CN101477219A - Liquid crystal display colored color filter with integrated sub-wavelength metal micro-nano structure - Google Patents

Abstract

The invention relates to an integrated subwavelength metal micro-nano structure liquid crystal display color filter, which comprises a substrate slice, wherein the substrate slice is provided with a metal layer, the thickness of the metal layer is 100 to 300nm, the metal layer is provided with periodic pore arrays, and the diameter of the pores is 120 to 200nm. The method relates to the influences of a nanoscale metal array structure on the properties of light. The pore arrays with different periodic constants have filtering effects on light with different colors and wavelengths. Through the design of a reasonable periodical structure, red, green and blue filters can be obtained to meet the requirements of liquid crystal displays on color filters. In the structure, the metal layer is integrated on other flat optical devices, so the miniaturization and integration of the structures of the liquid crystal display are realized.

Description

Liquid crystal display colored color filter with integrated sub-wavelength metal micro-nano structure

Technical field

The present invention relates to an optical element---the colored filter of Thin Film Transistor-LCD (Thin Film Transistor-Liquid CrystalDisplay) back projection light source.

Background technology

The variation why Thin Film Transistor-LCD can produce color mainly is to obtain red, green, blue three coloured light because colored filter (ColorFilter) carries out filtering to the white light source of rear-projection.In the LCD, after the white light that module backlight produces passes through the shaping of some optical modules, evenly, vertical shining on the colored filter, white light can obtain the parallel outgoing of monochromatic light of three kinds of colors of red, green, blue after by colored filter, by liquid crystal light is seen through that control is synthetic to obtain colored display effect at last.The colored filter method for making mainly contains decoration method, pigment dispersing method, print process, electrochemical plating, ink-jet method etc., and the organic material of Red Green Blue is made on the glass substrate.Making the used material of colored filter at present is macromolecular material.The disadvantage of this technology is that the heat resistance of dyestuff or pigment is lower, can not bear too high temperature during work, and this will be a big problem to the display technique of using high lumen.Wherein the color divergence method all takes advantage at aspects such as color characteristics, quality, fiduciary levels, therefore becomes the main flow production method of present colored filter.But these methods are complicated, loaded down with trivial details on production process.The color divergence method need be on substrate operations such as filming repeatedly, photoetching could obtain the array structure of three colors, complicated production run makes that the cost of colored filter is very high, accounts for the significant proportion of whole LCD cost.

Summary of the invention

In order to solve existing colored filter complex manufacturing, problem that manufacturing cost is high, the invention provides a kind of liquid crystal display colored color filter with integrated sub-wavelength metal micro-nano structure.

Studies show that in a large number when light and sub-wavelength metal micro-nano structure interaction, the metal level with sub-wavelength periodicity array of orifices has the optical property of a lot of uniquenesses.In these character, the most significant is that it can have wavelength selection, transmission humidification to the light that sees through.And the cycle of change array of orifices just can be adjusted the maximum centre wavelength that sees through light.This special optical property is because can cause collective's concussion---the surface plasma of metal surface free electron during the metal level of light by having array of orifices periodically.Because the existence of surface plasma, light is more much higher by the light transmission rate of the single aperture of etching on the dielectric layer than light by the transmitance of the single aperture on the metal level; In addition,, have only the light of specific wavelength to interact with surface plasma because periodic array of orifices structure can provide reciprocal lattice vector on the metal level, thus transmitance very high pass through metal level, realization is to through light wavelength selection effect.Utilize the character of this uniqueness, we can be used for making the colored filter in the LCD.

Concrete technical solution is as follows:

Liquid crystal display colored color filter with integrated sub-wavelength metal micro-nano structure comprises substrate slice;

Be provided with a metal level on substrate slice, metal layer thickness is 100-300nm, is provided with to have periodic array of orifices on metal level, and described hole diameter is 120-200nm.

Described metal layer material is a silver or golden.

Described aperture be shaped as circular or square.

The phase constant of described array of orifices is 300nm or 450nm or 580nm.

Because difform aperture is influential through wavelength to the maximum of transmitted spectrum, is example with the circular aperture below, and the filter action of this novel sub-wavelength metal micro-nano structure is described.The realization of colored filter: on the planar metal layer of hundreds of nanometer thickness etching hundreds of nanometer diameter, have the circular aperture array that the periodic square of sub-wavelength is arranged.Obtain the color filter of different wave length by the arrangement cycle size that changes the zones of different circular aperture.The structural parameters in appropriate design aperture cycle and change around medium, can realize the colored filter of three kinds of colors of red, green, blue, realize that the colour of LCD shows.

