本文叙述了盖得的发明专利,从初期的汞扩散泵到分馏油扩散泵的演变过程。讨论了泵体结构、喷咀型式、泵油性能和几个关键技术问题。现代油扩散泵的何氏系数达0.65以上,返油率达10-5 mg/cm2.min,1 kW功率抽气量可达200 Pa L/s。最后对泵...本文叙述了盖得的发明专利,从初期的汞扩散泵到分馏油扩散泵的演变过程。讨论了泵体结构、喷咀型式、泵油性能和几个关键技术问题。现代油扩散泵的何氏系数达0.65以上,返油率达10-5 mg/cm2.min,1 kW功率抽气量可达200 Pa L/s。最后对泵的性能、结构和应用前景作了展望。展开更多
Artificial van der Waals(vdWs)heterostructures offer unprecedented opportunities to explore and reveal novel synergistic electronic and optical phenomena,which are beneficial for the development of novel optoelectroni...Artificial van der Waals(vdWs)heterostructures offer unprecedented opportunities to explore and reveal novel synergistic electronic and optical phenomena,which are beneficial for the development of novel optoelectronic devices at atomic limits.However,due to the damage caused by the device fabrication process,their inherent properties such as carrier mobility are obscured,which hinders the improvement of device performance and the incorporation of vdWs materials into next-generation integrated circuits.Herein,combining pump-probe spectroscopic and scanning probe microscopic techniques,the intrinsic optoelectronic properties of PtSe_(2)/MoSe_(2)heterojunction were nondestructively and systematically investigated.The heterojunction exhibits a broad-spectrum optical response and maintains ultrafast carrier dynamics(interfacial charge transfer~0.8 ps and carrier lifetime~38.2 ps)simultaneously.The in-plane exciton diffusion coefficient of the heterojunction was extracted(19.4±7.6 cm^(2)∙s^(−1)),and its exciton mobility as high as 756.8 cm^(2)∙V−1∙s^(−1)was deduced,exceeding the value of its components.This enhancement was attributed to the formation of an n-type Schottky junction between PtSe_(2)and MoSe_(2),and its built-in electric field assisted the ultrafast transfer of photogenerated carriers from MoSe_(2)to PtSe_(2),enhancing the in-plane exciton diffusion of the heterojunction.Our results demonstrate that PtSe_(2)/MoSe_(2)is suitable for the development of broadspectrum and sensitive optoelectronic devices.Meanwhile,the results contribute to a fundamental understanding of the performance of various optoelectronic devices based on such PtSe_(2)two-dimensional(2D)heterostructures.展开更多
基金supported by the National Natural Science Foundation of China(Nos.11974088,61975007,52172060,61925401,92064004,61927901,and 92164302)the Beijing Natural Science Foundation(Nos.Z190006 and 4222073)+1 种基金the National Key R&D Program of China(No.2018YFA0208402),the 111 Project(No.B18001)the Fok Ying-Tong Education Foundation,and the Tencent Foundation through the XPLORER PRIZE。
文摘Artificial van der Waals(vdWs)heterostructures offer unprecedented opportunities to explore and reveal novel synergistic electronic and optical phenomena,which are beneficial for the development of novel optoelectronic devices at atomic limits.However,due to the damage caused by the device fabrication process,their inherent properties such as carrier mobility are obscured,which hinders the improvement of device performance and the incorporation of vdWs materials into next-generation integrated circuits.Herein,combining pump-probe spectroscopic and scanning probe microscopic techniques,the intrinsic optoelectronic properties of PtSe_(2)/MoSe_(2)heterojunction were nondestructively and systematically investigated.The heterojunction exhibits a broad-spectrum optical response and maintains ultrafast carrier dynamics(interfacial charge transfer~0.8 ps and carrier lifetime~38.2 ps)simultaneously.The in-plane exciton diffusion coefficient of the heterojunction was extracted(19.4±7.6 cm^(2)∙s^(−1)),and its exciton mobility as high as 756.8 cm^(2)∙V−1∙s^(−1)was deduced,exceeding the value of its components.This enhancement was attributed to the formation of an n-type Schottky junction between PtSe_(2)and MoSe_(2),and its built-in electric field assisted the ultrafast transfer of photogenerated carriers from MoSe_(2)to PtSe_(2),enhancing the in-plane exciton diffusion of the heterojunction.Our results demonstrate that PtSe_(2)/MoSe_(2)is suitable for the development of broadspectrum and sensitive optoelectronic devices.Meanwhile,the results contribute to a fundamental understanding of the performance of various optoelectronic devices based on such PtSe_(2)two-dimensional(2D)heterostructures.
