Quantum dots (QDs) are a hot topic in optoelectronic device research, due to tailorable absorption and emission properties. Unfortunately, the conventional methods of QD synthesis are hazardous and time-consuming. In this work, we present an alternative method of fabricating cadmium selenide (CdSe) QDs (via rapid microwave synthesis). This novel fabrication method provides a quick and efficient way to synthesize QDs that are almost identical to those commercially available. We also demonstrate the tuning of QD sizes by varying time and temperature during the growth process. Optical spectroscopy was used to measure the emission profile of QDs of various sizes. With ease repeatability, tunability, and scalability, this QD synthesis method can be integrated into a wide range of applications and optoelectronic devices.

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UV-Vis spectroscopy and PL data show that structural incorporation of Eu3+ has an effect on the optical properties of CdSe QDs via energy transfer from host to dopant. This allows for QDs with tunable optical properties via numerous pathways.

The interfacial characteristics and band alignments of high-k ZrO2 on n-GaAs have been investigated by experimentally and density functional theory. We have demonstrated that the frequency dispersion due to interface traps in capacitance-voltage characteristics of ZrO2/GaAs interface was significantly reduced through self-cleaning by trimethylalumina. The experimental valence band offset of 2.10 eV from X-ray photoelectron spectroscopy is found to be lower than that of the calculated value of 3.02 eV. The calculated conduction band offset is 1.21 eV compared to the experimental value of 1.38 eV confirms significant reduction of interface traps due to the Fermi-level pinning minimizing the band misalignment.

The reduction of native oxides on GaAs substrates is studied by short time pulsing of the metal precursor for self-cleaning mechanism using atomic layer deposition (ALD) of Trimethyl aluminum (TMA). The short time pulsing of the TMA is effective for self-cleaning mechanism to reduce the GaAs native oxides. Xray photoelectron studies demonstrated that the pulsed deposition of TMA in the range of 2 to 4s is the most effective way of cleaning the GaAs native oxides. Microscopic studies clearly demonstrate the sharp interface between dielectric/GaAs. GaAs based metal oxide semiconductor (MOS) capacitors were fabricated with ZrO 2 and HfO 2 gate dielectrics using ALD. The effect of growth temperature of dielectric films on GaAs was studied. The as deposited samples have a significant amount of fixed charge in the bulk of the gate dielectric and at dielectric/semiconductor (ZrO 2 or HfO 2 /GaAs) interface, which causes the flat band shift and frequency dispersion.