Pallab Bhattacharya University of Michigan Ann Arbor
Intellectual Merit: The proposed research program seeks to investigate a novel high-temperature quantum dot detector for the terahertz range of the spectrum. In this device, the transport paths of the dark current and photo current of the device are decoupled with a double-barrier resonant tunneling heterostructure adjoining each quantum dot absorbing layer. The photoexcitation energy in the terahertz is coincident with the tunneling energy of the double barrier heterostructure. As a result, carrier contributing to the photocurrent resonantly tunnel through the double barrier, while the dark current generated by carriers with a broad energy distribution is largely blocked. The device can also be designed for high temperature(= 200K) operations. The proposed terahertz detectors will be designed and realized with InAs/GaAs and InAs/InP self-organized quantum dots. A complete modeling of the device will be complemented by molecular beam epitaxy growth, fabrication and characterization.
Broader Impact: The proposed program will have a broader impact on education and outreach through the inherent multidisciplinary topics (material science, physics, electrical engineering, nanophotonics) and specifically planned efforts. Graduate and undergraduate students participating in the project will participate in interdisciplinary research, preparing these future scientists and engineers for careers in interdisciplinary fields. Specific outreach activities are incorporated in this project aimed at providing undergraduate research opportunities and encouraging elementary school children to pursue science and engineering fields.
