Semiconductor materials and devices play an important role in modern science and technology.Historically,there would be neither microelectronics without silicon materials,nor high-speed communica-tion without compound...Semiconductor materials and devices play an important role in modern science and technology.Historically,there would be neither microelectronics without silicon materials,nor high-speed communica-tion without compound semiconductors such as GaAs and InP.Today,driven by the demand of highly advanced science and technology,the semiconductor material system has evolved into a new era.Wide band gap semiconductors represented by GaN and SiC,and ultra-wide band gap semiconductors represented by Ga_(2)O_(3) and diamond,have become predominant research areas of modern semiconductor science and technology.展开更多
As a promising ultra-wide bandgap semiconductor, gallium oxide(Ga_2O_3) has attracted increasing attention in recent years. The high theoretical breakdown electrical field(8 MV/cm), ultra-wide bandgap(～ 4.8 eV) and l...As a promising ultra-wide bandgap semiconductor, gallium oxide(Ga_2O_3) has attracted increasing attention in recent years. The high theoretical breakdown electrical field(8 MV/cm), ultra-wide bandgap(～ 4.8 eV) and large Baliga's figure of merit(BFOM) of Ga_2O_3 make it a potential candidate material for next generation high-power electronics, including diode and field effect transistor(FET). In this paper, we introduce the basic physical properties of Ga_2O_3 single crystal, and review the recent research process of Ga_2O_3 based field effect transistors. Furthermore, various structures of FETs have been summarized and compared, and the potential of Ga_2O_3 is preliminary revealed. Finally, the prospect of the Ga_2O_3 based FET for power electronics application is analyzed.展开更多
As one of the ultra-wide bandgap {UWBG)semiconducting materials,gallium oxide has attractive properties with a wide bandgap of about 4.8 eV and a high breakdown field of about 8 MWcm,which offers an alternative platfo...As one of the ultra-wide bandgap {UWBG)semiconducting materials,gallium oxide has attractive properties with a wide bandgap of about 4.8 eV and a high breakdown field of about 8 MWcm,which offers an alternative platform for various applications such as high performance power switches,RF amplifiers,solar blind photodetectors,and harsh environment signal processing.展开更多
Radio frequency/microwave-directed energy sources using wide bandgap SiC photoconductive semiconductors have attracted much attention due to their unique advantages of high-power output and multi-parameter adjustable ...Radio frequency/microwave-directed energy sources using wide bandgap SiC photoconductive semiconductors have attracted much attention due to their unique advantages of high-power output and multi-parameter adjustable ability.Over the past several years,benefitting from the sustainable innovations in laser technology and the significant progress in materials technology,megawatt-class output power electrical pulses with a flexible frequency in the P and L microwave wavebands have been achieved by photoconductive semiconductor devices.Here,we mainly summarize and review the recent progress of the high-power photonic microwave generation based on the SiC photoconductive semiconductor devices in the linear modulation mode,including the mechanism,system architecture,critical technology,and experimental demonstration of the proposed high-power photonic microwave sources.The outlooks and challenges for the future of multi-channel power synthesis development of higher power photonic microwave using wide bandgap photoconductors are also discussed.展开更多
A new layered Cu-based oxychalcogenide Ba_3Fe_2O_5Cu_2S_2 has been synthesized and its magnetic and electronic properties were revealed. Ba_3Fe_2O_5Cu_2S_2 is built up by alternatively stacking [Cu_2S_2]^（2-） layers...A new layered Cu-based oxychalcogenide Ba_3Fe_2O_5Cu_2S_2 has been synthesized and its magnetic and electronic properties were revealed. Ba_3Fe_2O_5Cu_2S_2 is built up by alternatively stacking [Cu_2S_2]^（2-） layers and iron perovskite oxide[（FeO_2）（BaO）（FeO_2）]^（2-）layers along the c axis that are separated by barium ions with Fe^（3＋） fivefold coordinated by a square-pyramidal arrangement of oxygen. From the bond valence arguments, we inferred that in layered CuC h-based（Ch =S, Se, Te） compounds the ＋3 cation in perovskite oxide sheet prefers a square pyramidal site, while the lower valence cation prefers the square