摘要
文中理论研究了InP/In0.53Ga0.47As/InP异质结透射式红外光电阴极的时间响应特性，光谱响应范围1.0～1.7μm。在场助偏压的作用下，模拟计算了光激发的电子在阴极内部的传输特性。模拟计算表明，光电阴极的响应速度随场助偏压的增大而加快；随光吸收层厚度的增大而减慢；随光吸收层掺杂浓度的增大，光电阴极的响应速度变慢。发射层厚度及掺杂浓度的增大都会使得阴极的响应时间加长。经过对阴极结构参数和掺杂浓度的优化，得到在吸收层和发射层厚度分别为2μm、0.5μm，掺杂浓度分别为1.5×1015 cm-3、1.0×1016 cm-3时，在适当场助偏压下光电阴极的响应时间可优于100 ps。
The time response characterisitics of InP/In0.53Ga0.47As/InP heterojunction infrared photocathode was studyed in this paper, such photocathode worked at transmission mode with a wide spectral response range from 1.0-1.7 μm. Under certain field-assisted bias voltage, the transmission characteristics of photo-excited electrons inside the phococathode were simulated. The results show that the response speed of the photocathode are accelerated with the increasing of the field-assisted bias voltage. While P-InGaAs photo-absorbing layer is thickened, the response speed gets slow. The response speed also gets slow when increasing the doping concentration of InGaAs photo-absorbing layer. When increasing the thickness and doping concentration of P-InP photoelectron-emitting layer, the respose time will be prolonged. Based on all these conclusions, the structure parameters and doping concentration of each layer were optimized. The optimization results show that when the thickness of the photo-absorbing layer and the photoelectron-emitting layer are about 2μm and 0.5μm respectively, and the doping concentration of photo-absorbing layer and photoelectron-emitting layer are about 1.5 ×1015 cm-3 and 1.0 ×1016 cm-3 respectively, the response time of photocathode can be reduced to less than 100 ps.
出处
《红外与激光工程》
EI
CSCD
北大核心
2013年第12期3163-3167,共5页
Infrared and Laser Engineering
基金
国家自然科学基金(11274377)
