Enhancement of Optical Gain in Floating-Base InGaP–GaAs Heterojunction Phototransistors

Comparative studies on the performances of floating-base InGaP-GaAs heterojunction bipolar phototransistors (HPTs) with and without base contact metal were carried out. Both the fabricated HPTs with base contact metal (HPTs-WB) and without base contact metal (HPTs-WOB) exhibited collector dark current as low as 0.2 pA when they were operated in a floating-base configuration at VCE = 1 V. The HPTs-WOB demonstrated much higher optical gain (120 at an optical power of 1.1 μW irradiated by a 635-nm laser) than the HPTs-WB. The optical gain showed dependency on the illuminating optical power, increasing as the illuminating optical power was increased.

[1]  K. Honjo,et al.  Two-dimensional analysis of surface recombination at the extrinsic base surface under various conditions in {AlGaAs}/{GaAs} heterojunction bipolar transistors , 1995 .

[2]  W. T. Chen,et al.  The influence of base bias on the collector photocurrent for InGaP∕GaAs heterojunction phototransistors , 2005 .

[3]  Alwyn J. Seeds,et al.  Two-terminal edge-coupled InP/InGaAs heterojunction phototransistor optoelectronic mixer , 1997 .

[4]  William Liu,et al.  Fundamentals of III-V Devices: HBTs, MESFETs, and HFETs/HEMTs , 1999 .

[5]  M. Buchanan,et al.  Optical upconverter with integrated heterojunction phototransistor and light-emitting diode , 2006 .

[6]  Jae-Hong Park,et al.  Optical characteristics of InGaP/GaAs HPTs , 2001 .

[8]  S. Chandrasekhar,et al.  High-speed monolithic p-i-n/HBT and HPT/HBT photoreceivers implemented with simple phototransistor structure , 1993, IEEE Photonics Technology Letters.

[9]  S. M. Frimel,et al.  Performance enhancement of GaInP/GaAs heterojunction bipolar phototransistors using dc base bias , 1998 .

[10]  Mohamed Bakry El-Mashade,et al.  Performance analysis and stability testing of a new structure of optoelectronic integrated device , 2004, Microelectron. J..

[11]  Determination of surface recombination velocity s o and carrier lifetime τ o from I F ( V G ) characteristics of Al/PECVD-SiN x /pn-GaAs gated diodes , 2005 .

[12]  D. Wight,et al.  High-gain GaInP/GaAs heterojunction phototransistor utilising guard-ring structure , 1989 .

[13]  C. Caneau,et al.  High-speed Ga0.51In0.49P/GaAs heterojunction phototransistors , 1995 .