Gradient heterostructure is one of fundamental interfaces and provides an effective platform to achieve gradually changed properties in mechanics,optics,and electronics.Among different types of heterostructures,the gr...Gradient heterostructure is one of fundamental interfaces and provides an effective platform to achieve gradually changed properties in mechanics,optics,and electronics.Among different types of heterostructures,the gradient one may provide multiple resistive states and immobilized conductive fila-ments,offering great prospect for fabricating memristors with both high neuromorphic computation capability and repeatability.Here,we invent a memristor based on a homologous gradient heterostructure(HGHS),compris-ing a conductive transition metal dichalcogenide and an insulating homolo-gous metal oxide.Memristor made of Ta–TaS_(x)O_(y)–TaS 2 HGHS exhibits continuous potentiation/depression behavior and repeatable forward/backward scanning in the read-voltage range,which are dominated by multi-ple resistive states and immobilized conductive filaments in HGHS,respec-tively.Moreover,the continuous potentiation/depression behavior makes the memristor serve as a synapse,featuring broad-frequency response(10^(-1)–10^(5) Hz,covering 106 frequency range)and multiple-mode learning(enhanced,depressed,and random-level modes)based on its natural and moti-vated forgetting behaviors.Such HGHS-based memristor also shows good unifor-mity for 5?7 device arrays.Our work paves a way to achieve high-performance integrated memristors for future artificial neuromorphic computation.展开更多
A high-performance heterojunction photodetector is formed by combining an n-type Si substrate with p-type monolayer WSe2 obtained using physical vapor deposition. The high quality of the WSe2/Si heterojunction is demo...A high-performance heterojunction photodetector is formed by combining an n-type Si substrate with p-type monolayer WSe2 obtained using physical vapor deposition. The high quality of the WSe2/Si heterojunction is demonstrated by the suppressed dark current of I nA and the extremely high rectification ratio of 107. Under illumination, the heterojunction exhibits a wide photoresponse range from ultraviolet to near-infrared radiation. The introduction of graphene quantum dots （GQDs） greatly elevates the photodetective capabilities of the heterojunction with strong light absorption and long carrier lifetimes. The GQDs/WSe2/Si heterojunction exhibits a high responsivity of -707 mA·W^-1, short response time of 0.2 ms, and good specific detectivity of -4.51×10^9 Jones. These properties suggest that the GQDs/WSe2/Si heterojunction holds great potential for application in future high- performance photodetectors.展开更多
The controllable growth of two-dimensional(2D)semiconductors with large domain sizes and high quality is much needed in order to reduce the detrimental efect of grain boundaries on device performance but has proven to...The controllable growth of two-dimensional(2D)semiconductors with large domain sizes and high quality is much needed in order to reduce the detrimental efect of grain boundaries on device performance but has proven to be challenging.Here,we analyze the precursor concentration on the substrate surface which signifcantly infuences nucleation density in a vapor deposition growth process and design a confned micro-reactor to grow 2D In_(2)Se_(3) with large domain sizes and high quality.Te uniqueness of this confned micro-reactor is that its size is∼102-103 times smaller than that of a conventional reactor.Such a remarkably small reactor causes a very low precursor concentration on the substrate surface,which reduces nucleation density and leads to the growth of 2D In_(2)Se_(3) grains with sizes larger than 200�m.Our experimental results show large domain sizes of the 2D In_(2)Se_(3) with high crystallinity.Te fexible broadband photodetectors based on the as-grown In_(2)Se_(3) show rise and decay times of 140 ms and 25 ms,efcient response(5.6 A/W),excellent detectivity(7×10^(10) Jones),high external quantum efciency(251%),good fexibility,and high stability.Tis study,in principle,provides an efective strategy for the controllable growth of high quality 2D materials with few grain boundaries.展开更多
基金We thank the financial support from the National Science Fund for Distinguished Young Scholars(No.52125309)the National Natural Science Foundation of China(Nos.51991343,52188101,51920105002,and 51991340)+1 种基金Guang-dong Innovative and Entrepreneurial Research Team Pro-gram(No.2017ZT07C341)the Shenzhen Basic Research Program(Nos.JCYJ20200109144616617 and JCYJ20200109144620815)。
文摘Gradient heterostructure is one of fundamental interfaces and provides an effective platform to achieve gradually changed properties in mechanics,optics,and electronics.Among different types of heterostructures,the gradient one may provide multiple resistive states and immobilized conductive fila-ments,offering great prospect for fabricating memristors with both high neuromorphic computation capability and repeatability.Here,we invent a memristor based on a homologous gradient heterostructure(HGHS),compris-ing a conductive transition metal dichalcogenide and an insulating homolo-gous metal oxide.Memristor made of Ta–TaS_(x)O_(y)–TaS 2 HGHS exhibits continuous potentiation/depression behavior and repeatable forward/backward scanning in the read-voltage range,which are dominated by multi-ple resistive states and immobilized conductive filaments in HGHS,respec-tively.Moreover,the continuous potentiation/depression behavior makes the memristor serve as a synapse,featuring broad-frequency response(10^(-1)–10^(5) Hz,covering 106 frequency range)and multiple-mode learning(enhanced,depressed,and random-level modes)based on its natural and moti-vated forgetting behaviors.Such HGHS-based memristor also shows good unifor-mity for 5?7 device arrays.Our work paves a way to achieve high-performance integrated memristors for future artificial neuromorphic computation.
