A substrate hot holes injection method is used to quantitatively examine the roles of electrons and holes separately in thin gate oxides breakdown.The shift of threshold voltage under different stress is discussed.It ...A substrate hot holes injection method is used to quantitatively examine the roles of electrons and holes separately in thin gate oxides breakdown.The shift of threshold voltage under different stress is discussed.It is indicated that positive charges are trapped in SiO 2 while hot electrons are necessary for SiO 2 breakdown.The anode holes injection model and the electron traps generation model is linked into a consistent model,describing the oxide wearout as an electron correlated holes trap creation process.The results show that the limiting factor in thin gate oxides breakdown depends on the balance between the amount of injected hot electrons and holes.The gate oxides breakdown is a two step process.The first step is hot electron's breaking Si-O bonds and producing some dangling bonds to be holes traps.Then the holes are trapped and a conducted path is produced in the oxides.The joint effect of hot electrons and holes makes the thin gate oxides breakdown complete.展开更多
Lead halide perovskites have some unique properties which are very promising for optoelectronic applications such as solar cells. LEDs and lasers. One important and expected application of perovskite halide semiconduc...Lead halide perovskites have some unique properties which are very promising for optoelectronic applications such as solar cells. LEDs and lasers. One important and expected application of perovskite halide semiconductors is solar cell operation including hot carriers. This advanced solar cell concept allows overcoming the Shockley-Queisser efficiency limit, thereby achieving energy conversion efficiency as high as 66% by extracting hot carriers. Understanding ultrafast photoexcited carrier dynamics and extraction in lead halide perovskites is crucial for these applications. Here, we clarify the hot carrier cooling and transfer dynamics in all-inorganic cesium lead iodide （CsPbI3） perovskite using transient absorption spectroscopy and Al2O3, poly（3-hexylthiophene-2,5-diyl） （P3HT） and TiO2 as selective contacts. We find that slow hot carrier cooling occurs on a timescale longer than 10 ps in the cases of CsPbI3/AI203 and CsPbI3/TiO2, which is attributed to hot phonon bottleneck for the high photoexcited carrier density. An efficient ultrafast hole transfer from CsPbI3 to the P3HT hole extracting layer is observed. These results suggest that hot holes can be extracted by appropriate selective contacts before energy dissipation into the halide perovskite lattice and that CsPbl3 has a potential for hot carrier solar cell applications.展开更多
Compared with the widespread exploitation of hot electrons in plasmonic nanoparticles(NPs),hot holes generated from plasmonic metal interband transitions,are often overlooked in photoelectrochemistry,including photoel...Compared with the widespread exploitation of hot electrons in plasmonic nanoparticles(NPs),hot holes generated from plasmonic metal interband transitions,are often overlooked in photoelectrochemistry,including photoelectrochemical sensing.Motivated by the subtle spectral overlap between the characteristic plasmonic bands of Ag NPs and interband transitions of Au,herein,we construct unusual core-shell Ag@Au NPs via an anti-galvanic reaction to promote the generation of hot holes.Benefiting from the unique plasmon resonances of Ag cores in specific wavelength regimes,Ag@Au can excite multiplied hot holes while Au cannot under the same conditions.With satisfactory accuracy and good practicability,the photoelectrochemical sensing platform based on Ag@Au NPs possesses a detection limit of 77 nmol/L for glucose,exhibiting significantly higher sensitivity compared to that using Au NPs.This work exemplifies the applications of interband hot-hole accumulation initiated by plasmons and may inspire more strategies to explore the utilization of hot holes in photoelectrochemistry.展开更多
Plasmonic nanostructures have been widely used for photochemical conversions due to their unique and easy-tuning optical properties in visible and near-infrared range.Compared with the plasmon-generated hot electrons,...Plasmonic nanostructures have been widely used for photochemical conversions due to their unique and easy-tuning optical properties in visible and near-infrared range.Compared with the plasmon-generated hot electrons,the hot holes usually have a shorter lifetime,which makes them more difficult to drive redox reactions.This review focuses on the photochemistry driven by the plasmon-generated hot holes.First,we discuss the generation and energy distribution of the plasmon-generated hot carriers,especially hot holes.Then,the dynamics of the hot holes are discussed at the interface between plasmonic metal and semiconductor or adsorbed molecules.Afterwards,the utilization of these hot holes in redox reactions is reviewed on the plasmon-semiconductor heterostructures as well as on the surface of the molecule-adsorbed plasmonic metals.Finally,the remaining challenges and future perspectives in this field are presented.This review will be helpful for further improving the efficiency of the photochemical reactions involving the plasmon-generated hot holes and expanding the applications of these hot holes in varieties of chemical reactions,especially the ones with high conversion rate and selectivity.展开更多
