New earth abundant materials for thin film photovoltaics and RF antennas on flexible substrates.

摘要

This dissertation work presents the synthesis and characterization of new earth abundant semiconductor materials which include Iron Pyrite (FeS 2) and Zinc Phosphide (Zn3P2) grown using different deposition techniques for their potential photovoltaic applications. We report synthesis of FeS2 thin films by one-step atmospheric pressure sulfurization of iron oxide films using tert-butyl disulfide (TBDS). The most common sulfur source H2S is also compared with the performance of TBDS. The evolution of pyrite films with sulfurization time and the effect of TBDS and H2S on sulfur diffusion within the film is also presented. The surface along with the bulk chemistry of the synthesized films were investigated in detail using various characterization techniques. Also, a simple and repeatable process for the synthesis Zn3P2 through chemical reflux deposition (CRD) is presented using trioctylphosphine (TOP) as a source of phosphorous. Zn3P2 is grown both in thin film and nanowires form around 350°C and their respective growth mechanisms are discussed. The growth conditions at different temperatures are also studied. The PV response of a CRD grown zinc phosphide is shown.;Additionally, RF patch and mesh antennas compatible for solar integration, vehicular communication and roll to roll manufacturing are designed, fabricated and tested. A polymer free flexible glass from CorningRTM named WillowRTM is used as the substrate for these antennas which enables flexibility. The mesh grid lines and/or transparent conducting oxide layer such as indium tin oxide enables us to have optical transparency. The frequencies at different nodes during the measurement agreed with the simulations in the range of 0-10GHz. Also, transmission measurements are performed to verify the communication between antennas.