Modeling and Simulating Optical and Electrical Properties of Novel Quantum Structures.

摘要

The research presented here consists of four parts: in the first part, a novel design of photodetector is proposed where the device is based on QDRTD and conductive polymers. It can detect photons with multiple wavelengths simultaneously by adopting different conductive polymers as the photon absorption region of the device. Its current-voltage characteristics and low frequency noise level is calculated and analyzed. In the second part, the charge transport properties of double strand DNA (dsDNA) contacted between gold film and gold nanoparticles (GNPs) are investigated using the Landauer-type transport model. The I-V characteristics were calculated for the GNP/dsDNA/Au-film system and fitted with the STM experimental results, implying a semiconductor-type transport property of the dsDNA used in the experiment. In the third part, we derived the analytical solution of the dispersion relation and phonon potential for a general case of general case of two-interface wurtzite quantum heterostructures by adopting the Loudon's uniaxial and macroscopic dielectric continuum model. The analytical results were applied to two special cases of SiC/GaN/vacuum and GaN/AlN/Vaccum heterostructures and their implications on the electron-phonon interaction and charge transport in wurtzite quantum heterostructures were discussed there. Lastly, different theoretical approaches were applied to investigate the underlying mechanism of blinking of colloidal QDs due to their limitation on many of the applications of QD-based devices. The results produced by the theoretical models were carefully analyzed and possible causes of QDs blinking were identified. The importance of minimizing the adverse effect of blinking on the design of QD-based devices was also discussed there.