导带不连续性对InGaAsP/InGaAs UTC PD带宽的影响

Impacts of the Conduction Band Discontinuity on Bandwidth of High Speed InGaAsP/InGaAs Uni traveling carrier Photodetector

摘要:

研究了导带不连续性对InGaAsP/InGaAs单行载流子高速光探测器(UTC PD)的3dB带宽的影响。研究结果表明，由于导带不连续性的存在，使得3dB带宽降低。导带不连续性越大，3dB带宽越低。通过增加隧穿系数、收集层厚度、收集层掺杂浓度和减小吸收层掺杂浓度可以在一定程度上消除导带不连续性带来的不利影响。研究结果还表明，增加隧穿系数、收集层厚度和减小吸收层掺杂浓度这三种方法在消除导带不连续性不利影响的同时又有各自的缺点，而适当增加收集层掺杂浓度是最为有效的一种方式。该研究结果可以为UTC PD的设计提供理论指导，特别是采用UTC结构的波导型光电二极管。

Abstract:

The impacts of conduction band discontinuity on 3dB bandwidth of a high speed InGaAsP/ InGaAs uni traveling carrier photodetector were studied. The results show that the 3dB bandwidth is reduced due to the conduction band discontinuity. Greater discontinuity causes more 3dB bandwidth reduction. Increasing tunneling effect, collection layer thickness, doping concentration in the collection layer, and reducing doping concentration in the absorption layer can slow down the 3dB bandwidth reduction to some extent. The study reveals that the three methods also have their own disadvantages. According to the results, appropriately increasing the doping concentration of the collection layer is the most efficient way. The results provide suggestions for designing UTC PDs, especially for waveguide photodiodes with UTC structure.