In this thesis, the fabrication and characterization of various kinds of thin films useful for display applications are discussed. The fabrication technique used was mainly pulsed laser deposition, sputtering was also used to fabricate ITO films on glass....[ Read more ]

In this thesis, the fabrication and characterization of various kinds of thin films useful for display applications are discussed. The fabrication technique used was mainly pulsed laser deposition, sputtering was also used to fabricate ITO films on glass.

In-situ resistance measurement was used to characterize the initial growth of ITO thin films on glass. It was found that at a growth temperature of 150℃ or above, ITO grows via a 2D layer by layer growth mechanism with a conductive critical thickness of about one lattice constant. With the growth temperature of less than 150℃, the films grow via a 3D growth mode. The growth mode transition also coincides with the amorphous to poly transition. ITO films with ultra-thin thickness were fabricated by pulsed laser deposition on various kinds of substrates; very good crystalline quality ITO films on YSZ, highly textured ITO films on ZnO buffered glass, poly-crystalline ITO films on glass. ZnO turns out to be a good buffer layer to grow textured ITO films on glass. Then sputtering was adopted to grow ITO films with a thin ZnO buffer layer. The ITO films with improved crystal and electrical properties were obtained.

GaN is presently the hottest material being studied as a photonic material emitting in blue and UV. Blue LEDs and LDs based on GaN, and its related group-III nitride (InN and AlN), have been successfully fabricated by MOCVD. In this thesis, a novel pulsed laser deposition technique called liquid target pulsed laser deposition was reported. It was used to fabricate GaN thin films from a gallium liquid. Liquid target pulsed laser deposition, to a certain extent, overcomes the target deterioration, target rotation, and splashing problems compared to traditional solid target pulsed laser deposition. Reasonably good crystal quality GaN thin films were fabricated on various substrates of quartz, silicon, and sapphire with a thin layer of ZnO buffer. Epitaxially grown GaN films were fabricated on ZnO buffered sapphire at an elevated substrate temperature.

Since ZnO, a transparent conducting oxide and a lasing material, turns out to be a good buffer layer for both GaN and ITO. We studied the optical properties of epitaxially grown ZnO thin film on sapphire by photoluminescence measurement and variable angle spectroscopic ellipsometry. The bandgap, at room temperature and at lOK, and the refractive index of ZnO on sapphire were obtained. These data should be useful for the designs of GaN-based LEDs and LDs using ZnO as a buffer layer and, ZnO-based light emitting devices as an active layer.

Phosphor thin film is an important topic in display application for color representation. In this thesis, we report the fabrication of red, green and blue primary color silicate phosphor thin films on silicon and silicon dioxide covered silicon substrates by pulsed laser deposition. By annealing at 800℃-l000℃, reasonably good purity red, green and blue photoluminescence were obtained. Electric field induced photoluminescence quenching experiments were performed on manganese-doped zinc silicate green phosphor. These silicate phosphor thin films may have applications in low voltage cathodoluminescence for field emission displays and electroluminescence displays.