OPTICAL-DEVICES FROM ALGAAS-GAAS HBTS HEAVILY-DOPED WITH AMPHOTERIC SI

A new optoelectronic multifunctional device, having triple function of light emission, detection and amplification have been developed and s ome preliminary integrated circuits are demonstrated. The devices cons ist of N-p-n or N-P-n AlGaAs-GaAs HBT utilizing amphoteric Si heavily- doped GaAs or AlGaAs p-type base layer. Maximum current gain of 3600, and light output power of about 0.17 mu W with 100 mu A base current ( I-b) in transistor mode operation and of about 10 mu W with I-b = 40 m A in diode mode operation are obtained. The optical emission wave leng ths in both are about 0.85-0.86 mu m. Optical gain of about 130 was ob tained near the 0.86 mu W wavelength as a detection transistor. Spectr um matching between emission and detection wavelength range is achieve d. Some monolithic integrated circuits constituted of the transistors are proposed and demonstrated successfully. The relationship between c urrent gain and radiative quantum efficiency at the transistor operati on is also discussed.