GaN HEMT作为功率、射频器件,是5G通信中核心关键器件。然而,目前其应用可靠性方面仍受到陷阱效应和自热效应的制约。提出了瞬态时间常数谱峰值谱技术的表征技术,有效并定量获取GaN基器件中存在的陷阱及温升构成,主要包括应用瞬态电流...GaN HEMT作为功率、射频器件,是5G通信中核心关键器件。然而,目前其应用可靠性方面仍受到陷阱效应和自热效应的制约。提出了瞬态时间常数谱峰值谱技术的表征技术,有效并定量获取GaN基器件中存在的陷阱及温升构成,主要包括应用瞬态电流法表征器件的深能级陷阱和利用结构函数法提取器件纵向热阻构成的谱值化技术。结合国内外相关研究工作,对这种分析表征手段进行了相关的归纳和总结。给出高达50 V工作电压下HEMT器件的热阻测量结果,对其纵向热阻构成进行了详细地分析。展开更多
The(001) oriented BiFeO_3 thin film was deposited on the Nb: SrTiO_3 substrate by radio frequency magnetron sputtering technology, and the bipolar resistive switching effect was observed in the BiFeO_3/Nb: SrTiO_3 het...The(001) oriented BiFeO_3 thin film was deposited on the Nb: SrTiO_3 substrate by radio frequency magnetron sputtering technology, and the bipolar resistive switching effect was observed in the BiFeO_3/Nb: SrTiO_3 heterostructure. The results showed that the ratio between the high resistance and low resistance was more than two orders at a reading pulse of-0.5 V and it exhibited excellent retention over 3600 s. The current density-voltage characteristic was dominated by the space-charge-limited conduction. The resistive switching effect of the structure was attributed to the trapping/detrapping of the charge carriers.展开更多
Through independent research by the Chinese scientists or their international collaborations,great achievements have been made in interplanetary physics research in China' Mainland during the past two years(2020-2...Through independent research by the Chinese scientists or their international collaborations,great achievements have been made in interplanetary physics research in China' Mainland during the past two years(2020-2022).More than 150 papers have been published in academic journals in this field during this period.These achievements can be grouped into the following areas,at least:(i)solar corona;(ii)solar and interplanetary transient phenomena;(iii)radio bursts;(iv)Magnetohydrodynamic(MHD)numerical modeling;(v)solar energetic particles and cosmic rays.These advances have greatly enriched our understanding of interplanetary physics,i.e.our knowledge of solar activities and solar eruptions,their propagation in the interplanetary space,and the corresponding geoeffects on the Earth.In the sense of application,they have also improved the forecasting of space weather.In this paper we will give a very short review about these advances.展开更多
基金Funded by the National Natural Science Foundation of China(Nos.61201046 and 61306057)the Beijing Natural Science Foundation of China(Nos.4162013,2132023 and 4164082)+2 种基金the Beijing Postdoctoral Research Foundation(No.2015ZZ-33)the Scientific Research Project of Beijing Educational Committee(No.KM201610005005)the Scientific Research Foundation for Returned Overseas Chinese Scholars,State Education Ministry
文摘The(001) oriented BiFeO_3 thin film was deposited on the Nb: SrTiO_3 substrate by radio frequency magnetron sputtering technology, and the bipolar resistive switching effect was observed in the BiFeO_3/Nb: SrTiO_3 heterostructure. The results showed that the ratio between the high resistance and low resistance was more than two orders at a reading pulse of-0.5 V and it exhibited excellent retention over 3600 s. The current density-voltage characteristic was dominated by the space-charge-limited conduction. The resistive switching effect of the structure was attributed to the trapping/detrapping of the charge carriers.
基金Supported by the Strategic Priority Research Program of Chinese Academy of Sciences(XDB 41000000)National Natural Science Foundation of China(41531073,41731067,41861164026,41874202,41474153,42074183 and U1738128)+2 种基金the Youth Innovation Promotion Association of Chinese Academy of Sciences(2016133)Pandeng Program of National Space Science CenterChinese Academy of Sciences。
文摘Through independent research by the Chinese scientists or their international collaborations,great achievements have been made in interplanetary physics research in China' Mainland during the past two years(2020-2022).More than 150 papers have been published in academic journals in this field during this period.These achievements can be grouped into the following areas,at least:(i)solar corona;(ii)solar and interplanetary transient phenomena;(iii)radio bursts;(iv)Magnetohydrodynamic(MHD)numerical modeling;(v)solar energetic particles and cosmic rays.These advances have greatly enriched our understanding of interplanetary physics,i.e.our knowledge of solar activities and solar eruptions,their propagation in the interplanetary space,and the corresponding geoeffects on the Earth.In the sense of application,they have also improved the forecasting of space weather.In this paper we will give a very short review about these advances.
