tailieunhanh - Báo cáo vật lý: "MODELLING AND SIMULATION STUDY OF VISIBLE EMISSION TRANSMISSIVITY OF SILICON RELATED TO SINGLE AND MULTILAYER ANTIREFLECTION COATINGS"

Tuyển tập các báo cáo nghiên cứu khoa học trên tạp chí khoa học vật lý quốc tế đề tài: MODELLING AND SIMULATION STUDY OF VISIBLE EMISSION TRANSMISSIVITY OF SILICON RELATED TO SINGLE AND MULTILAYER ANTIREFLECTION COATINGS | Journal of Physical Science Vol. 17 2 15-26 2006 15 MODELLING AND SIMULATION STUDY OF VISIBLE EMISSION TRANSMISSIVITY OF SILICON RELATED TO SINGLE AND MULTILAYER ANTIREFLECTION COATINGS Kifah Q. Salih and . Hashim Solid State and Applied Physics Group School of Physics Universiti Sains Malaysia 11800 USM Pulau Pinang Malaysia Corresponding author roslan@ Abstract In this study the effect of single and multilayer thin film coatings at the central wavelength 720 nm on the transmissivity of silicon as active medium has been investigated. A model based on the Transfer Matrix Method TMM of multilayer is used to evaluate the transmittance of Si as active medium emitter at 720-750 nm when Ge SiO2 and Si are used as single and multilayer thin film coatings. The results of this simulation study lead to the following conclusions the transmissivity of 720-750 nm emission of silicon is affected significantly by the single and multilayer thin film coatings of Ge SiO2 and Si SiO2 air and Si Ge Si SiO2 air show high transmissivity of 92 and 100 at 720 nm respectively. Uncoated Si active medium surface shows low transmissivity of 66 . The width of the high-transmittance region of Si Ge Si SiO2 air is less than Si SiO2 air at 720 nm. Keywords antireflection coatings silicon active medium transmissivity 1. INTRODUCTION Crystalline Silicon c-Si is an indirect semiconductor and has little efficiency in light emission. However the optical properties of porous Si p-Si are significantly different from those of bulk c-Si. p-Si is actually a nanocrystalline material. It has dimensions in the low nanometer range. Canham 1 reported that if the structure size reaches a value on the order of 5 nm quantum effects can occur and in fact these effects cause the strong visible PL in the region eV. Nanocrystallite Si has been studied extensively because it would open a new possibility for indirect-gap semiconductors as new materials for optoelectronic applications. The .