Fabrication of atomic dopant wires at large scale is challenging.We explored the feasibility to fabricate atomic dopant wires by nano-patterning self-assembled dopant carrying molecular monolayers via a resist-free li...Fabrication of atomic dopant wires at large scale is challenging.We explored the feasibility to fabricate atomic dopant wires by nano-patterning self-assembled dopant carrying molecular monolayers via a resist-free lithographic approach.The resist-free lithography is to use electron beam exposure to decompose hydrocarbon contaminants in vacuum chamber into amorphous carbon that serves as an etching mask for nanopatterning the phosphorus-bearing monolayers.Dopant wires were fabricated in silicon by patterning diethyl vinylphosphonate monolayers into lines with a width ranging from 1 μm down to 8 nm.The dopants were subsequently driven into silicon to form dopant wires by rapid thermal annealing.Electrical measurements show a linear correlation between wire width and conductance,indicating the success of the monolayer patterning process at nanoscale.The dopant wires can be potentially scaled down to atomic scale if the dopant thermal diffusion can be mitigated.展开更多
The demand for high-performance X-ray detectors leads to material innovationfor efficient photoelectric conversion and carrier transfer. However, currentX-ray detectors are often susceptible to chemical and irradiatio...The demand for high-performance X-ray detectors leads to material innovationfor efficient photoelectric conversion and carrier transfer. However, currentX-ray detectors are often susceptible to chemical and irradiation instability,complex fabrication processes, hazardous components, and difficult compatibility.Here, we investigate a two-dimensional (2D) material with a relativelylow atomic number, Ti_(3)C_(2)T_(x) MXenes, and single crystal silicon for X-ray detectionand single-pixel imaging (SPI). We fabricate a Ti_(3)C_(2)T_(x) MXene/Si X-raydetector demonstrating remarkable optoelectronic performance. This detectorexhibits a sensitivity of 1.2 × 10^(7) μC Gyair^(-1) cm^(-2), a fast response speed with arise time of 31 μs, and an incredibly low detection limit of 2.85 nGyair s^(-1).These superior performances are attributed to the unique charge couplingbehavior under X-ray irradiation via intrinsic polaron formation. The deviceremains stable even after 50 continuous hours of high-dose X-ray irradiation.Our device fabrication process is compatible with silicon-based semiconductortechnology. Our work suggests new directions for eco-friendly X-ray detectorsand low-radiation imaging system.展开更多
Abbe’s resolution limit,one of the best-known physical limitations,poses a great challenge for any wave system in imaging,wave transport,and dynamics.Originally formulated in linear optics,the Abbe limit can be broke...Abbe’s resolution limit,one of the best-known physical limitations,poses a great challenge for any wave system in imaging,wave transport,and dynamics.Originally formulated in linear optics,the Abbe limit can be broken using nonlinear optical interactions.We extend the Abbe theory into a nonlinear regime and experimentally demonstrate a far-field,label-free,and scan-free super-resolution imaging technique based on nonlinear four-wave mixing to retrieve near-field scattered evanescent waves,achieving a sub-wavelength resolution ofλ∕5.6.This method paves the way for numerous new applications in biomedical imaging,semiconductor metrology,and photolithography.展开更多
The idea of a slot waveguide amplifier based on erbium-doped tellurite glass is first theoretically discussed in this work.Choosing the horizontal slot for low propagation loss,the TM mode profile compressed in the in...The idea of a slot waveguide amplifier based on erbium-doped tellurite glass is first theoretically discussed in this work.Choosing the horizontal slot for low propagation loss,the TM mode profile compressed in the insertion layer was simulated,and the gain characteristics of the slot waveguide amplifier were calculated.Combining the capacity to confine light locally and the merits of tellurite glass as an emission host,this optimized amplifier shows enhanced interactions between the electric field and erbium ions and achieves a net gain of 15.21 dB for the 0.01 mW input light at 1530 nm,implying great promise of a high-performance device.展开更多
Silicon-based light sources, including light-emitting diodes(LEDs) and laser diodes(LDs) for information transmission, are urgently needed for developing monolithic integrated silicon photonics. Silicon with erbium io...Silicon-based light sources, including light-emitting diodes(LEDs) and laser diodes(LDs) for information transmission, are urgently needed for developing monolithic integrated silicon photonics. Silicon with erbium ions(Er^(3+)) doped by ion implantation is considered a promising approach, but it suffers from an extremely low quantum efficiency. Here we report an electrically pumped superlinear emission at 1.54 μm from Er/O-doped silicon planar LEDs, which are produced by applying a new deep cooling process. Stimulated emission at room temperature is realized with a low threshold current of ~6 mA(~0.8 A∕cm^(2)). Time-resolved photoluminescence and photocurrent results have revealed the complex carrier transfer dynamics by relaxing electrons from the Si conduction band to the Er^(3+) ion. This picture differs from the frequently assumed energy transfer via electron–hole pair recombination of the silicon host. Moreover, the amplified emission from the LEDs is likely due to a quasi-continuous Er/O-related donor band created by the deep cooling technique. This work paves the way for fabricating superluminescent diodes or efficient LEDs at communication wavelengths based on rare-earth-doped silicon.展开更多
基金Supported by the Innovation Program of Shanghai Municipal Education Commission(Grant No.2019-01-07-00-02-E00075)the Key R&D Program of Zhejiang Province(Grant No.2019C01155)the National Natural Science Foundation of China(Grant No.61874072).
