Recent work has shown that plasmonic structures enhance the emitted light of nanoscale semiconductor materials, such as the photoluminescence of colloidal quantum dots (QDs) and MoS2 2D materials. This project will compare the photoluminescence of CdSe colloidal quantum dots and MoS2. A variety of studies will be performed such as photobleaching effects, how photoluminescence relates to lifetime of sample, and polarization studies. In addition, this project will further the understanding of plasmonically enhanced photoluminescence between these semiconductor nanostructures and metal nanostructures. Initial studies will drop cast colloidal metal nanospheres onto quantum dots and MoS2, while future work will fabricate gold structures with electron beam lithography.
This work investigates colloidal, semiconductor Cadmium Selenide (CdSe) QDs with optical spectroscopy measurements. A custom-built microscope has been used for photoluminescence spectroscopy and has collected images, videos, and spectra of samples to study the effects of substrates, sample density, uniformity, and QD aging with time. This set up will be used to detect single to a few molecules, shown by fluorescent intermittency, or QD blinking. Differences in the spectrum will be noted as related to the age of samples, the density of the quantum dots, and the concentration of samples. Further experiments include the potential plasmonic enhancement of QD photoluminescence by gold nanoparticles or nanostructures.