砷化镓光电导开关混合工作模式  

Hybrid Working Mode of the GaAs Photoconductive Semiconductor Switch

作　　者：马湘蓉[1,2] 施卫[1] 向梅[2] 

机构地区：[1]西安理工大学应用物理系,陕西西安710048 [2]新疆师范大学物理与电子工程学院,新疆乌鲁木齐830054

出　　处：《实验室研究与探索》2013年第8期8-12,32,共6页Research and Exploration In Laboratory

基　　金：国家自然科学基金项目(50837005;11204267)

摘　　要：实验中,当偏置电压达到一定阈值时,串联组合(双层)半绝缘(SemiInsulating,SI)砷化镓(GaAs)光电导开关(PCSS)输出为近似方波的双峰脉冲波形。输出脉冲随外加偏置电压的升高,上升时间基本不变,脉宽和下降时间都略有减小,双峰峰值均明显增大,开关呈现出不同于普通单个(单层)开关独特的实验现象。分析认为:串联组合SI GaAs光电导开关和普通单个开关各处于不同的工作模式中,组合开关工作在介于光激发电荷畴(Photoactivated Charge Domain,PACD)和限制空间电荷积累模式(Limit Space charge Accumulation,LSA)(简称限累模式)之间的混合模式,此工作模式使得组合开关中的电场都被扫进阈值之上的负微分迁移率区,抑制了开关进入非线性模式的锁定状态,工作效率较高;而普通开关则工作在光激发电荷畴模式,开关输出电脉冲波形呈现出典型的非线性锁定特性。Double peaks phenomenon of approximate rectangular wave was observed with the biased voltage increasing to a threshold for the cascade combination （double layer） semi-insulating （SI） GaAs photoconductive semiconductor switch （PCSS） in experiment. With the increase of biased voltage, the rise time nearly kept a constant, the width and fall time decreased slightly, and the double peaks increased obviously. The unique experimental phenomenon was continued in the cascade combination PCSS, the transmission characteristics for the combination SI GaAs PCSS were entirely different from the ordinary single （monolayer） switch. The cascade combination and single switch respectively operated in a different mode, the hybrid mode of the combination switch lied in between photoactivated charge domain （PACD） mode and the limit space charge accumulate （LSA） mode, nonlinear mode （which is also called lock-on or high gain mode） was inhibited in the hybrid mode. PACD mode and lock-on effect was displayed typically in the ordinary SI GaAs PCSS.

关 键 词：GAAS光电导开关 光激发电荷畴 限制空间电荷积累模式 混合模式 

分 类 号：TN252[电子电信—物理电子学]