Publications [#66849] of Adrienne D. Stiff-Roberts

Papers Published

1. Stiff-Roberts, Adrienne D. and Gupta, Abhishek and Zhao, Zhiya, Optical characterization of CdSe colloidal quantum dot/ MEH-PPV polymer nanocomposites spin-cast on GaAs substrates, Materials Research Society Symposium Proceedings, vol. 939 (2006), pp. 8 - 13, San Francisco, CA, United States
   (last updated on 2007/04/16)

   Abstract:
   The motivation and distinct approach for this work is the use of intraband transitions within colloidal quantum dots for the detection of mid- (3-5 μm) and/or long-wave (8-14 μm) infrared light. The CdSe colloidal quantum dot/MEH-PPV conducting polymer nanocomposite material is well-suited for this application due to the [similar to] 1.5 eV difference between the corresponding electron affinities. Therefore, CdSe colloidal quantum dots embedded in MEH-PPV should provide electron quantum confinement such that intraband transitions can occur in the conduction band. Further, it is desirable to deposit these nanocomposites on semiconductor substrates to enable charge transfer of photogenerated electron-hole pairs from the substrate to the nanocomposite. In this way, optoelectronic devices analogous to those achieved using Stranski-Krastanow quantum dots grown by epitaxy can be realized. To date, there have been relatively few investigations of colloidal quantum dot nanocomposites deposited on GaAs substrates. However, it is crucial to develop a better understanding of the optical properties of these hybrid material systems if such heterostructures are to be used for optoelectronic devices, such as infrared photodetectors. By depositing the nanocomposites on GaAs substrates featuring different doping characteristics and measuring the corresponding Fourier transform infrared absorbance, the feasibility of these intraband transitions is demonstrated at room temperature. © 2006 Materials Research Society.

   Keywords:
   Cadmium compounds;Fourier transform infrared spectroscopy;Hybrid materials;Infrared detectors;Optoelectronic devices;Quantum confinement;Semiconductor quantum dots;