We report a novel structure of A1GaN/GaN heterostructure field effect transistors （HFETs） with a Si and Mg pair- doped interlayer grown on Si substrate. By optimizing the doping concentrations of the pair-doped inte...We report a novel structure of A1GaN/GaN heterostructure field effect transistors （HFETs） with a Si and Mg pair- doped interlayer grown on Si substrate. By optimizing the doping concentrations of the pair-doped interlayers, the mobility of 2DEG increases by twice for the conventional structure under 5 K due to the improved crystalline quality of the conduction channel. The proposed HFET shows a four orders lower off-state leakage current, resulting in a much higher on/off ratio （ - 10^9）. Further temperature-dependent performance of Schottky diodes revealed that the inhibition of shallow surface traps in proposed HFETs should be the main reason for the suppression of leakage current.展开更多
分析高速开关阀的占空比一流量特性,针对其流量控制中存在的死区、非线性区及饱和区问题,提出基于占空比线性转换的P W M 控制模型,以实现高速开关阀对平均流量的线性控制.推导占空比线性转换公式,建立占空比线性转换P W M 控制模型,从...分析高速开关阀的占空比一流量特性,针对其流量控制中存在的死区、非线性区及饱和区问题,提出基于占空比线性转换的P W M 控制模型,以实现高速开关阀对平均流量的线性控制.推导占空比线性转换公式,建立占空比线性转换P W M 控制模型,从仿真和实验的角度对比分析高速开关阀在进行占空比线性转换前后对流量的控制特性.研究结果表明：阀口压差一定时,基于占空比线性转换的PWM 控制能够实现高速开关阀在0-100% 占空比范围内对平均流量进行线性控制.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.51177175 and 61274039)the National Basic Research Project of China(Grant Nos.2010CB923200 and 2011CB301903)+4 种基金the Ph.D.Program Foundation of Ministry of Education of China(Grant No.20110171110021)the International Sci.&Tech.Collaboration Program of China(Grant No.2012DFG52260)the National High-tech R&D Program of China(Grant No.2014AA032606)the Science and Technology Plan of Guangdong Province,China(Grant No.2013B010401013)the Opened Fund of the State Key Laboratory on Integrated Optoelectronics(Grant No.IOSKL2014KF17)
文摘We report a novel structure of A1GaN/GaN heterostructure field effect transistors （HFETs） with a Si and Mg pair- doped interlayer grown on Si substrate. By optimizing the doping concentrations of the pair-doped interlayers, the mobility of 2DEG increases by twice for the conventional structure under 5 K due to the improved crystalline quality of the conduction channel. The proposed HFET shows a four orders lower off-state leakage current, resulting in a much higher on/off ratio （ - 10^9）. Further temperature-dependent performance of Schottky diodes revealed that the inhibition of shallow surface traps in proposed HFETs should be the main reason for the suppression of leakage current.
文摘分析高速开关阀的占空比一流量特性,针对其流量控制中存在的死区、非线性区及饱和区问题,提出基于占空比线性转换的P W M 控制模型,以实现高速开关阀对平均流量的线性控制.推导占空比线性转换公式,建立占空比线性转换P W M 控制模型,从仿真和实验的角度对比分析高速开关阀在进行占空比线性转换前后对流量的控制特性.研究结果表明：阀口压差一定时,基于占空比线性转换的PWM 控制能够实现高速开关阀在0-100% 占空比范围内对平均流量进行线性控制.
