Modulation of high current gain $(β>49)$ light-emitting $InGaN∕GaN$ heterojunction bipolar transistors

The electrical and optical characteristics of high-gain, small-area $InGaN∕GaN$ heterojunction bipolar transistors (HBTs) grown by metal-organic chemical vapor deposition on sapphire substrate are reported. The common-emitter current-voltage characteristics of a $3×10μm2$ emitter device demonstrates a current gain $β=ΔIC∕ΔIB=49$ at $3mA$ and breakdown voltage, $BVCEO>70V$⁠. The radiative recombination spectrum of a large area $100×100μm2$ emitter HBT is measured, showing a peak at $387nm$ and a full width at half maximum of $47nm$⁠. A $1kHz$ modulation input is applied to the HBT and both the optical and electrical outputs of a large area device is demonstrated.