Deep level transient spectroscopy and characterization of deep interface states in polycrystalline zinc oxide

The electronic states present in the bulk and at grain boundary interfaces in semiconductors have a strong influence on the properties of the bulk. The characterization of these states is important for understanding their origins. This thesis addresses the characterization of deep electronic states in the bulk with deep level transient spectroscopy (DLTS) and the characterization of occupied interface states with spectra created from photocapacitance and photoconductance measurements.; The first chapter discusses the methods of data analysis for DLTS established at Alfred. Included in these methods are the use of a square wave filter analysis, Fourier transform analysis, and the method of modulating functions. The analysis of data from Ti doped Si, simulated data, and Ba doped polycrystalline ZnO are included.; The second chapter describes a method for obtaining a density of states spectra from photocapacitance and photoconductance measurements. Using the photocapacitance method on Bi-doped polycrystalline ZnO, two peaks in the density of interface states were observed at depths of 2.49 and 2.79 {dollar}pm{dollar} 0.08eV from the bottom of the conduction band. The two peaks are related to oxygen species adsorbed along the interfaces.; The third chapter discusses the shapes of the transients observed in the photocapacitance measurements and the effects of the illumination intensity on photocapacitance signal used for the density of interface states spectra. The transient shapes support the model of the active states at the interface.