Thin nanocomposite fflms based on tin dioxide with a low content of zinc oxide(0.5–5 mol.%)were obtained by the sol–gel method.The synthesized fflms are 300–600 nm thick and contains pore sizes of 19–29 nm.The res...Thin nanocomposite fflms based on tin dioxide with a low content of zinc oxide(0.5–5 mol.%)were obtained by the sol–gel method.The synthesized fflms are 300–600 nm thick and contains pore sizes of 19–29 nm.The resulting ZnO–SnO_(2) fflms were comprehensively studied by atomic force and Kelvin probe force microscopy,X-ray diffraction,scanning electron microscopy,and high-resolution X-ray photoelectron spectroscopy spectra.The photoconductivity parameters on exposure to light with a wavelength of 470 nm were also studied.The study of the photosensitivity kinetics of ZnO–SnO_(2) fflms showed that the fflm with the Zn:Sn ratio equal to 0.5:99.5 has the minimum value of the charge carrier generation time constant.Measurements of the activation energy of the conductivity,potential barrier,and surface potential of ZnO–SnO_(2) fflms showed that these parameters have maxima at ZnO concentrations of 0.5 mol.%and 1 mol.%.Films with 1 mol.%ZnO exhibit high response values when exposed to 5–50 ppm of nitrogen dioxide at operating temperatures of 200℃ and 250℃.展开更多
AlGaN-based light-emitting diodes(LEDs)on offcut substrates enhance radiative emission via forming carrier localization centers in multiple quantum wells(MQWs).This study introduces the carrier transport barrier conce...AlGaN-based light-emitting diodes(LEDs)on offcut substrates enhance radiative emission via forming carrier localization centers in multiple quantum wells(MQWs).This study introduces the carrier transport barrier concept,accessing its impact on the quantum efficiency of LEDs grown on different offcut sapphire substrates.A significantly enhanced internal quantum efficiency(IQE)of 83.1%is obtained from MQWs on the 1°offcut sapphire,almost twice that of the controlled 0.2°offcut sample.Yet,1°offcut LEDs have higher turn-on voltage and weaker electroluminescence than 0.2°ones.Theoretical calculations demonstrate the existence of a potential barrier on the current path around the step-induced Ga-rich stripes.Ga-rich stripes reduce the turn-on voltage but restrict sufficient driving current,impacting LED performance.展开更多
Nanoscale superlattice has been investigated theoretically. It has been shown that the deformation effects on the energy spectrum of nanoscale superlattice by changing the interatomic distances as well as varying the ...Nanoscale superlattice has been investigated theoretically. It has been shown that the deformation effects on the energy spectrum of nanoscale superlattice by changing the interatomic distances as well as varying the width and height of the potential barrier. The potential deformation has been estimated. It has been shown that for different edges of forbidden bands the deformation potential has different values. It has been also analyzed the dependence of the effective mass on energy. It has been determined that the effective mass crosses periodically the zero mark. It has been concluded that this phenomena contributes to the periodic change of the oscillation frequency de Haas-van Alphen effect.展开更多
The performance of a piecewise-stressed ZnO piezoelectric semiconductor nano?ber is studied with the multi-?eld coupling theory. The ?elds produced by equal and opposite forces as well as sinusoidally distributed forc...The performance of a piecewise-stressed ZnO piezoelectric semiconductor nano?ber is studied with the multi-?eld coupling theory. The ?elds produced by equal and opposite forces as well as sinusoidally distributed forces are examined. Speci?c distributions of potential barriers, wells, and regions with effective polarization charges are found. The results are fundamental for the mechanical tuning on piezoelectric semiconductor devices and piezotronics.展开更多
