Optical Properties And Application Study On One-dimensional Metallodielectric Crystal

The concept of photonic crystal (PC) was first introduced by Yablonovitch and John in 1987, respectively. PC are synthetic micro-structural materials and their refractive index is periodical. The most important characteristic of PC is its photonic band gap, a frequency region for which the propagation of electromagnetic waves is forbidden in certain direction in the structure. So PC has especial ability for inhibiting spontaneous radiation of atoms and controlling light propagation. It will be widely used in the fields of optical communication, microwave communication, integration optical and so on. One-dimensional PC which consists of alternating layers of two dielectric materials is investigated and applied broadly because of its simple theoretical calculation and easy fabrication. When a medium is put into the periodic PC and the structure of PC is destroyed, There will been one or several narrow pass bands appeared in the band gap of PC. These narrow pass bands are called defect modes of PC in academia. The frequency region for which the propagation of electromagnetic waves can transmit in the narrow pass bands. This kind of PC narrow pass band and multi-channel narrow pass band filtering may find applications in super dense wavelength division multiplexing for optical communications and precise optical measurement.The traditional one-dimensional photonic crystal is the dielectric constant of two different periodic arrangement of dielectric material and metal material. If we arrange a periodic dielectric material, electromagnetic wave propagation in it may be modulated by the same way, and performance many special properties: for example, if we put the aluminum block into the air medium, one-dimensional metallic photonic crystal will be formated, and in a narrow frequency range, the reflection rates from 96% to 98%; by inserting Ag layers into the dielectric photonic crystals, we can gain the wider photonic band gap in the whole direction; even in the visible region, by periodic inserting a kind of dielectric materials in, or digging in the surface hole processing, the transmission rate will greatly increase which is not transparent metal originally; metal dielectric photonic crystals for the visible light region of the resonant tunneling effect of incident light can significantly reduce the metal layer on the light absorption, with a small loss, and to choose the polarization of the incident light is not obvious.In the first chapter of this paper, we introduced the basic concepts the sorts,the theoretical investigate ways, the fabrication, the application of PC and the problems which is appeared in investigating PC. And introduced the electroluminescent devices as well as the development of light emitting devices basic principles and common device structure.In the second chapter of this paper, we introduced three ways to calculate photonic crystal transmission & reflection spectrum and band structure: transfer matrix method, plane wave expansion method and finite difference time domain method. We elaborate the transfer matrix method described in detail, and derived the calculation method of metal intercalated photonic crystals and metal dielectric photonic crystal.In the third chapter of this paper, we study by the way that metal intercalation layers are inserted between two medium and metal intercalation layers are inserted in one medium, the influence on photonic crystal band characteristics caused by the metal insert thickness, number of periods, and the location of the intercalation layers in photonic crystals in the case of normal incidence of light. And Ag, Au, Cu, Al were used in the calculation, and the calculation results were compared to identify the situations in different under selection for different systems and the corresponding parameters of metal methods and conclusions. The more important conclusions are outlined below:1. For the first insert mode - the metal layer inserted between two media: the main factors affecting the transmission spectrum there are as the three aspects:(1) Inserted metal thickness. It mainly affects the width of the band and transmission rate, and can add a new band in the specific location.(2) The number of periods of photonic crystals. Like ordinary photonic crystals, with the period number increasing, the transmission rate band edge get smaller, more sharpening and more clear, while the band position does not change. But the difference from ordinary photonic crystals is that the increase in the number of periods also affect the transmission rate - the greater the number of periods is the smaller transmission rate is.(3) Influence on the transmission spectrum of photonic crystals caused by different metal layer inserted. Four different metal intercalation photonic crystal with Ag, Au ,Cu , Al, the band structure of the former three are more similar; with the number of periods or thickness of metal inserted increased, the metal intercalation photonic crystal with Al has the largest change; and short wave edge of the band of Au and Cu gradually become less clear, especially Cu; the band gap of Al is the widest, Ag followed, and the band edge of Ag even better.2. For the second insertion method - a metal inserted in a kind of media: the influence caused by metal intercalation, period number and the properties of metal intercalation is the same as the first insert mode; the other kind of factor that affects transmission spectrum is the position where the metal insert in the dielectric layer.