The parent compounds of the high-temperature cuprate superconductors are Mott insulators.It has been generally agreed that understanding the physics of the doped Mott insulators is essential to understanding the mecha...The parent compounds of the high-temperature cuprate superconductors are Mott insulators.It has been generally agreed that understanding the physics of the doped Mott insulators is essential to understanding the mechanism of high temperature superconductivity.A natural starting point is to elucidate the basic electronic structure of the parent compound.Here we report comprehensive high resolution angle-resolved photoemission measurements on Ca_2CuO_2Cl_2,a Mott insulator and a prototypical parent compound of the cuprates.Multiple underl.ying Fermi surface sheets are revealed for the first time.The high energy waterfall-like band dispersions exhibit different behaviors near the nodal and antinodal regions.Two distinct energy scales are identified：a d-wave-like low energy peak dispersion and a nearly isotropic lower Hubbard band gap.These observations provide new information of the electronic structure of the cuprate parent compound,which is important for understanding the anomalous physical properties and superconductivity mechanism of the high temperature cuprate superconductors.展开更多
An efficient room-temperature self-powered,broadband(300 nm–1100 nm)photodetector based on a CuO–TiO_(2)/TiO_(2)/p-Si(100)heterostructure is demonstrated.The CuO–TiO_(2)nanocomposites were grown in a two-zone horiz...An efficient room-temperature self-powered,broadband(300 nm–1100 nm)photodetector based on a CuO–TiO_(2)/TiO_(2)/p-Si(100)heterostructure is demonstrated.The CuO–TiO_(2)nanocomposites were grown in a two-zone horizontal tube furnace on a 40 nm TiO_(2)thin film deposited on a p-type Si(100)substrate.The CuO–TiO_(2)/TiO_(2)/p-Si(100)devices exhibited excellent rectification characteristics under dark and individual photoillumination conditions.The devices showed remarkable photo-response under broadband(300–1100 nm)light illumination at zero bias voltage,indicating the achievement of highly sensitive self-powered photodetectors at visible and near-infrared light illuminations.The maximum response of the devices is observed at 300 nm for an illumination power of 10 W.The response and recovery times were calculated as 86 ms and 78 ms,respectively.Moreover,under a small bias,the devices showed a prompt binary response by altering the current from positive to negative under illumination conditions.The main reason behind this binary response is the low turn-on voltage and photovoltaic characteristics of the devices.Under illumination conditions,the generation of photocurrent is due to the separation of photogenerated electron-hole pairs within the built-in electric field at the CuO–TiO_(2)/TiO_(2)interface.These characteristics make the CuO–TiO_(2)/TiO_(2)broadband photodetectors suitable for applications that require high response speeds and self-sufficient functionality.展开更多
A series of MoS_(2)-modified CuO(CuO/MoS_(2))heterostructures were successfully fabricated.The photodegradation properties of organic dyes were explored in detail under visible light.The photocatalytic results demonst...A series of MoS_(2)-modified CuO(CuO/MoS_(2))heterostructures were successfully fabricated.The photodegradation properties of organic dyes were explored in detail under visible light.The photocatalytic results demonstrate that the CuO/MoS_(2)-3 heterostructure delivers superior degradation rates towards methyl violet dye(MV)and rhodamine B(RhB),reaching 99.8%and 95.3%within 30 min,respectively.The decent photodegradation activity is due to improved visible light adsorption and faster transfer of electron-hole pairs.The radical trapping experiments show that superoxide radicals(O_(2)^(-))and holes(h+)are the main active species in the removal of MV.Furthermore,the CuO/MoS_(2)-3 composite possesses the prominent stability and recyclability.This work offers a highly sustainable technique for designing a high-efficiency photocatalyst to remove environmental pollutants.展开更多
Nanocrystalline SnO<sub>2</sub> and CuO doped with SnO<sub>2</sub> were prepared by the co-precipitation method and characterized for different physiochemical properties and microbiological act...Nanocrystalline SnO<sub>2</sub> and CuO doped with SnO<sub>2</sub> were prepared by the co-precipitation method and characterized for different physiochemical properties and microbiological activity. The composition and morphological formation were characterized by XRD, HRTEM, Raman, FTIR, and UV-vis spectroscopy. The Powder X-ray analysis reveals that Sn4+ ions have substituted the Cu<sup>2+</sup> ions without changing the monoclinic structure of SnO<sub>2</sub> but the average particle size of the SnO<sub>2</sub> and CuO doped SnO<sub>2</sub> samples from 11 and 5 nm respectively. However, it exhibits an inhibiting strong bacterial growth against tested bacterial strains.展开更多
基金Supported by the National Key Research and Development Program of China(2016YFA0300300)the National Natural Science Foundation of China(11334010 and 11534007)+1 种基金the National Basic Research Program of China(2015CB921000)the Strategic Priority Research Program(B)of Chinese Academy of Sciences(XDB07020300)
文摘The parent compounds of the high-temperature cuprate superconductors are Mott insulators.It has been generally agreed that understanding the physics of the doped Mott insulators is essential to understanding the mechanism of high temperature superconductivity.A natural starting point is to elucidate the basic electronic structure of the parent compound.Here we report comprehensive high resolution angle-resolved photoemission measurements on Ca_2CuO_2Cl_2,a Mott insulator and a prototypical parent compound of the cuprates.Multiple underl.ying Fermi surface sheets are revealed for the first time.The high energy waterfall-like band dispersions exhibit different behaviors near the nodal and antinodal regions.Two distinct energy scales are identified：a d-wave-like low energy peak dispersion and a nearly isotropic lower Hubbard band gap.These observations provide new information of the electronic structure of the cuprate parent compound,which is important for understanding the anomalous physical properties and superconductivity mechanism of the high temperature cuprate superconductors.
