century Excellent Talents in University
文摘In photonie integrated circuits, information is usually encoded in the optical path. In this work, based on the multi-mode dielectric-loaded surface plasmon polariton waveguide, we numerically design a directional coupler, which can divide the different waveguide eigenmodes into different optical paths. The results show a possibility to encode information onto different waveguide modes. We also experimentally demonstrate that the splitting ratio of this directional coupler structure can be tuned without changing its size.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 11774333 and 62061160487)the Fundamental Research Funds for the Central Universities。
文摘Monolayer transition metal dichalcogenides(TMDs) are widely used for integrated optical and photoelectric devices.Owing to their broken inversion symmetry, monolayer TMDs have a large second-order optical nonlinearity. However, the optical second-order nonlinear conversion efficiency of monolayer TMDs is still limited by the interaction length. In this work, we theoretically study the second harmonic generation(SHG) from monolayer tungsten sulfide(WS2) enhanced by a silica microsphere cavity. By tuning the position, size, and crystal orientation of the material, second-order nonlinear coupling can occur between the fundamental pump mode and different second harmonic cavity modes, and we obtain an optimal SHG conversion efficiency with orders of magnitude enhancement. Our work demonstrates that the microsphere cavity can significantly enhance SHG from monolayer 2D materials under flexible conditions.
基金supported by the National Natural Science Foundation of China(Nos.61825502,62061160487,and 12204462)the China Postdoctoral Science Foundation(Nos.2022M723061 and 2019M651200)+1 种基金the Major Science and Technology Projects in Jilin Province(No.20220301002GX)the Fundamental Research Funds for the Central Universities.
文摘Based on the one-dimensional periodic and Fibonacci-like waveguide arrays,we experimentally investigate localized quantum walks(QWs),both in the linear and nonlinear regimes.Unlike the ballistic transport behavior in conventional random QWs,localization of QWs is obtained in the Fibonacci-like waveguide arrays both theoretically and experimentally.Moreover,we verify the enhancement of the localization through nonlinearity-induced effect.Our work provides a valid way to study localization enhancement in QWs,which might broaden the understanding of nonlinearity-induced behaviors in quasiperiodic systems.
