This dissertation outlines two approaches for improving the efficiency and reducing the cost of photovoltaic energy generation. First, the structures of known binary copper and iron compounds are used to choose the promising compositions Fe₂XS₄ (X = Si, Ge), Cu₃TaQ₄ (Q = Se, Te), and BaCuQ'F (Q' = S, Se,...
Epitaxial LaRh₁/₂Mn₁/₂O₃ thin films have been grown on (001)-oriented LaAlO₃ and SrTiO₃ substrates using pulsed laser deposition. The optimized thin film samples are semiconducting and ferromagnetic with a Curie temperature close to 100 K, a coercive field of 1200 Oe, and a saturation magnetization of 1.7μB per formula unit. The...
The motivation for undertaking this research was to increase the understanding of processing colloidal semiconductor nanocrystals and thin films metallic glasses to enable their wider application in future devices. This research covered two unique materials, lead selenide (PbSe) nanocrystals and thin film metallic glass alloy of zirconium copper aluminum nickel...
Copper sulfides (Cu[subscript x]S) are compound semiconductor materials that exhibit considerable optical and electrical properties varying significantly as a function of the composition. Copper sulfide thin films can be used in many applications, such as solar control coatings, solar cells, photothermal conversion of solar energy, electroconductive coatings, and microwave shielding...
BiCuOSe and SnS are layered, moderate band gap (ε[subscript G] ≈ 1 eV) semiconductors that exhibit intrinsic p type conductivity. Doping of BiCuOSe with Ca results in a slight expansion of the lattice and an increase of the hole concentration from 10¹⁸ cm⁻³ to greater than 10²⁰ cm⁻³. The large...
Solid-state amorphous materials show amazing promise in thin-film electronics. The interface-to-bulk ratio of thin films makes interfacial chemistries of these systems of utmost importance. Thin films of amorphous metals, dielectrics and semiconductors have novel chemistries that are not only based upon their elemental constituent makeup, but also based upon the...
Piezoelectric materials convert mechanical strain into a dielectric displacement, as well as the converse, allowing these materials to be used as sensors, actuators, and transducers. Currently, lead zirconate titanate (PZT) is the primary material used in these applications. Due to environmental toxicity and safety concerns associated with Pb, development of...
Current cadmium telluride and copper indium gallium diselenide thin-film solar cells
(TFSCs) utilize thick absorbers (2 - 4 μm). For efficient carrier extraction in these TFSCs,
the absorber layer requires high carrier mobilities and a long minority carrier lifetime, which
necessitates the use of a high purity, defect-free thin film....