Abstract： Heterojunction phototransistors (HPTs) with several Ge/Si nano-dot layers as the absorption region are fabricated to obtain improved light detectivity at 1.55μm. The HPT detectors are of n-p-n type with ten layers of Ge(8ML)/Si(45nm) incorporated in the base-collector junction and are grown by an ultrahigh-vacuum chemical-vapor-deposition system. The detectors are operated with normal incidence. Because of the good quality of the grown material and fabrication process, the dark current is only 0.71pA/μm2 under 5V bias and the breakdown voltage is over 20V. Compared to the positive-intrinsic-negative (PIN) reference detector with the same absorption layer, the responsivity is improved over 17 times for normal incidence at 1.55μm.
SHI Wen-Hua;MAO Rong-Wei;ZHAO Lei;LUO Li-Ping;WANG Qi-Ming. Fabrication of Ge Nano-Dot Heterojunction Phototransistors for Improved Light Detection at 1.55μm[J]. 中国物理快报, 2006, 23(3): 735-737.
SHI Wen-Hua, MAO Rong-Wei, ZHAO Lei, LUO Li-Ping, WANG Qi-Ming. Fabrication of Ge Nano-Dot Heterojunction Phototransistors for Improved Light Detection at 1.55μm. Chin. Phys. Lett., 2006, 23(3): 735-737.
2006, Vol. 23 