(1) When the metal layer is inserted into the low refractive index medium, with the insertion position from left to right, the band gap widens first and narrows then and there is maximum band gap in the middle of the medium.(2) When the metal layer is inserted into the high refractive index medium, with the insertion position from left to right, the band gap narrows first and widens then and there is minimum band gap in the middle of the medium.(3) By comparing their transmission spectra of the photonic crystal containing Ag, Au, Cu and Al intercalation, we can find that the band gap of the photonic crystal containing Ag intercalation is wider than the one containing Au or Cu, and the transmission rate of the edge is higher and clearer. The transmission spectrum of photonic crystal containing Au is similar as the one containing Cu, and the band transmission rate of short-wave band edge is much lower than the long-wave band edge.The transmission rate of photonic crystal containing Al is the widest, and its period number is the fewest, so it is the economical material.In the fourth chapter of this paper, the research principally focus on the affection of the transmission properties of metallic photonic crystal regarding five physical characteristics such as metal layer thickness, medium thickness, refraction index, metal intercalation, the number of periods.1. The study of photonic crystals' transmission properties with respect to metal layer thickness.With the increasing of the metal layer thickness, the position of the first main transmission peak hardly changes, while other transmission peaks move to the long wavelength side, when the metal thickness is increased gradually, the value of the transmission peaks decreases however the first transmission peak value gain the slowest changing rate. 2. The study of photonic crystals' transmission properties with respect to medium thicknessWhen the medium thickness increases, the main transmission peak will gradually split into two or three peaks, but there is no change with the position of the first main transmission peak. On the other hand, the position of the other peaks move to the red side and the peak number and the wavelength also increase linearly. With the increasing of the medium thickness, the main peak value changes periodically. Whenever the value of the main peak increases to a maximum, it will split into two peaks and create one more peak. Before the third peak appears, the value of the second peak has some fluctuations. However, when the third peak appears, the second peak decreases stably.3. The study of photonic crystals' transmission properties with respect to medium refraction indexWith the increasing of the medium refraction index, the main peak gradually splits and creates the second and third peaks from the edge of the short wavelength side and these transmission peaks' waves move to the red side with a deceleration. So the number and the value of the peak increase gradually and then the values of the peaks turn to the same.4. The study of photonic crystals' transmission properties with respect to different metal intercalationThe main transmission peak positions of four different metal intercalations such as Ag, Au, Cu and Al are separately at the following places as 310nm, 520nm, 570nm and 300nm. The transmission maps of Ag and Au are close to each other. There is a band gap on the short wavelength period of Cu. Due to the largest absorption coefficient Al has the lowest transmission rate. Furthermore, Al has the sharpest peak and shortest half-width in the four different metals. So Al has advantages in making high precision filters.5. The study of photonic crystals' transmission properties with respect to the number of cyclesWhen the position of the first main transmission peak is fixed, whenever there is one more cycle number, there comes a new transmission peak. And the positions of other peaks except the first main peak move to the blue side. With the increasing of the period number, all the transmission peaks' values decrease. But the first main peak decrease larger than the others. The width of the transmission band doesn't have many changes.In the fifth chapter of this paper, we study the characteristics of the top emission organic light emitting devices with Au/(Alq3/Ag)2 anodic. This device only has one Resonance emission peak and emits warm white light in small angle range, which can meet the requirements of the micro-display applications. The maximum efficiency of the device is 12.11cd / A and the Pixel contrast is 63:1, 2.04 times higher than other devices. In addition, by using Au as the electrode, this device can also be compatible with CMOS or OTFT circuit technology and lay a solid foundation for the practical application of the white light top emission.