The charge transfer efficiency improvement method is introduced by optimizing the electrical potential distribution under the transfer gate along the charge transfer path. A non-uniform doped transfer transistor chan-...The charge transfer efficiency improvement method is introduced by optimizing the electrical potential distribution under the transfer gate along the charge transfer path. A non-uniform doped transfer transistor chan- nel is introduced to provide an ascending electrical potential gradient in the transfer transistor channel. With the adjustments to the overlap length between the R1 region and the transfer gate, the doping dose of the R1 region, and the overlap length between the anti-punch-through （APT） implantations and transfer gate, the potential barrier and potential pocket in the connecting region of transfer transistor channel and the pinned photodiode （PPD） are reduced to improve the electrical potential connection. The simulation results show that the percentage of residual charges to total charges drops from 1/10^4 to 1/10^7, and the transfer time is reduced from 500 to 110 ns. This means the charge transfer efficiency is improved.展开更多
The impact of potential barrier distribution on the transient performance of a static induction thyristor （SITH） in a channel determined by geometrical parameters and applied bias voltage is studied theoretically an...The impact of potential barrier distribution on the transient performance of a static induction thyristor （SITH） in a channel determined by geometrical parameters and applied bias voltage is studied theoretically and experimentally. The analytical expressions of potential barrier height and the I-V characteristics of the SITH are also derived. The main factors that influence the transient performance of the SITH between the blocking and conducting states, as well as the mechanism underlying the transient process, is thoroughly investigated. This is useful in designing, fabricating, optimizing and applying SITHs properly.展开更多
The relationship of electrical properties of Mn-doped Ba_(0.92)Ca_(0.08)TiO_3PTCR (positive temperature coefficient resistance) ceramics with two sintering schedules wasdiscussed. Using TEM (transmission electron micr...The relationship of electrical properties of Mn-doped Ba_(0.92)Ca_(0.08)TiO_3PTCR (positive temperature coefficient resistance) ceramics with two sintering schedules wasdiscussed. Using TEM (transmission electron microscope) combined with EDS (energy dispersive X-rayspectrometer), the Mn ions distributed at grain boundaries were analyzed. The results show that thePTCR effect of Mn-doped PTCR ceramics is more dependent on the sintering schedule than those of Mnfree. The phenomenon may be caused by the valence states variance of Mn ions segregated at the grainboundaries.展开更多
基金The authors are grateful to the PHENMA 2021–2022 conference for the possibility of manuscript publication.The research was carried out at the expense of the grant of the Russian Science Foundation No.22-29-00621,(https://rscf.ru/project/22-29-00621/)at the Southern Federal University.
文摘Thin nanocomposite fflms based on tin dioxide with a low content of zinc oxide(0.5–5 mol.%)were obtained by the sol–gel method.The synthesized fflms are 300–600 nm thick and contains pore sizes of 19–29 nm.The resulting ZnO–SnO_(2) fflms were comprehensively studied by atomic force and Kelvin probe force microscopy,X-ray diffraction,scanning electron microscopy,and high-resolution X-ray photoelectron spectroscopy spectra.The photoconductivity parameters on exposure to light with a wavelength of 470 nm were also studied.The study of the photosensitivity kinetics of ZnO–SnO_(2) fflms showed that the fflm with the Zn:Sn ratio equal to 0.5:99.5 has the minimum value of the charge carrier generation time constant.Measurements of the activation energy of the conductivity,potential barrier,and surface potential of ZnO–SnO_(2) fflms showed that these parameters have maxima at ZnO concentrations of 0.5 mol.%and 1 mol.%.Films with 1 mol.%ZnO exhibit high response values when exposed to 5–50 ppm of nitrogen dioxide at operating temperatures of 200℃ and 250℃.
