The present invention is related to a hot-electron photo transistor. By applying the combination of quantum dots or quantum wires with sizes, the wide spacer layers, and the blocking layers to the electron injecting barrier of the emitter, the wide range of infrared detection can be attained and the resolution of detected infrared wavelength can be increased. And by introducing the resonant tunneling quantum well structure to the base layer the selection, amplification and processing of the specific infrared frequency is possible and the reduction of the dark current is induced. Therefore, the present invention is applicable to ultra-high speed tunable infrared detectors and amplifiers, ultra-high speed switching and logic devices, high speed infrared logic devices with new features, new high-speed infrared logic devices which can reduce the number of logic devices.