Cu_2NiSnS_4 nanoparticles were prepared for the first time using a facile solid-phase process at a temperature of 180 °C. The crystalline structure, morphology and optical properties of the Cu_2NiSnS_4 nanopartic...Cu_2NiSnS_4 nanoparticles were prepared for the first time using a facile solid-phase process at a temperature of 180 °C. The crystalline structure, morphology and optical properties of the Cu_2NiSnS_4 nanoparticles were characterized by means of X-ray diffraction(XRD), field emission scanning electron microscopy(FESEM), transmission electron microscope(TEM) and ultraviolet-visible(UV-vis) spectrophotometer. The band gap and conversion efficiency of Cu_2NiSnS_4 nanoparticles were studied at various temperature. The results showed that the Cu_2NiSnS_4 nanoparticles exhibited an optimum band gap of 1.58 e V and a conversion efficiency of 0.64% at 180 °C, indicating that it maybe be useful in low-cost thin film solar cells.展开更多
Flash memories and semiconductor p-n junctions are two elementary but incompatible building blocks of most electronic and optoelectronic devices.The pressing demand to efficiently transfer massive data between memorie...Flash memories and semiconductor p-n junctions are two elementary but incompatible building blocks of most electronic and optoelectronic devices.The pressing demand to efficiently transfer massive data between memories and logic circuits,as well as for high data storage capability and device integration density,has fueled the rapid growth of technique and material innovations.Two-dimensional(2D)materials are considered as one of the most promising candidates to solve this challenge.However,a key aspect for 2D materials to build functional devices requires effective and accurate control of the carrier polarity,concentration and spatial distribution in the atomically thin structures.Here,a non-volatile opto-electrical doping approach is demonstrated,which enables reversibly writing spatially resolved doping patterns in the MoTe2 conductance channel through a MoTe2/hexagonal boron nitride(h-BN)heterostructure.Based on the doping effect induced by the combination of electrostatic modulation and ultraviolet light illumination,a 3-bit flash memory and various homojunctions on the same MoTe2/BN heterostructure are successfully developed.The flash memory achieved 8 well distinguished memory states with a maximum on/off ratio over 10^4.Each state showed negligible decay during the retention time of 2,400 s.The heterostructure also allowed the formation of p-p,n-n,p-n,and n-p homojunctions and the free transition among these states.The MoTe2 p-n homojunction with a rectification ratio of 10^3 exhibited excellent photodetection and photovoltaic performance.Having the memory device and p-n junction built on the same structure makes it possible to bring memory and computational circuit on the same chip,one step further to realize near-memory computing.展开更多
基金supported by the Fundamental Research Funds for the Central Public Welfare Research Institutes (No.TKS20200311)。
文摘Cu_2NiSnS_4 nanoparticles were prepared for the first time using a facile solid-phase process at a temperature of 180 °C. The crystalline structure, morphology and optical properties of the Cu_2NiSnS_4 nanoparticles were characterized by means of X-ray diffraction(XRD), field emission scanning electron microscopy(FESEM), transmission electron microscope(TEM) and ultraviolet-visible(UV-vis) spectrophotometer. The band gap and conversion efficiency of Cu_2NiSnS_4 nanoparticles were studied at various temperature. The results showed that the Cu_2NiSnS_4 nanoparticles exhibited an optimum band gap of 1.58 e V and a conversion efficiency of 0.64% at 180 °C, indicating that it maybe be useful in low-cost thin film solar cells.
基金supported by the National Natural Science Foundation of China (51902098, 51972105, 51525202, and 61574054)the Hunan Provincial Natural Science Foundation (2018RS3051).
基金This work is supported by the National Natural Science Foundation of China(No.21405109)Seed Foundation of State Key Laboratory of Precision Measurement Technology and Instruments,China(No.Pilt1710).
文摘Flash memories and semiconductor p-n junctions are two elementary but incompatible building blocks of most electronic and optoelectronic devices.The pressing demand to efficiently transfer massive data between memories and logic circuits,as well as for high data storage capability and device integration density,has fueled the rapid growth of technique and material innovations.Two-dimensional(2D)materials are considered as one of the most promising candidates to solve this challenge.However,a key aspect for 2D materials to build functional devices requires effective and accurate control of the carrier polarity,concentration and spatial distribution in the atomically thin structures.Here,a non-volatile opto-electrical doping approach is demonstrated,which enables reversibly writing spatially resolved doping patterns in the MoTe2 conductance channel through a MoTe2/hexagonal boron nitride(h-BN)heterostructure.Based on the doping effect induced by the combination of electrostatic modulation and ultraviolet light illumination,a 3-bit flash memory and various homojunctions on the same MoTe2/BN heterostructure are successfully developed.The flash memory achieved 8 well distinguished memory states with a maximum on/off ratio over 10^4.Each state showed negligible decay during the retention time of 2,400 s.The heterostructure also allowed the formation of p-p,n-n,p-n,and n-p homojunctions and the free transition among these states.The MoTe2 p-n homojunction with a rectification ratio of 10^3 exhibited excellent photodetection and photovoltaic performance.Having the memory device and p-n junction built on the same structure makes it possible to bring memory and computational circuit on the same chip,one step further to realize near-memory computing.
