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

Abstract

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.