The Study On Nanocrystalline Silicon Film For Field Emission Display

The Field emission display (FED),whose imaging principle is very similar to the cathode-ray tube (CRT),not only has a thinner thickness and less energy consume than liquid crystal display (LCD) and plasma display panel (PDP),but also has the preponderances of better luminance, stronger contrast,higher resolution,faster response speed,wider visual angle,and lower cost and electromagnetism radiation.The most significant factor restricting the industrialization of FED,is no perfect cold cathode material,so the study of cathode material attracts a good many researchers'interest. Nanocrystalline silicon (nc-Si) field emission cold cathode is considered as the most promising electronic emitter and a breakthrough in the display device, because it can be compatible to the microelectronic technique as a whole silicon device and will be integrated into the large scale integrate circuit.This paper introduces the research development of several familiar field emission cold cathode material, expatiates the theory of field emission and studies kinds of fabrication processes of nc-Si film. By combination of laser ablated deposition and rapid high temperature anneal, the 400nm-thick nc-Si quantum dots film was fabricated on the n-Si(4-5Ω·cm) substrate. By the instruments of X-ray diffraction, transmission electron microscope,Scanning electron microscope and atom force microscope, we study the nc-Si film and find that the quantum dot arranges tightly and equally, which has a good single crystal structure.It demonstrates the fabrication process is so perfect that we could control the size and distribution of nanocrystalline silicon quantum dots. By testing the field emission character of the nano-silicon cold cathode, we bring forward nc-Si/Si heterogeneity junction diode electronic transmission mechanism and electronic ballistic emitter theory model. At last, The finite element computation program ANSYS is used for the simulation of electric field in nanocrystalline silicon quantum dots film. The relations between the electric field intensity and the radius of quantum dots, the thickness of nanocrystalline silicon film, the dielectric constant of the material covering quantum dots and the size of space between quantum dots are studied. The computation results reveal that when the radius of quantum dots is less than 10nm, the field intensity hardly changes with the radius. The field intensity has an inverse ratio relation with the thickness of nanocrystalline silicon film. The size of space between quantum dots only has a little influence on the tip field intensity. If the relative dielectric constant of the material around quantum dots becomes smaller, the tip field intensity and the periphery field will change in an inverse manner, while the inner field will decrease.