The behaviours of three types of hot-hole injections in ultrashort channel lightly doped drain （LDD） nMOSFETs with ultrathin oxide under an alternating stress have been compared. The three types of hot-hole injectio...The behaviours of three types of hot-hole injections in ultrashort channel lightly doped drain （LDD） nMOSFETs with ultrathin oxide under an alternating stress have been compared. The three types of hot-hole injections, i.e. low gate voltage hot hole injection （LGVHHI）, gate-induced drain leakage induced hot-hole injection （GIDLIHHI） and substrate hot-hole injection （SHHI）, have different influences on the devices damaged already by the previous hot electron injection （HEI） because of the different locations of trapping holes and interface states induced by the three types of injections, i.e. three types of stresses. Experimental results show that GIDLIHHI and LGVHHI cannot recover the degradation of electron trapping, but SHHI can. Although SHHI can recover the device＇s performance, the recovery is slight and reaches saturation quickly, which is suggested here to be attributed to the fact that trapped holes are too few and the equilibrium is reached between the trapping and releasing of holes which can be set up quickly in the ultrathin oxide.展开更多
The degradation of gate-induced drain leakage （GIDL） current in LDD nMOSFET under hot holes stress is studied in depth based on its parameter IDIFF. IDIFF is the difference of GIDL currents measured under two condit...The degradation of gate-induced drain leakage （GIDL） current in LDD nMOSFET under hot holes stress is studied in depth based on its parameter IDIFF. IDIFF is the difference of GIDL currents measured under two conditions of drain voltage VD = 1.4 V and gate voltage VG = -1.4 V while FoG is fixed. After the stress GIDL currents decay due to holes trapping in the oxide around the gate-to-drain overlap region. These trapped holes diminish A Ex which is the deference of the lateral electrical field of these two symmetrical measurement conditions in the overlap region so as to make IDIFF lessening. IOIFF extracted from GIDL currents decreases with increasing stress time t. The degradation shifts of IDIFF, MAX （A IDWF, MAX） follows a power law against t： △IDIFF＇ MAX （x t^m, m = 0.3. Hot electron stress is performed to validate the related mechanism.展开更多
The hot-carrier degradation for 90 nm gate length lightly-doped drain （LDD） NMOSFET with ultra-thin （1.4 nm） gate oxide under the low gate voltage （LGV） （at Vg = Vth, where Yth is the threshold voltage） stress...The hot-carrier degradation for 90 nm gate length lightly-doped drain （LDD） NMOSFET with ultra-thin （1.4 nm） gate oxide under the low gate voltage （LGV） （at Vg = Vth, where Yth is the threshold voltage） stress has been investigated. It is found that the drain current decreases and the threshold voltage increases after the LGV （Vg = Vth） stress. The results are opposite to the degradation phenomena of conventional NMOSFET for the case of this stress. By analysing the gate-induced drain leakage （GIDL） current before and after stresses, it is confirmed that under the LGV stress in ultra-short gate LDD-NMOSFET with ultra-thin gate oxide, the hot holes are trapped at interface in the LDD region and cannot shorten the channel to mask the influence of interface states as those in conventional NMOSFET do, which leads to the different degradation phenomena from those of the conventional NMOS devices. This paper also discusses the degradation in the 90 nm gate length LDD-NMOSFET with 1.4 nm gate oxide under the LGV stress at Yg = Yth with various drain biases. Experimental results show that the degradation slopes （n） range from 0.21 to 0.41. The value of n is less than that of conventional MOSFET （0.5 - 0.6） and also that of the long gate length LDD MOSFET （- 0.8）.展开更多
The gas turbine blades with diffusion film cooling holes are newlydeveloped blade struc- tures in the hydrogen combustion gas turbine,which has an extremely high inlet gas temperature (1700 deg. C). TheFluid Machinery...The gas turbine blades with diffusion film cooling holes are newlydeveloped blade struc- tures in the hydrogen combustion gas turbine,which has an extremely high inlet gas temperature (1700 deg. C). TheFluid Machinery Laboratory of Nagoya Institute o Technology conductedfirstly a new research o the turbulent flow field over the gasturbine blade with diffusion film cooling holes in Japan. Normal-typeand X-ray hot wires were applied in the measurement of the flowfield.展开更多
Hot wire measurements and flow visualization are presented for studying the turbulent flow field over a flat gas turbine film cooling blade with lateral expanded holes. Three mass flux ratios of jet to free stream, M ...Hot wire measurements and flow visualization are presented for studying the turbulent flow field over a flat gas turbine film cooling blade with lateral expanded holes. Three mass flux ratios of jet to free stream, M = 0.5, 0.89, 1.5, are tested. The streamwise velocity, the turbulent intensities and the Reynolds shear stress are measured. The effect of the lateral expanded holes on the improvement of the turbulent flow field for film cooling of gas turbines can be analyzed from the measured spatial di...展开更多
文摘A substrate hot holes injection method is used to quantitatively examine the roles of electrons and holes separately in thin gate oxides breakdown.The shift of threshold voltage under different stress is discussed.It is indicated that positive charges are trapped in SiO 2 while hot electrons are necessary for SiO 2 breakdown.The anode holes injection model and the electron traps generation model is linked into a consistent model,describing the oxide wearout as an electron correlated holes trap creation process.The results show that the limiting factor in thin gate oxides breakdown depends on the balance between the amount of injected hot electrons and holes.The gate oxides breakdown is a two step process.The first step is hot electron's breaking Si-O bonds and producing some dangling bonds to be holes traps.Then the holes are trapped and a conducted path is produced in the oxides.The joint effect of hot electrons and holes makes the thin gate oxides breakdown complete.
