In this paper, the GaAs sawtooth-doping-superlattice (SDS) collector has been respectively employed in homojunction and heterostructure transistors by molecular beam epitaxy (MBE). For both studied structures, conventional transistor behaviors and the controllable S-shaped negative-differential-resistance (NDR) performance were achieved at room temperature, simultaneously. In the normal-and inverted-mode two-terminal operations, the homojunction transistor exhibited a bi-directional switching phenomenon due to the avalanche multiplications within SDS periods or emitter-base junction depletion region. In addition, for the three-terminal operations, the common-emitter current gain of about 20 and a controllable S-shaped NDR family in larger current regime were obtained when a base current Ib was applied. In this device, the base-controlled sensitivity 5b was up to 8 x 10-3 V/jLtA. On the other hand, the heterostructure transistor was fabricated to improve the frequency response. In comparison with the prior structure, the heterostructure transistor performed similar current-voltage (I-V) characteristics, but a preferable current gain (up to 25) and base-controlled sensitivity 5b (up to 1.6 x 10-1 V/fiA) were obtained.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)