The influence of thermal treatment on Si 1-x Ge x/Si multiple-quantum wells (MQW) p-i-n photodiodes has been investigated by photocurrent spectroscopy combined with X-ray double crystal dif...The influence of thermal treatment on Si 1-x Ge x/Si multiple-quantum wells (MQW) p-i-n photodiodes has been investigated by photocurrent spectroscopy combined with X-ray double crystal diffraction.The cutoff wavelength is significantly reduced due to the Si-Ge interdiffusion and partial relaxation of the strained SiGe alloy.The values of the blue shift increase slowly with the annealing temperatures in the range of 750℃ to 850℃.However,the nonlinear changes in photocurrent intensities of the samples annealed at different temperatures have been observed,which is mainly dominated by the generation of misfit dislocations and the reduction of the point defects in the heating process.展开更多
本文介绍了一款新颖的PRA(Pattern Reconfigurable Antenna)。天线辐射单元主要由三部分组成:包括矩形驱动贴片,两个对称的开了CRS(Cross Ring Slot)的半圆形寄生单元以及地平面。两组p-i-n二极管分别放置在十字形环缝隙上,通过这两组p-...本文介绍了一款新颖的PRA(Pattern Reconfigurable Antenna)。天线辐射单元主要由三部分组成:包括矩形驱动贴片,两个对称的开了CRS(Cross Ring Slot)的半圆形寄生单元以及地平面。两组p-i-n二极管分别放置在十字形环缝隙上,通过这两组p-i-n二极管电开关将它们连接起来,从而可以实现辐射方向图可调。仿真结果表明,天线在4.29GHz^4.87GHz频率范围内S11<-10d B,阻抗带宽大于500MHz,具备良好的宽带特性。并且具有三种辐射方向图,可以通过p-i-n二极管电开关灵活控制,实现方向图可重构特性。展开更多
文摘The influence of thermal treatment on Si 1-x Ge x/Si multiple-quantum wells (MQW) p-i-n photodiodes has been investigated by photocurrent spectroscopy combined with X-ray double crystal diffraction.The cutoff wavelength is significantly reduced due to the Si-Ge interdiffusion and partial relaxation of the strained SiGe alloy.The values of the blue shift increase slowly with the annealing temperatures in the range of 750℃ to 850℃.However,the nonlinear changes in photocurrent intensities of the samples annealed at different temperatures have been observed,which is mainly dominated by the generation of misfit dislocations and the reduction of the point defects in the heating process.