基金supported by the CREST program of Japan Science and Technology Agency(JST)supported by KAKENHI from the Japan Society for the Promotion of Science(JSPS)under the Grant-in-Aid for Young Scientists B(Grant Number JP16K17947)
文摘Lead halide perovskites have some unique properties which are very promising for optoelectronic applications such as solar cells. LEDs and lasers. One important and expected application of perovskite halide semiconductors is solar cell operation including hot carriers. This advanced solar cell concept allows overcoming the Shockley-Queisser efficiency limit, thereby achieving energy conversion efficiency as high as 66% by extracting hot carriers. Understanding ultrafast photoexcited carrier dynamics and extraction in lead halide perovskites is crucial for these applications. Here, we clarify the hot carrier cooling and transfer dynamics in all-inorganic cesium lead iodide （CsPbI3） perovskite using transient absorption spectroscopy and Al2O3, poly（3-hexylthiophene-2,5-diyl） （P3HT） and TiO2 as selective contacts. We find that slow hot carrier cooling occurs on a timescale longer than 10 ps in the cases of CsPbI3/AI203 and CsPbI3/TiO2, which is attributed to hot phonon bottleneck for the high photoexcited carrier density. An efficient ultrafast hole transfer from CsPbI3 to the P3HT hole extracting layer is observed. These results suggest that hot holes can be extracted by appropriate selective contacts before energy dissipation into the halide perovskite lattice and that CsPbl3 has a potential for hot carrier solar cell applications.
基金financially supported by the National Natural Science Foundation of China(Nos.22074038 and 21807032)the Natural Science Foundation of Hunan Province(No.2019J30007),and the Fundamental Research Funds for the Central Universities.
文摘Compared with the widespread exploitation of hot electrons in plasmonic nanoparticles(NPs),hot holes generated from plasmonic metal interband transitions,are often overlooked in photoelectrochemistry,including photoelectrochemical sensing.Motivated by the subtle spectral overlap between the characteristic plasmonic bands of Ag NPs and interband transitions of Au,herein,we construct unusual core-shell Ag@Au NPs via an anti-galvanic reaction to promote the generation of hot holes.Benefiting from the unique plasmon resonances of Ag cores in specific wavelength regimes,Ag@Au can excite multiplied hot holes while Au cannot under the same conditions.With satisfactory accuracy and good practicability,the photoelectrochemical sensing platform based on Ag@Au NPs possesses a detection limit of 77 nmol/L for glucose,exhibiting significantly higher sensitivity compared to that using Au NPs.This work exemplifies the applications of interband hot-hole accumulation initiated by plasmons and may inspire more strategies to explore the utilization of hot holes in photoelectrochemistry.
基金This work was supported by National Natural Science Foundation of China(No.11974180)Key University Science Research Project of Jiangsu Province(No.17KJA150005)+1 种基金Six Talent Peaks Project in Jiangsu Province(No.XCL-038)Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.KYCX20_1060).
文摘Plasmonic nanostructures have been widely used for photochemical conversions due to their unique and easy-tuning optical properties in visible and near-infrared range.Compared with the plasmon-generated hot electrons,the hot holes usually have a shorter lifetime,which makes them more difficult to drive redox reactions.This review focuses on the photochemistry driven by the plasmon-generated hot holes.First,we discuss the generation and energy distribution of the plasmon-generated hot carriers,especially hot holes.Then,the dynamics of the hot holes are discussed at the interface between plasmonic metal and semiconductor or adsorbed molecules.Afterwards,the utilization of these hot holes in redox reactions is reviewed on the plasmon-semiconductor heterostructures as well as on the surface of the molecule-adsorbed plasmonic metals.Finally,the remaining challenges and future perspectives in this field are presented.This review will be helpful for further improving the efficiency of the photochemical reactions involving the plasmon-generated hot holes and expanding the applications of these hot holes in varieties of chemical reactions,especially the ones with high conversion rate and selectivity.