Have sub-wavelength periodically the metal level of array of orifices structure to have wavelength selectivity by light be owing to must satisfy the momentum matching condition between surface plasma that the metal surface produces and the irradiates light and cause.In LCD, light all be vertical, shine on the colored filter uniformly, under this condition, the relation of the optical wavelength of transmitance maximum and sub-wavelength array of orifices phase constant:

${\mathrm{\λ}}_{\max }=\frac{P}{\sqrt{(i^2+j^2)}}\sqrt{\frac{{\mathrm{\ϵ}}_m{\mathrm{\ϵ}}_d}{{\mathrm{\ϵ}}_m+{\mathrm{\ϵ}}_d}}$

Wherein, λ _MaxBe the optical wavelength of transmitance maximum, P is the phase constant of array of orifices, and i, j are the progression of outgoing diffraction, ε _m, ε _dBe respectively the specific inductive capacity of metal and the specific inductive capacity of metal surrounding medium.

Core of the present invention is to design the periodicity array of orifices on the metal level.Because the method for making of sub-wavelength array of orifices structure is very ripe, just can realize by physical methods such as etching, press molds.

In sum, innovation part of the present invention has been to propose a kind of implementation method of brand-new LCD colored filter.This method is suitable for mutually with common LCD, does not need newly to add optical device and increases cost.Manufacturing process is to realize by physical methods such as very ripe plated film, etching, press molds, does not produce dirty assorted.Because gold or silver-colored chemical stability make device that the very long life-span be arranged.In addition, this method can be plated in metal film on other planar optics elements, reduces the optical device that separates, and can make liquid crystal display device structure integrated.

Description of drawings

Fig. 1 is a structural representation of the present invention,

Fig. 2 is a square aperture array structure synoptic diagram of the present invention.

Fig. 3 is a lighting system synoptic diagram of the present invention,

Fig. 4 is the color filter effect figure of white light after passing through,

Fig. 5 is that the ruddiness of wideband light source of the present invention sees through spectrum,

Fig. 6 is that the green glow of wideband light source of the present invention sees through spectrum,

Fig. 7 is that the blue light of wideband light source of the present invention sees through spectrum.

Embodiment

Below in conjunction with accompanying drawing, the present invention is done to describe further by embodiment.

Embodiment 1:

Referring to Fig. 1, liquid crystal display colored color filter with integrated sub-wavelength metal micro-nano structure comprises substrate slice

Plating one deck thickness h is the 200nm silverskin on substrate slice, and the specific inductive capacity of silver is: ε ₁=-8.498, ε ₂=0.759, the method by focused-ion-beam lithography etches on metal level and has periodic circular aperture array then, and array of orifices is made of the square arrangement circular hole of N * N (the array number is by the size decision of pixel), and hole diameter a is 150nm.

Wavelength according to the Red Green Blue of International Commission on Illumination (CIE) regulation is respectively 700nm, 546.1nm, 435.8nm.The phase constant P that we design the circular aperture array respectively is 300nm, 450nm, 580nm.Like this, the white light source of vertical incidence will obtain transmitance maximum wavelength seeing through about 440nm, 540nm, 720nm and compose, see Fig. 3, Fig. 5, Fig. 6 and Fig. 7, so just can under the situation of vertical incidence light source, realize effect, see Fig. 4 the three primary colors pseudo-colour filtering.

Embodiment 2:

On metal level, etch and have periodic square aperture array, see Fig. 2, design suitable parameter, also can obtain the colored filter of different wave length.

Other is with embodiment 1.

Claims (4)

1, liquid crystal display colored color filter with integrated sub-wavelength metal micro-nano structure comprises substrate slice, it is characterized in that:

Be provided with a metal level on substrate slice, metal layer thickness is 100-300nm, is provided with to have periodic array of orifices on metal level, and described hole diameter is 120-200nm.

2, liquid crystal display colored color filter with integrated sub-wavelength metal micro-nano structure according to claim 1 is characterized in that: described metal layer material is silver or golden.

3, liquid crystal display colored color filter with integrated sub-wavelength metal micro-nano structure according to claim 1 is characterized in that: described aperture be shaped as circular or square.

4, liquid crystal display colored color filter with integrated sub-wavelength metal micro-nano structure according to claim 1 is characterized in that: the phase constant of described array of orifices is 300nm or 450nm or 580nm.

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