planar sites. The studies on susceptibility, transport, and optical reflectivity indicate that Ba_3Fe_2O_5Cu_2S_2 is an antiferromagnetic semiconductor with a Ne′el temperature of 121 K and an optical bandgap of 1.03 eV. The measurement of heat capacity from 10 K to room temperature shows no anomaly at 121 K. The Debye temperature is determined to be 113 K. Theoretical calculations indicate that the conduction band minimum is predominantly contributed by O 2p and 3 d states of Fe ions that antiferromagnetically arranged in FeO_2 layers. The Fe 3d states are located at lower energy and result in a narrow bandgap in comparison with that of the isostructural Sr_3Sc_2O_5Cu_2S_2.展开更多
TheⅡ-Ⅵbased magnetic semiconductors with a direct and wide optical bandgap are expected to show high potential for optical applications utilizing short wavelength laser diodes(LDs),such as 532-nm green and475-nm blu...TheⅡ-Ⅵbased magnetic semiconductors with a direct and wide optical bandgap are expected to show high potential for optical applications utilizing short wavelength laser diodes(LDs),such as 532-nm green and475-nm blue LDs.We have confirmed that the Faraday rotationθ_F in the ZnMnTe and ZnMnSe films deposited on quartz glass(QG)and sapphire(SA)substrates by using molecular beam epitaxy(MBE)is large near the absorption edge.This paper reports the magneto-optical properties of ZnMnTe and ZnMnSe films synthesized on the QG and SA substrates,and shows the result of a direct Faraday rotation observation successfully made for the ZnMnTe films under 1.28-kHz alternating magnetic fields.The optical absorption characteristics of the ZnMnTe films grown on the SA substrates by MBE are discussed by comparing them with the optical absorption properties and photoluminescence spectra of theⅡ-ⅥZnTe parent single crystals.展开更多
Theβ-LiGaO_(2)with an orthorhombic wurtzite-derived structure is a candidate ultrawide direct-bandgap semiconductor.In this work,using the non-adiabatic Allen-Heine-Cardona approach,we investigate the bandgap renorma...Theβ-LiGaO_(2)with an orthorhombic wurtzite-derived structure is a candidate ultrawide direct-bandgap semiconductor.In this work,using the non-adiabatic Allen-Heine-Cardona approach,we investigate the bandgap renormalization arising from electron-phonon coupling.We find a sizable zero-point motion correction of-0.362 eV to the gap atΓ,which is dominated by the contributions of long-wavelength longitudinal optical phonons.The bandgap ofβ-LiGaO_(2)decreases monotonically with increasing temperature.We investigate the optical spectra by comparing the model Bethe-Salpether equation method with the independent-particle approximation.The calculated optical spectra including electron-hole interactions exhibit strong excitonic effects,in qualitative agreement with the experiment.The contributing interband transitions and the binding energy for the excitonic states are analyzed.展开更多
The recent successful fabrication of two-dimensional(2D)CoO with nanometer-thickness motivates us to investigate monolayer CoO due to possible magnetic properties induced by Co atoms.Here,we employ first-principles ca...The recent successful fabrication of two-dimensional(2D)CoO with nanometer-thickness motivates us to investigate monolayer CoO due to possible magnetic properties induced by Co atoms.Here,we employ first-principles calculations to show that monolayer CoO is a 2D spin-spiral semiconductor with a honeycomb lattice.The calculated phonon dispersion reveals the monolayer's dynamical stability.Monolayer CoO exhibits a type-I spin-spiral magnetic ground state.The spinspiral state and the direct bandgap character are both robust under biaxial compressive strain(-5%)to tensile strain(5%).The bandgap varies only slightly under either compressive or tensile strain up to 5%.These results suggest a potential for applications in spintronic devices and offer a new platform to explore magnetism in the 2D limit.展开更多