基金supported by the National Natural Science Foundation of China(No.62104233)the Natural Science Foundation of Ningbo(No.2022J298)+1 种基金the Zhejiang Provincial Natural Science Foundation(No.LQ21F040004)the Ningbo Innovation 2025 Major Project(No.2021Z082)。
文摘AlGaN-based light-emitting diodes(LEDs)on offcut substrates enhance radiative emission via forming carrier localization centers in multiple quantum wells(MQWs).This study introduces the carrier transport barrier concept,accessing its impact on the quantum efficiency of LEDs grown on different offcut sapphire substrates.A significantly enhanced internal quantum efficiency(IQE)of 83.1%is obtained from MQWs on the 1°offcut sapphire,almost twice that of the controlled 0.2°offcut sample.Yet,1°offcut LEDs have higher turn-on voltage and weaker electroluminescence than 0.2°ones.Theoretical calculations demonstrate the existence of a potential barrier on the current path around the step-induced Ga-rich stripes.Ga-rich stripes reduce the turn-on voltage but restrict sufficient driving current,impacting LED performance.
文摘Nanoscale superlattice has been investigated theoretically. It has been shown that the deformation effects on the energy spectrum of nanoscale superlattice by changing the interatomic distances as well as varying the width and height of the potential barrier. The potential deformation has been estimated. It has been shown that for different edges of forbidden bands the deformation potential has different values. It has been also analyzed the dependence of the effective mass on energy. It has been determined that the effective mass crosses periodically the zero mark. It has been concluded that this phenomena contributes to the periodic change of the oscillation frequency de Haas-van Alphen effect.
基金Project supported by the National Natural Science Foundation of China(Nos.11672113 and 51435006)the Key Laboratory Project of Hubei Province of China(No.2016CFA073)
文摘The performance of a piecewise-stressed ZnO piezoelectric semiconductor nano?ber is studied with the multi-?eld coupling theory. The ?elds produced by equal and opposite forces as well as sinusoidally distributed forces are examined. Speci?c distributions of potential barriers, wells, and regions with effective polarization charges are found. The results are fundamental for the mechanical tuning on piezoelectric semiconductor devices and piezotronics.
基金Project supported by National Natural Science Foundation of China(Nos.61036004,61076024)
文摘The charge transfer efficiency improvement method is introduced by optimizing the electrical potential distribution under the transfer gate along the charge transfer path. A non-uniform doped transfer transistor chan- nel is introduced to provide an ascending electrical potential gradient in the transfer transistor channel. With the adjustments to the overlap length between the R1 region and the transfer gate, the doping dose of the R1 region, and the overlap length between the anti-punch-through （APT） implantations and transfer gate, the potential barrier and potential pocket in the connecting region of transfer transistor channel and the pinned photodiode （PPD） are reduced to improve the electrical potential connection. The simulation results show that the percentage of residual charges to total charges drops from 1/10^4 to 1/10^7, and the transfer time is reduced from 500 to 110 ns. This means the charge transfer efficiency is improved.
基金Project supported by the Scientific and Technological Supporting Program of Gansu Province,China(No.097GKCA052)
文摘The impact of potential barrier distribution on the transient performance of a static induction thyristor （SITH） in a channel determined by geometrical parameters and applied bias voltage is studied theoretically and experimentally. The analytical expressions of potential barrier height and the I-V characteristics of the SITH are also derived. The main factors that influence the transient performance of the SITH between the blocking and conducting states, as well as the mechanism underlying the transient process, is thoroughly investigated. This is useful in designing, fabricating, optimizing and applying SITHs properly.
基金This work is financially supported by the Postdoctoral Research Foundation of the Chinese Education Ministry (No. 023202238)
文摘The relationship of electrical properties of Mn-doped Ba_(0.92)Ca_(0.08)TiO_3PTCR (positive temperature coefficient resistance) ceramics with two sintering schedules wasdiscussed. Using TEM (transmission electron microscope) combined with EDS (energy dispersive X-rayspectrometer), the Mn ions distributed at grain boundaries were analyzed. The results show that thePTCR effect of Mn-doped PTCR ceramics is more dependent on the sintering schedule than those of Mnfree. The phenomenon may be caused by the valence states variance of Mn ions segregated at the grainboundaries.
