MOCVD grown InGaP/GaAs multiple negative-differential-resistance (MNDR) resonant-tunneling bipolar transistors

We propose two InGaP/GaAs resonant tunneling bipolar transistors (RTBT's) w ith different superlattice (SL) structures in the emitters. Based on the ca lculations of transmission probability, the ground-state and first excited- state minibands are estimated. The electron transmission through SL structu res is significantly determined by the electric field behaviors across the barriers. The specific designs of barrier width in the SL structures are re sponsible for two electron transport mechanisms of sequential RT conduction associated with the minibands. Experimentally, at higher current levels, t he double- and quaternary-negative difference resistance (NDR) phenomena ar e respectively observed for both devices at 300K. Furthermore, the experime ntal results are in good agreement with the theoretical prediction.