Power-electronic devices are widely used in various applications, such as voltage and frequency control for transmitting and converting electric power. As these devices are becoming increasingly important, there is a ...Power-electronic devices are widely used in various applications, such as voltage and frequency control for transmitting and converting electric power. As these devices are becoming increasingly important, there is a need to reduce their losses and improve their performance to reduce electric power consumption. Current power semiconductor devices, such as inverters, are made of silicon (Si), but the performance of these Si power devices is reaching its limit due to physical properties and energy bandgap. To address this issue, recent developments in wide bandgap (WBG) semiconductor materials, such as silicon carbide (SiC) and gallium nitride (GaN), offer the potential for a new generation of power semiconductor devices that can perform significantly better than silicon-based devices. In this research, a green synthesized copper-zinc-tin-sulfide (CZTS) nanoparticle is proposed as a new WBG semiconductor material that could be used for optical and electronic devices. Its synthesis, consisting of the production methods and materials used, is discussed. The characterization is also discussed, and further research is recommended in the later sections to enable the continual advancement of this technology.展开更多
Over the last few years,great advances have been achieved in exploration of high-mobility two-dimensional(2D)semiconductors such as metal chalcogenide InSe and noble-transition-metal dichal-cogenide PdSe_(2).These mat...Over the last few years,great advances have been achieved in exploration of high-mobility two-dimensional(2D)semiconductors such as metal chalcogenide InSe and noble-transition-metal dichal-cogenide PdSe_(2).These materials are competitive candidates for constructing next-generation optoelec-tronic devices owing to their unique crystalline and electronic structures.Moreover,the optical and electronic properties of 2D materials can be efficiently modified via precisely engineering their band structures,which is critical for widening specific applications ranging from high-performance opto-electronics to catalysis and energy harvesting.In this review,we focus on the progress in bandgaps engineering of newly emerging high-mobility 2D semiconductors and their applications in optoelec-tronic devices,incorporating our recent study in the InSe and PdSe_(2)systems.First of all,we discuss the structure-property relationship of typical high-mobility 2D semiconductors(InSe and PdSe 2).Next,we analyze several viable strategies for bandgap engineering,including thickness,strain or pressure,alloying,heterostructure,surface modification,intercalation,and so on.Furthermore,we summarize the optoelectronic devices fabricated with such high-mobility 2D semiconductors.The conclusion and outlook in this topic are finally presented.This review aims to provide valuable insights in bandgap engineering of newly emerging 2D semiconductors and explore their potential in future optoelectronic applications.展开更多
文摘Semiconductor materials and devices play an important role in modern science and technology.Historically,there would be neither microelectronics without silicon materials,nor high-speed communica-tion without compound semiconductors such as GaAs and InP.Today,driven by the demand of highly advanced science and technology,the semiconductor material system has evolved into a new era.Wide band gap semiconductors represented by GaN and SiC,and ultra-wide band gap semiconductors represented by Ga_(2)O_(3) and diamond,have become predominant research areas of modern semiconductor science and technology.
基金supported by the National Natural Science Foundation of China(Nos.61521064,61522408,61574169,6 1334007,61474136,61574166)the Ministry of Science andTechnology of China(Nos.2016YFA0201803,2016YFA0203800,2017YFB0405603)+2 种基金the Key Research Program of Frontier Sciences of Chinese Academy of Sciences(Nos.QYZDB-SSWJSC048,QYZDY-SSW-JSC001)the Beijing Municipal Science and Technology Project(No.Z171100002017011)the Opening Project of the Key Laboratory of Microelectronic Devices&Integration Technology,Institute of Microelectronics of Chinese Academy of Sciences
文摘As a promising ultra-wide bandgap semiconductor, gallium oxide(Ga_2O_3) has attracted increasing attention in recent years. The high theoretical breakdown electrical field(8 MV/cm), ultra-wide bandgap(～ 4.8 eV) and large Baliga's figure of merit(BFOM) of Ga_2O_3 make it a potential candidate material for next generation high-power electronics, including diode and field effect transistor(FET). In this paper, we introduce the basic physical properties of Ga_2O_3 single crystal, and review the recent research process of Ga_2O_3 based field effect transistors. Furthermore, various structures of FETs have been summarized and compared, and the potential of Ga_2O_3 is preliminary revealed. Finally, the prospect of the Ga_2O_3 based FET for power electronics application is analyzed.