文摘The behaviours of three types of hot-hole injections in ultrashort channel lightly doped drain （LDD） nMOSFETs with ultrathin oxide under an alternating stress have been compared. The three types of hot-hole injections, i.e. low gate voltage hot hole injection （LGVHHI）, gate-induced drain leakage induced hot-hole injection （GIDLIHHI） and substrate hot-hole injection （SHHI）, have different influences on the devices damaged already by the previous hot electron injection （HEI） because of the different locations of trapping holes and interface states induced by the three types of injections, i.e. three types of stresses. Experimental results show that GIDLIHHI and LGVHHI cannot recover the degradation of electron trapping, but SHHI can. Although SHHI can recover the device＇s performance, the recovery is slight and reaches saturation quickly, which is suggested here to be attributed to the fact that trapped holes are too few and the equilibrium is reached between the trapping and releasing of holes which can be set up quickly in the ultrathin oxide.
基金supported by the Specialized Research Fund of the Education Department of Shaanxi Province,China(No.11JK0902)the Innovational Fund for Applied Materials of Xi'an,China(No.XA-AM-201012)
文摘The degradation of gate-induced drain leakage （GIDL） current in LDD nMOSFET under hot holes stress is studied in depth based on its parameter IDIFF. IDIFF is the difference of GIDL currents measured under two conditions of drain voltage VD = 1.4 V and gate voltage VG = -1.4 V while FoG is fixed. After the stress GIDL currents decay due to holes trapping in the oxide around the gate-to-drain overlap region. These trapped holes diminish A Ex which is the deference of the lateral electrical field of these two symmetrical measurement conditions in the overlap region so as to make IDIFF lessening. IOIFF extracted from GIDL currents decreases with increasing stress time t. The degradation shifts of IDIFF, MAX （A IDWF, MAX） follows a power law against t： △IDIFF＇ MAX （x t^m, m = 0.3. Hot electron stress is performed to validate the related mechanism.
基金Project supported by the National High Technology Research and Development Program of China （Grant No 2003AA1Z1630） and the National Natural Science Foundation of China （Grant No 60376024）.
文摘The hot-carrier degradation for 90 nm gate length lightly-doped drain （LDD） NMOSFET with ultra-thin （1.4 nm） gate oxide under the low gate voltage （LGV） （at Vg = Vth, where Yth is the threshold voltage） stress has been investigated. It is found that the drain current decreases and the threshold voltage increases after the LGV （Vg = Vth） stress. The results are opposite to the degradation phenomena of conventional NMOSFET for the case of this stress. By analysing the gate-induced drain leakage （GIDL） current before and after stresses, it is confirmed that under the LGV stress in ultra-short gate LDD-NMOSFET with ultra-thin gate oxide, the hot holes are trapped at interface in the LDD region and cannot shorten the channel to mask the influence of interface states as those in conventional NMOSFET do, which leads to the different degradation phenomena from those of the conventional NMOS devices. This paper also discusses the degradation in the 90 nm gate length LDD-NMOSFET with 1.4 nm gate oxide under the LGV stress at Yg = Yth with various drain biases. Experimental results show that the degradation slopes （n） range from 0.21 to 0.41. The value of n is less than that of conventional MOSFET （0.5 - 0.6） and also that of the long gate length LDD MOSFET （- 0.8）.
文摘The gas turbine blades with diffusion film cooling holes are newlydeveloped blade struc- tures in the hydrogen combustion gas turbine,which has an extremely high inlet gas temperature (1700 deg. C). TheFluid Machinery Laboratory of Nagoya Institute o Technology conductedfirstly a new research o the turbulent flow field over the gasturbine blade with diffusion film cooling holes in Japan. Normal-typeand X-ray hot wires were applied in the measurement of the flowfield.
文摘Hot wire measurements and flow visualization are presented for studying the turbulent flow field over a flat gas turbine film cooling blade with lateral expanded holes. Three mass flux ratios of jet to free stream, M = 0.5, 0.89, 1.5, are tested. The streamwise velocity, the turbulent intensities and the Reynolds shear stress are measured. The effect of the lateral expanded holes on the improvement of the turbulent flow field for film cooling of gas turbines can be analyzed from the measured spatial di...
