Pei, Z.Z.PeiShi, J.-W.J.-W.ShiHsu, Y.-M.Y.-M.HsuYuan, F.F.YuanLiang, C.S.C.S.LiangLu, S.C.S.C.LuHsieh, W.Y.W.Y.HsiehTsai, M.-J.M.-J.TsaiCHEE-WEE LIU2018-09-102018-09-10200407413106http://www.scopus.com/inward/record.url?eid=2-s2.0-2442428490&partnerID=MN8TOARShttp://scholars.lib.ntu.edu.tw/handle/123456789/309381https://www.scopus.com/inward/record.uri?eid=2-s2.0-2442428490&doi=10.1109%2fLED.2004.826975&partnerID=40&md5=28e7038fa5896ff489214e844df1fda8In this letter, we create a path to remove excess carriers in the base region of a SiGe phototransistor (HPT) by introducing the trap centers. The behavior of the trap centers in the SiGe heterojunction bipolar transistor (HBT) is a form of nonideal (nkT) base current. The responsivity of the device is ∼0.43 A/W with fully SiGe HBT-compatible device structure to facilitate the integration of the following amplification circuitry. The full-width at half-maximum of the pulse is ∼90 ps and the tail of the optical pulse response is largely reduced with the nkT current. By reducing the tail, bandwidth is increased from 1.5 to 3 GHz. This proposes SiGe HPT is applicable for optoelectronic technology.Bandwidth; Nonideal (nkT) base current; SiGeAmplification; Charge carriers; Electric currents; Electron traps; Heterojunction bipolar transistors; Optoelectronic devices; Semiconducting silicon compounds; Semiconductor device structures; Amplification circuitry; Excess carriers; Integratable phototransistor; Nonideal base current; Phototransistorsletter10.1109/LED.2004.8269752-s2.0-2442428490