Multiple negative differential resistance of InP/InGaAs superlattice-emitter resonant-tunneling bipolar transistor at room temperature

Sequential resonant-tunneling behavior of a resonant-tunneling bipolar transistor with five-period i-InP/n-InGaAs superlattice emitter has been demonstrated. An interesting multiple negative differential resistance (NDR) phenomena resulting from the creation and extension of the high-field domain in a superlattice is observed at room temperature. Furthermore, the employing of a thin n-InGaAs emitter layer between an InP/InGaAs superlattice and p(+)-InGaAs base layer helps to lower the potential spike at the base-emitter junction and the reduce neutral-emitter recombination current. Experimentally, transistor performance, incorporating multiple NDR, with a relatively large current gain of 454 and an offset voltage as low as 80 mV, is achieved. (C) 2003 American Institute of Physics.