Inkjet-printed p-type copper(I) iodide-based TFTs were successfully fabricated. As-printed copper(I) halide semiconductor films, such as CuI, CuBrI, and CuClI, were used as p-type active channel layers for TFTs. The entire process of the TFTs fabrication was maintained under 150 °C, which is compatible with flexible plastic substrates and transparent glass...
In this dissertation, a series of studies in the field of terahertz (THz) science are presented, specifically using nonlinear THz spectroscopy. We exploit huge field enhancement and subwavelength confinement in plasmonic structures. There are three distinct projects which will be discussed: nonlinear THz spectroscopy using plasmonic induced transparency (PIT), THz-triggered...
A new approach to the discovery of high absorbing semiconductors for solar cells was taken by working under a set of design principles and taking a systemic methodology. Three transition metal chalcogenides at varying states of development were evaluated within this framework. Iron pyrite (FeS₂) is well known to demonstrate...
CuInGaSe₂ (CIGS), a promising thin film solar cell material, has gained lots of
attention in decades due to its high energy conversion efficiency and potential lower
manufacture cost over conventional Si solar cells. As a cheaper processing method
compared to vacuum-based techniques, solution-based deposition has been
successfully applied to fabricate...
Over the years, chemical bath deposition (CBD) is being widely used in the fabrication of Cu (In, Ga) Se₂ and CdTe based solar cells and photovoltaics. Many chalcogenides have been successfully deposited by this technique and it has received a great deal of attention owing to its low temperature and...
Current leading thin-film solar cell technologies, i.e., cadmium telluride (CdTe) and copper indium gallium diselenide (CIGS), employ elements which are either toxic (Cd), or rare and/or expensive (In, Te, Ga, and Cd). The aim of this thesis is to investigate new, abundant, non-toxic p-type semiconductors for potential solar absorber application....
In this thesis, I present studies in the field of terahertz (THz) spectroscopy. These studies are divided into three areas: Development of a narrowband THz source, the study of carrier transport in metal thin films, and the exploration of coherent dynamics of quasi-particles in semiconductor nanostructures with both broadband and...
Nanostructured ZnO films were obtained via thermal oxidation of thin films formed with metallic Zn-nanoparticle dispersions. Commercial zinc nanoparticles used for this work were characterized by microscopic and thermal analysis methods to analyze the Zn-ZnO core shell structure, surface morphology and oxidation characteristics. These dispersions were spin-coated on SiO₂/Si substrates...
BaCuChF (Ch = S, Se, Te) materials are chalcogen-based transparent conductors with wide optical band gaps (2.9 – 3.5 eV) and a high concentration of free holes (10¹⁸ – 10²⁰ cm⁻³) caused by the presence of copper vacancies. Chalcogen vacancies compensate copper vacancies in these materials, setting the Fermi level...
The preparation and characterization of thin film oxides and chalcogenides by pulsed laser deposition (PLD) is presented. An overview of fundamental PLD concepts are presented and are followed by a description implementation and development of the PLD systems at OSU. We present the results of thin film growth of high...