基金CSIR-09/0973(11599)/2021-EMR-I and SERB(Project no:CRG/2021/000255),Department of Science and Technology,Govt.of India。
文摘An efficient room-temperature self-powered,broadband(300 nm–1100 nm)photodetector based on a CuO–TiO_(2)/TiO_(2)/p-Si(100)heterostructure is demonstrated.The CuO–TiO_(2)nanocomposites were grown in a two-zone horizontal tube furnace on a 40 nm TiO_(2)thin film deposited on a p-type Si(100)substrate.The CuO–TiO_(2)/TiO_(2)/p-Si(100)devices exhibited excellent rectification characteristics under dark and individual photoillumination conditions.The devices showed remarkable photo-response under broadband(300–1100 nm)light illumination at zero bias voltage,indicating the achievement of highly sensitive self-powered photodetectors at visible and near-infrared light illuminations.The maximum response of the devices is observed at 300 nm for an illumination power of 10 W.The response and recovery times were calculated as 86 ms and 78 ms,respectively.Moreover,under a small bias,the devices showed a prompt binary response by altering the current from positive to negative under illumination conditions.The main reason behind this binary response is the low turn-on voltage and photovoltaic characteristics of the devices.Under illumination conditions,the generation of photocurrent is due to the separation of photogenerated electron-hole pairs within the built-in electric field at the CuO–TiO_(2)/TiO_(2)interface.These characteristics make the CuO–TiO_(2)/TiO_(2)broadband photodetectors suitable for applications that require high response speeds and self-sufficient functionality.
基金the National Natural Science Foundation of China(51572185)Natural Science Foundation of Shanxi Province(202203021211158 and 20210302123173)the Key Research and Developmen program of Shanxi Province(International Cooperation,201903D421079)for the financial support.
文摘A series of MoS_(2)-modified CuO(CuO/MoS_(2))heterostructures were successfully fabricated.The photodegradation properties of organic dyes were explored in detail under visible light.The photocatalytic results demonstrate that the CuO/MoS_(2)-3 heterostructure delivers superior degradation rates towards methyl violet dye(MV)and rhodamine B(RhB),reaching 99.8%and 95.3%within 30 min,respectively.The decent photodegradation activity is due to improved visible light adsorption and faster transfer of electron-hole pairs.The radical trapping experiments show that superoxide radicals(O_(2)^(-))and holes(h+)are the main active species in the removal of MV.Furthermore,the CuO/MoS_(2)-3 composite possesses the prominent stability and recyclability.This work offers a highly sustainable technique for designing a high-efficiency photocatalyst to remove environmental pollutants.
文摘Nanocrystalline SnO<sub>2</sub> and CuO doped with SnO<sub>2</sub> were prepared by the co-precipitation method and characterized for different physiochemical properties and microbiological activity. The composition and morphological formation were characterized by XRD, HRTEM, Raman, FTIR, and UV-vis spectroscopy. The Powder X-ray analysis reveals that Sn4+ ions have substituted the Cu<sup>2+</sup> ions without changing the monoclinic structure of SnO<sub>2</sub> but the average particle size of the SnO<sub>2</sub> and CuO doped SnO<sub>2</sub> samples from 11 and 5 nm respectively. However, it exhibits an inhibiting strong bacterial growth against tested bacterial strains.