文摘A high-performance heterojunction photodetector is formed by combining an n-type Si substrate with p-type monolayer WSe2 obtained using physical vapor deposition. The high quality of the WSe2/Si heterojunction is demonstrated by the suppressed dark current of I nA and the extremely high rectification ratio of 107. Under illumination, the heterojunction exhibits a wide photoresponse range from ultraviolet to near-infrared radiation. The introduction of graphene quantum dots （GQDs） greatly elevates the photodetective capabilities of the heterojunction with strong light absorption and long carrier lifetimes. The GQDs/WSe2/Si heterojunction exhibits a high responsivity of -707 mA·W^-1, short response time of 0.2 ms, and good specific detectivity of -4.51×10^9 Jones. These properties suggest that the GQDs/WSe2/Si heterojunction holds great potential for application in future high- performance photodetectors.
基金support from the National Natural Science Foundation of China (51722206 and 11674150)the Youth 1000-Talent Program of China+3 种基金the Economic, Trade and Information Commission of Shenzhen Municipality for the “2017 Graphene Manufacturing Innovation Center Project” (201901171523)Shenzhen Basic Research Project (JCYJ20170307140956657 and JCYJ20160613160524999)Guangdong Innovative and Entrepreneurial Research Team Program (2017ZT07C341 and 2016ZT06D348)the Development and Reform Commission of Shenzhen Municipality for the development of the “Low-Dimensional Materials and Devices” discipline
基金This work was supported by the National Natural Science Foundation of China(51920105002,51991340,51722206,and 51991343)Guangdong Innovative and Entrepreneurial Research Team Program(2017ZT07C341)+1 种基金the Bureau of Industry and Information Technology of Shenzhen for the“2017 Graphene Manufacturing Innovation Center Project”(201901171523)the Shenzhen Basic Research Program(JCYJ20200109144620815 and JCYJ20200109144616617).
基金This work was fnancially supported by the National Natural Science Foundation of China(Nos.51521091 and 51722206)the Youth 1000-Talent Program of China,the National Key R&D Program(2018YFA0307200)+3 种基金the Shenzhen Basic Research Project(Nos.JCYJ20170307140956657,JCYJ20160613160524999,JCYJ20170412152620376,and ZDSYS20170303165926217)Trade and Information Commission of Shenzhen Municipality for the“2017 Graphene Manufacturing Innovation Center Project”(No.201901171523)Guangdong Innovative and Entrepreneurial Research Team Program(Grant No.2017ZT07C341)the Development and Reform Commission of Shenzhen Municipality for the development of the“Low-Dimensional Materials and Devices”discipline.
文摘The controllable growth of two-dimensional(2D)semiconductors with large domain sizes and high quality is much needed in order to reduce the detrimental efect of grain boundaries on device performance but has proven to be challenging.Here,we analyze the precursor concentration on the substrate surface which signifcantly infuences nucleation density in a vapor deposition growth process and design a confned micro-reactor to grow 2D In_(2)Se_(3) with large domain sizes and high quality.Te uniqueness of this confned micro-reactor is that its size is∼102-103 times smaller than that of a conventional reactor.Such a remarkably small reactor causes a very low precursor concentration on the substrate surface,which reduces nucleation density and leads to the growth of 2D In_(2)Se_(3) grains with sizes larger than 200�m.Our experimental results show large domain sizes of the 2D In_(2)Se_(3) with high crystallinity.Te fexible broadband photodetectors based on the as-grown In_(2)Se_(3) show rise and decay times of 140 ms and 25 ms,efcient response(5.6 A/W),excellent detectivity(7×10^(10) Jones),high external quantum efciency(251%),good fexibility,and high stability.Tis study,in principle,provides an efective strategy for the controllable growth of high quality 2D materials with few grain boundaries.
