AVS 58th Annual International Symposium and Exhibition
    Energy Frontiers Focus Topic Tuesday Sessions
       Session EN+NS-TuM

Paper EN+NS-TuM1
Controlled Deposition of Nanocrystal Quantum Dots on Silicon Surfaces: Demonstration and Application of Forster Resonant Energy Transfer

Tuesday, November 1, 2011, 8:00 am, Room 103

Session: Ultrafast Charge and Energy Transfer in Nanomaterials
Presenter: Oliver Seitz, University of Texas at Dallas
Authors: O. Seitz, University of Texas at Dallas
H.M. Nguyen, University of Texas at Dallas
Y.N. Gartstein, University of Texas at Dallas
A.V. Malko, University of Texas at Dallas
Y.J. Chabal, The University of Texas at Dallas
Correspondent: Click to Email
Studying Forster resonant energy transfer (FRET) at semiconductor surfaces has been a challenge because of difficulties in grafting reliably nanocrystal quantum dots (NQDs) onto electronically passivated substrates. Poor control has often resulted in formation of aggregates (3D growth), inhomogeneity, and poor adhesion. In this study, combining IR absorption spectroscopy (IRAS) and X-ray photoelectron spectroscopy (XPS), photoluminescence, atomic force microscopy (AFM) and electrical measurements, we have grafted self-assembled monolayers (SAMs) on both oxidized and oxide-free silicon surfaces with appropriate functionality to obtain dense monolayer of NQDs and to study FRET. SAMs that are directly attached to the silicon via Si-C bonds display a high interface quality with a low density of interface states. This makes it possible to prepare systems with tunable thicknesses necessary for FRET investigation. The time evolution of the fluorescence intensity is in good agreement with the predicted thickness dependence. We are currently developing 3D structures to enhance energy collection for a given surface area. Such hybrid colloidal NQD/Silicon optoelectronic structures could potentially be attractive for both photovoltaic as well as light emitting applications.