The intent of this proposal is to study and exploit to advantage some of the properties arising from confinement of electron motion to less than three dimensions. The study of confined electron behavior has had tremendous technological impact on all semiconductor devices including transistors, light emitters, and sensors. Our particular focus is on the design, study, fabrication, characterization, and testing of novel optical detectors that use altered regime of conduction due to reduced dimensionality to simultaneously achieve: a) low dark current due to the effect of the electron cloud, b) high responsivity due to the aiding electric field that confines the electron cloud, c) high speed due to reduction of absorption depth and inclusion of a Bragg reflector that forms a resonant cavity structure, and d) wavelength-filtering capability due to Bragg condition. A comprehensive device modeling and simulation with particular stress on the study of transient behavior will be performed. Next generation devices based on different material systems will be constructed and the study of contacts between 3D and 2D will be extended to the case of metallic contacts to 1D wires. In short, we propose a fundamental study of confined electron effects that contributes to the development of a family of novel devices. These devices constitute all the required elements for making a complete high sensitivity optical sensor, be it a near infrared detector for biological imaging or a gigabit Ethernet receiver.
