The theme of this thesis is MBE growth of high resistivity semiconductor epi-layers and MBD growth of silicon oxide anti-reflection films. For MBE growth of high resistivity semiconductor epi-layers, In0.523Al0.477As and In0.527Al0.228Ga0.245As lattice matched to InP and grown by MBE at 400¢J has been investigated. We construct n-i-n and p-i-n structure diode models to evidence that the nonlinear I-V characteristics are an intrinsic property of 400¢J In0.523Al0.477As and In0.527Al0.228Ga0.245As, and not due to barriers to current injection at the n+ InGaAs/ high resistivity epi-layer and high resistivity epi-layer/n+ InP heterojunctions. We obtained the effective resistivities of 400¢J In0.523Al0.477As and In0.527Al0.228Ga0.245As at 7V are still more than 109 £[ cm and 107 £[ cm, respectively, in n-i-n structure. They are more than sufficient for most practical applications. For MBD growth of silicon oxide anti-reflection films, we have set up the SiO MBD system in our lab. Then we measured the index of the SiO film that we deposited in the wavelength of 1550nm is about 1.85. Finally, we coated SiO anti-reflection film on one cleaved facet of a Fabry-Perot laser. The reflectance R of the coated facet is reduced to about 1.7¡Ñ10-4 in the vicinity of £f¡×1580 nm.

Thin-film theorems are well developed and so are the fabrication processes. Yet under some special conditions, traditional methods (such as the ABCD matrix and the transmission matrix methods) will lead to a serious numerical error. In this thesis, we propose a new method called Couple E/H field formulation, which will overcome this numerical problem in simulating characteristics of complex multi-layered structures. We have verified both the algorithm and its results with the traditional techniques. By extending the impedance matching principle, we came out with a multi-layer anti-reflection coating design optimized for a time-harmonic plane wave incidence with any incident angle. Such a design allows for more plane waves with adjacent angles to pass through the coating layers with minimal reflection. Furthermore, we apply this AR coating design to facets of semiconductor lasers. Our calculation shows that multi-layer coating does a better job than a single layer coating. The reflectivity of a laser diode from single layer coating 0.085% to 5 layer coating 0.056%, which is a 33% improvement.

The purpose of the thesis is to investigate the improvement of single-crystal Si solar cell efficiency using porous Indium tin oxide (ITO)/ITO double layer antireflection(AR) coating. The resistivity, transmittance and refraction index of the porous ITO films prepared by supercritical CO2 treatment were investigated. At a 2000 psi pressure and 60¡CC, the resistivity of porous ITO films is 15 £[-cm, the average transmittance is better than 95 %, and the refraction index is 1.54. In addition, the resistivity of ITO thin films fabricated by reactive ratio-frequency magnetron sputtering is 7¡Ñ10-4 £[-cm, the average transmittance are 85 %, and the refraction index is 2.0. For the single crystal-Si solar cell with porous ITO/ITO double layer AR coating, the open circuit voltage, short circuit current, fill factor and efficiency are measured.