文摘Fabrication of atomic dopant wires at large scale is challenging.We explored the feasibility to fabricate atomic dopant wires by nano-patterning self-assembled dopant carrying molecular monolayers via a resist-free lithographic approach.The resist-free lithography is to use electron beam exposure to decompose hydrocarbon contaminants in vacuum chamber into amorphous carbon that serves as an etching mask for nanopatterning the phosphorus-bearing monolayers.Dopant wires were fabricated in silicon by patterning diethyl vinylphosphonate monolayers into lines with a width ranging from 1 μm down to 8 nm.The dopants were subsequently driven into silicon to form dopant wires by rapid thermal annealing.Electrical measurements show a linear correlation between wire width and conductance,indicating the success of the monolayer patterning process at nanoscale.The dopant wires can be potentially scaled down to atomic scale if the dopant thermal diffusion can be mitigated.
基金National Natural Science Foundation of China,Grant/Award Numbers:52090030,52090031,92164106,U22A2076Shanxi-Zheda Institute of Advanced Materials and Chemical Engineering,Grant/Award Number: 2022SZ-TD011+1 种基金National KeyResearch and Development Program ofChina, Grant/Award Numbers:2022YFA1204300, 2022YFA1204304,2022YFA1204900Fundamental ResearchFunds for the Central Universities,Grant/Award Number: 2021FZZX001-17。
文摘The demand for high-performance X-ray detectors leads to material innovationfor efficient photoelectric conversion and carrier transfer. However, currentX-ray detectors are often susceptible to chemical and irradiation instability,complex fabrication processes, hazardous components, and difficult compatibility.Here, we investigate a two-dimensional (2D) material with a relativelylow atomic number, Ti_(3)C_(2)T_(x) MXenes, and single crystal silicon for X-ray detectionand single-pixel imaging (SPI). We fabricate a Ti_(3)C_(2)T_(x) MXene/Si X-raydetector demonstrating remarkable optoelectronic performance. This detectorexhibits a sensitivity of 1.2 × 10^(7) μC Gyair^(-1) cm^(-2), a fast response speed with arise time of 31 μs, and an incredibly low detection limit of 2.85 nGyair s^(-1).These superior performances are attributed to the unique charge couplingbehavior under X-ray irradiation via intrinsic polaron formation. The deviceremains stable even after 50 continuous hours of high-dose X-ray irradiation.Our device fabrication process is compatible with silicon-based semiconductortechnology. Our work suggests new directions for eco-friendly X-ray detectorsand low-radiation imaging system.
基金This work was supported by the National Key Research and Development Program(Grant Nos.2016YFA0302500 and 2017YFA0303700)National Natural Science Foundation of China(Grant Nos.92050113 and 11674228)Shanghai MEC Scientific Innovation Program(Grant No.E00075).
文摘Abbe’s resolution limit,one of the best-known physical limitations,poses a great challenge for any wave system in imaging,wave transport,and dynamics.Originally formulated in linear optics,the Abbe limit can be broken using nonlinear optical interactions.We extend the Abbe theory into a nonlinear regime and experimentally demonstrate a far-field,label-free,and scan-free super-resolution imaging technique based on nonlinear four-wave mixing to retrieve near-field scattered evanescent waves,achieving a sub-wavelength resolution ofλ∕5.6.This method paves the way for numerous new applications in biomedical imaging,semiconductor metrology,and photolithography.
基金supported by the National Natural Science Foundation of China(NSFC)(No.61975221)the Shanghai Science and Technology International Cooperation Fund(No.19520743900).
文摘The idea of a slot waveguide amplifier based on erbium-doped tellurite glass is first theoretically discussed in this work.Choosing the horizontal slot for low propagation loss,the TM mode profile compressed in the insertion layer was simulated,and the gain characteristics of the slot waveguide amplifier were calculated.Combining the capacity to confine light locally and the merits of tellurite glass as an emission host,this optimized amplifier shows enhanced interactions between the electric field and erbium ions and achieves a net gain of 15.21 dB for the 0.01 mW input light at 1530 nm,implying great promise of a high-performance device.
基金National Natural Science Foundation of China(61790583,61874043,61874072,21703140)Special-key project of the“Innovative Research Plan”+1 种基金Shanghai Municipality Bureau of Education(2019-01-07-00-02-E00075)Aero-Science Fund(201824X001)。
文摘Silicon-based light sources, including light-emitting diodes(LEDs) and laser diodes(LDs) for information transmission, are urgently needed for developing monolithic integrated silicon photonics. Silicon with erbium ions(Er^(3+)) doped by ion implantation is considered a promising approach, but it suffers from an extremely low quantum efficiency. Here we report an electrically pumped superlinear emission at 1.54 μm from Er/O-doped silicon planar LEDs, which are produced by applying a new deep cooling process. Stimulated emission at room temperature is realized with a low threshold current of ~6 mA(~0.8 A∕cm^(2)). Time-resolved photoluminescence and photocurrent results have revealed the complex carrier transfer dynamics by relaxing electrons from the Si conduction band to the Er^(3+) ion. This picture differs from the frequently assumed energy transfer via electron–hole pair recombination of the silicon host. Moreover, the amplified emission from the LEDs is likely due to a quasi-continuous Er/O-related donor band created by the deep cooling technique. This work paves the way for fabricating superluminescent diodes or efficient LEDs at communication wavelengths based on rare-earth-doped silicon.