文摘As one of the ultra-wide bandgap {UWBG)semiconducting materials,gallium oxide has attractive properties with a wide bandgap of about 4.8 eV and a high breakdown field of about 8 MWcm,which offers an alternative platform for various applications such as high performance power switches,RF amplifiers,solar blind photodetectors,and harsh environment signal processing.
基金supported in part by the National Natural Science Foundation of China(Nos.62071477 and 62101577)the Natural Science Foundation of Hunan Province(No.2021JJ40660)。
文摘Radio frequency/microwave-directed energy sources using wide bandgap SiC photoconductive semiconductors have attracted much attention due to their unique advantages of high-power output and multi-parameter adjustable ability.Over the past several years,benefitting from the sustainable innovations in laser technology and the significant progress in materials technology,megawatt-class output power electrical pulses with a flexible frequency in the P and L microwave wavebands have been achieved by photoconductive semiconductor devices.Here,we mainly summarize and review the recent progress of the high-power photonic microwave generation based on the SiC photoconductive semiconductor devices in the linear modulation mode,including the mechanism,system architecture,critical technology,and experimental demonstration of the proposed high-power photonic microwave sources.The outlooks and challenges for the future of multi-channel power synthesis development of higher power photonic microwave using wide bandgap photoconductors are also discussed.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.51472266,51202286,and 91422303)the Strategic Priority Research Program(B)of the Chinese Academy of Sciences(Grant No.XDB07020100)the ICDD
文摘A new layered Cu-based oxychalcogenide Ba_3Fe_2O_5Cu_2S_2 has been synthesized and its magnetic and electronic properties were revealed. Ba_3Fe_2O_5Cu_2S_2 is built up by alternatively stacking [Cu_2S_2]^（2-） layers and iron perovskite oxide[（FeO_2）（BaO）（FeO_2）]^（2-）layers along the c axis that are separated by barium ions with Fe^（3＋） fivefold coordinated by a square-pyramidal arrangement of oxygen. From the bond valence arguments, we inferred that in layered CuC h-based（Ch =S, Se, Te） compounds the ＋3 cation in perovskite oxide sheet prefers a square pyramidal site, while the lower valence cation prefers the square planar sites. The studies on susceptibility, transport, and optical reflectivity indicate that Ba_3Fe_2O_5Cu_2S_2 is an antiferromagnetic semiconductor with a Ne′el temperature of 121 K and an optical bandgap of 1.03 eV. The measurement of heat capacity from 10 K to room temperature shows no anomaly at 121 K. The Debye temperature is determined to be 113 K. Theoretical calculations indicate that the conduction band minimum is predominantly contributed by O 2p and 3 d states of Fe ions that antiferromagnetically arranged in FeO_2 layers. The Fe 3d states are located at lower energy and result in a narrow bandgap in comparison with that of the isostructural Sr_3Sc_2O_5Cu_2S_2.
基金supported by the Grants-in-Aid for Scientific Research(C)under Grant No.17560295-3620。
文摘TheⅡ-Ⅵbased magnetic semiconductors with a direct and wide optical bandgap are expected to show high potential for optical applications utilizing short wavelength laser diodes(LDs),such as 532-nm green and475-nm blue LDs.We have confirmed that the Faraday rotationθ_F in the ZnMnTe and ZnMnSe films deposited on quartz glass(QG)and sapphire(SA)substrates by using molecular beam epitaxy(MBE)is large near the absorption edge.This paper reports the magneto-optical properties of ZnMnTe and ZnMnSe films synthesized on the QG and SA substrates,and shows the result of a direct Faraday rotation observation successfully made for the ZnMnTe films under 1.28-kHz alternating magnetic fields.The optical absorption characteristics of the ZnMnTe films grown on the SA substrates by MBE are discussed by comparing them with the optical absorption properties and photoluminescence spectra of theⅡ-ⅥZnTe parent single crystals.
