半绝缘GaAs光电导开关的延迟偶极畴工作模式

基于转移电子效应提出半绝缘光电导开关延迟偶极畴工作模式,理论分析了强场下开关的周期性减幅振荡.指出开关的周期性减幅振荡是由于外电路的自激振荡和开关的转移电子振荡共同作用引起的.开关的偏置电场在交流电场的调制下,当畴到达阳极时,开关电场下降到低于耿氏阈值电场ET而高于维持电场ES(维持畴生存所需的最小电场),开关将工作于延迟偶极畴模式.进而从理论和实验两方面指出半绝缘GaAs光电导开关是一种光注入畴器件,光生载流子的产生使得载流子浓度与器件长度乘积满足产生空间电荷畴所需的条件.

Delayed-Dipole Domain Mode of Semi-Insulating GaAs Photoconductive Semiconductor Switches

A mode for the periodicity and weakening surge in semi-insulating GaAs photoconductive semiconductor switches is proposed based on the transferred-electron effect.It is shown that the periodicity and weakening surge is caused by the interaction between the self-excitation of the resonant circuit and transferred electron oscillation of the switch.The bias electric field (larger than Gunn threshold) across the switch is modulated by the AC electric field,when the instantaneous bias electric field E is swinging below Gunn electric field threshold ET but greater than the sustaining field ES (the minimum electric field required to support the domain) at the time of the domain reaching the anode,and then the delayed-dipole domain mode of switch is obtained.It is the photon-activated carriers that satisfy the requirement of charge domain formation on carrier concentration and device length product of 1012cm-2,and the semi-insulating GaAs photoconductive semiconductor switch is essentially a type of photon-activated charge domain device.