In this paper we report, for the first time, the large current gain of the metal base transistor using Bi(Ba, Rb)O, and oxide semiconductors. I-V curves of a Bi(Ba, Rb)O, base transistor in common-base configuration were studied from room temperature to 30 K. Current gain (Y -1 was obtained at 50 K. Transport behavior was discussed by analysis of threshold voltages and derivatives dIc / dV,,.

The electron motions in the beat wave composed of two strong Gaussian laser beams in vacuum are numerically studied with special attention paid to the finite-diameter effects. It is shown that electrons can be strongly accelerated, if they are appropriately injected into the beat wave. The acceleration gradients are obtained for the various values of the laser amplitude. These results are discussed on the basis of the plane wave theory.

The quantum mechanical reflection (QMR) at the interface between the high-Tc superconductor base and the semiconductor collector could be reduced to less than a few percent, if electrons are injected at energies close to the collector barrier. Values of fMAX are possible as high as 270 GHz and 400 GHz for SBHET Si and InAs by reducing the contact resistance of the semiconductor to as low as 10 Omega mu m2. The authors propose the use of ultra-thin metal films as layers to protect Si surfaces from oxidation and interdiffusion. BiSrCaCuO films on the Si(100) substrate covered with an Ag monolayer are deposited by the MBE method in two stages, the first is 1000 AA thick at Tsub=530 degrees C and the next 3000 AA thick at Tsub=700 degrees C, which showed the superconductivity, Tc approximately=20 K. Interdiffusion between the oxide films and Si substrate was hardly observed by AES depth analysis.