%A Jiang Zhi-Yun (江之韵), Xie Hong-Yun (谢红云), Zhang Liang-Hao (张良浩), Zhang Wan-Rong (张万荣), Hu Rui-Xin (胡瑞心), Huo Wen-Juan (霍文娟) %T Analysis on high speed response of a uni-traveling-carrier double hetero-junction phototransistor %0 Journal Article %D 2015 %J Chin. Phys. B %R 10.1088/1674-1056/24/4/048504 %P 48504-048504 %V 24 %N 4 %U {https://cpb.iphy.ac.cn/CN/abstract/article_117361.shtml} %8 2015-04-05 %X In this paper, the positive influence of a uni-traveling-carrier (UTC) structure to ease the contract between the responsivity and working speed of the InP-based double hetero-junction phototransistor (DHPT) is illustrated in detail. Different results under electrical bias, optical bias or combined electrical and optical bias are analyzed for an excellent UTC-DHPT performance. The results show that when the UTC-DHPT operates at three-terminal (3T) working mode with combined electrical bias and optical bias in base, it keeps a high optical responsivity of 34.72 A/W and the highest optical transition frequency of 120 GHz. The current gain of the 3T UTC-DHPT under 1.55-μm light illuminations reaches 62 dB. This indicates that the combined base electrical bias and optical bias of 3T UTC-DHPT can make sure that the UTC-DHPT provides high optical current gain and high optical transition frequency simultaneously.