Intraband Spectroscopy and Dynamics in Semiconductor Nanocrystals Colloids

University Of Chicago, Chicago IL

Investigators

Abstract

Electrons injected in the conduction band of a quantum dot exhibit strong intraband transitions in the mid-infrared and this is interesting for potential applications. This individual investigator award provides support for a project to discern and control the mechanisms that influence the energy, coherence and lifetime of the intraband transitions, in particular the role of phonons and surface states, issues that are currently unclear. The project deals with colloid quantum dots prepared by solution chemistry that allow for the modification of the surfaces. This should provide an important element of control in the electron dynamics. The characterization of the spectroscopy and dynamics of the electrons involves steady state and picosecond time-resolved optical studies using lamp and infrared laser spectrometers. This project, combining wet organometallic chemistry along with extensive charaterization of the nanostructures, offers an excellent opportunity for training graduate students in a frontier area of optical material science. %%% Electrons inside a nanoscopic semiconductor particle are very sensitive to infared radiation and this is interesting for potential applications in the mid-infrared, from lasers to detectors, and night-vision. This individual investigator award provides support for a project to discover and control the mechanisms that influence the infrared response of the electrons. This will be necessary in order to take advantage of the flexibility with which the optical response of the electron can be "engineered" via the size, shape and composition of the nanostructure. Chemistry is used to make the semiconductor particles in solutions. These solutions readily exhibit the effects of quantum mechanics via their strong colors, and they can be processed to make more practical gels or thin films with identical properties. This project combines chemistry and optics of nanomaterials and it offers an excellent opportunity for training graduate students in this technologically promising area of material science. ***