The Preparation And Luminescence Study On Thin Film Phosphor And Thermal Behaviour For Superluminescent Diode

Field Emission Display (FED) is developing owing to its advantages such as wide view angle, high picture quality, low power consumption. It is generally accepted that thin films phosphors have some advantages over bulk-type phosphors such as better thermal stability, better adhesion, and improved uniformity. No general evaluation on traditional CRT luminescent materials was made when they were used in FED by thin film phosphors.Superluminescent diodes (SLDs) take an important role on civil and military use. It should be with high output power, wide spectrum, high Signal-to-Noise and long stability. When running under high current density, the temperature rise come from Joule heating effect in active regions limits SLD output power. The main contributions are as follow:1 Based on the diffraction scattering theory of light and steady-state diffusion of carriers, the numerical model was used as predicting the carrier concentration and CL luminescent intensity changed with film thickness and surface roughness. The model gives a qualitative ways to estimate the luminance properties of thin film phosphors on thickness and roughness of films.2 Y₂O₃:Eu, ZnO:Zn, YAGG:Tb,Gd and ZnS:Zn,Pb thin films with 80-200nm thickness have been grown on ITO substrates by electron beam evaporation, and are annealed under 400℃ and 600℃ respectively. The structure, ingredient, surface morphology properties are studied by XRD, SEM, XPS and PL, CL properties are evaluated. By annealing process, it was found that crystallization is improved and the disfigurement on crystal surface is reformed. The luminescent properties of thin films are enhanced up to 3-10 times with the annealing process.3 The PL and of TL of ZnS:Zn,Pb are studied in detail. The luminescent peak is indicated and energy level by disfigurement is discussed. The results show that blue emission from ZnS:Zn,Pb comes from charge transfer of Pb²⁺ and band transition.4 A 2.1 ×2.lcm² EED prototype which combined by ZnS:Zn,Pb and photoelectric cathode is obtained. The brightness of device is at 34cd/cm² and resolution is at 32 picture elements/cm².5 A SLD with InGaAsP/InP multi-quantum well chips are obtained. The output power of device is at 1mW and peak wavelength and width of spectrum are 1300nm and 28nm respectively. With a two-dimensional heat flow equation, the thermal resistance was calculated for InGaAsP/InP MQWs. The model results match very well with the measured results by pulse excitation at different temperature.