基金Project support from the National Natural Science Foundation of China(Grant No.11604254)the Natural Science Foundation of Shaanxi ProvinceChina(Grant No.2019JQ-240)。
文摘Theβ-LiGaO_(2)with an orthorhombic wurtzite-derived structure is a candidate ultrawide direct-bandgap semiconductor.In this work,using the non-adiabatic Allen-Heine-Cardona approach,we investigate the bandgap renormalization arising from electron-phonon coupling.We find a sizable zero-point motion correction of-0.362 eV to the gap atΓ,which is dominated by the contributions of long-wavelength longitudinal optical phonons.The bandgap ofβ-LiGaO_(2)decreases monotonically with increasing temperature.We investigate the optical spectra by comparing the model Bethe-Salpether equation method with the independent-particle approximation.The calculated optical spectra including electron-hole interactions exhibit strong excitonic effects,in qualitative agreement with the experiment.The contributing interband transitions and the binding energy for the excitonic states are analyzed.
基金supported by grants from the National Natural Science Foundation of China(Grant Nos.52102193,52250402,and 61888102)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB30000000)+1 种基金the Fundamental Research Funds for the Central Universitiessupported in part by the Mc Minn Endowment。
文摘The recent successful fabrication of two-dimensional(2D)CoO with nanometer-thickness motivates us to investigate monolayer CoO due to possible magnetic properties induced by Co atoms.Here,we employ first-principles calculations to show that monolayer CoO is a 2D spin-spiral semiconductor with a honeycomb lattice.The calculated phonon dispersion reveals the monolayer's dynamical stability.Monolayer CoO exhibits a type-I spin-spiral magnetic ground state.The spinspiral state and the direct bandgap character are both robust under biaxial compressive strain(-5%)to tensile strain(5%).The bandgap varies only slightly under either compressive or tensile strain up to 5%.These results suggest a potential for applications in spintronic devices and offer a new platform to explore magnetism in the 2D limit.
文摘Power-electronic devices are widely used in various applications, such as voltage and frequency control for transmitting and converting electric power. As these devices are becoming increasingly important, there is a need to reduce their losses and improve their performance to reduce electric power consumption. Current power semiconductor devices, such as inverters, are made of silicon (Si), but the performance of these Si power devices is reaching its limit due to physical properties and energy bandgap. To address this issue, recent developments in wide bandgap (WBG) semiconductor materials, such as silicon carbide (SiC) and gallium nitride (GaN), offer the potential for a new generation of power semiconductor devices that can perform significantly better than silicon-based devices. In this research, a green synthesized copper-zinc-tin-sulfide (CZTS) nanoparticle is proposed as a new WBG semiconductor material that could be used for optical and electronic devices. Its synthesis, consisting of the production methods and materials used, is discussed. The characterization is also discussed, and further research is recommended in the later sections to enable the continual advancement of this technology.
基金funded by the Science,Technology and Innovation Commission of Shenzhen Municipality(Grant no.JCYJ20200109105422876)the Educational Commission of Guangdong Province project(Key program,Grant no.2020ZDZX3041)and the Shenzhen Peacock Plan(Grant no.KQTD2016053112042971).
文摘Over the last few years,great advances have been achieved in exploration of high-mobility two-dimensional(2D)semiconductors such as metal chalcogenide InSe and noble-transition-metal dichal-cogenide PdSe_(2).These materials are competitive candidates for constructing next-generation optoelec-tronic devices owing to their unique crystalline and electronic structures.Moreover,the optical and electronic properties of 2D materials can be efficiently modified via precisely engineering their band structures,which is critical for widening specific applications ranging from high-performance opto-electronics to catalysis and energy harvesting.In this review,we focus on the progress in bandgaps engineering of newly emerging high-mobility 2D semiconductors and their applications in optoelec-tronic devices,incorporating our recent study in the InSe and PdSe_(2)systems.First of all,we discuss the structure-property relationship of typical high-mobility 2D semiconductors(InSe and PdSe 2).Next,we analyze several viable strategies for bandgap engineering,including thickness,strain or pressure,alloying,heterostructure,surface modification,intercalation,and so on.Furthermore,we summarize the optoelectronic devices fabricated with such high-mobility 2D semiconductors.The conclusion and outlook in this topic are finally presented.This review aims to provide valuable insights in bandgap engineering of newly emerging 2D semiconductors and explore their potential in future optoelectronic applications.
