An InGaAsP/InP double-heterojunction bipolar transistor for monolithic integration with a 1.5-µm laser diode

A double-heterostructure InGaAsP/InP bipolar transistor is described which comprises a CdO film as a wide-gap emitter made by sputter deposition. A current gain as high as 40 has been achieved. The transistor could also be operated in an inverted mode with the CdO layer acting as collector. The main feature of this transistor is the structural compatibility with a 1.5-µm DH laser allowing for monolithic integration.