A nanostructured cavity based transmissive structural color device

Abstract

The utility model provides a kind of transmission structural color device based on nanostructure cavity, it is composed of substrate layer, nanostructure cavity and top layer high refractive index dielectric layer.Nanostructure cavity is composed of lower metal layer, upper metal layer and the low refractive index intermediate dielectric layer including high refractive index dielectric square array.The thickness h2 of lower metal layer is 25nm, the thickness h3 range of upper metal layer is 25-55nm, the thickness h4 of high refractive index dielectric square array is 192nm, the thickness h5 of low refractive index intermediate dielectric layer is 240nm, the thickness h6 of top layer high refractive index dielectric layer 6 is 50nm, the width w range of high refractive index dielectric square array is 30-150nm, period P is 160nm.The utility model can obtain angle-insensitive, high saturation and transmission color with large color gamut coverage range by adjusting the width of high refractive index dielectric square array under the condition of keeping the thickness of upper metal layer unchanged.

Description

Technical Field

[0001] This utility model relates to the field of micro-nano optics, specifically to a transmission structured color device based on a nanostructured cavity. Background Technology

[0002] Biomimetic structural colors based on metal surfaces are considered to possess characteristics such as high-quality full-color display, high angular tolerance, flexible polarization control, and low loss, making them crucial for optical applications in advanced information encryption, display, and filtering technologies. Due to the excellent performance of structural colors, the color characteristics (such as hue, saturation, and brightness) of structural color devices (especially those based on Fabry-Perot resonators (FP cavities)) have been extensively studied.

[0003] Currently, the shortcomings of FP-cavity-based structured color devices mainly lie in two aspects: 1) FP-cavity-based structured color devices cannot simultaneously achieve good angle insensitivity and wide color gamut coverage; that is, there is always a trade-off between angle insensitivity and color gamut coverage; 2) Traditional FP-cavity-based structured color devices control color by adjusting the thickness of the intermediate dielectric layer, which is not conducive to the realization of monolithically integrated full-color displays. Therefore, if FP-cavity-based structured color devices can simultaneously achieve good angle insensitivity and wide color gamut coverage, while also meeting the requirements for monolithically integrated full-color displays, it will promote the application of FP-cavity-based structured color devices in advanced display fields such as photography and dynamic color rendering. Utility Model Content

[0004] To address the shortcomings of existing technologies, this invention proposes a transmissive structural color device based on a nanostructure cavity. This device can achieve angle-insensitive, wide color gamut, and high-saturation transmissive structural colors, while also having adjustable color brightness and monolithic integration characteristics.

[0005] The technical solution of this utility model:

[0006] A transmissive structured color device based on a nanostructured cavity is formed by stacking a substrate layer, a nanostructured cavity, and a top high-refractive-index dielectric layer from bottom to top. The nanostructured cavity consists of a lower metal layer, an upper metal layer, a high-refractive-index dielectric block array, and a low-refractive-index intermediate dielectric layer. The high-refractive-index dielectric block array is embedded in the low-refractive-index intermediate dielectric layer to form a nanostructured intermediate layer.

[0007] Furthermore, the substrate layer is made of silicon dioxide, and the upper and lower metal layers are made of silver. The thickness h2 of the lower metal layer is 25 nm, and the thickness h3 of the upper metal layer ranges from 25 to 55 nm. By increasing the thickness of the upper metal layer, some light is absorbed and reflected, thereby adjusting the brightness of the transmitted color.

[0008] Furthermore, the high-refractive-index dielectric block array is made of either titanium dioxide or zinc sulfide, with a thickness h4 of 192 nm, a period P of 160 nm, and a width w of 30-150 nm. The low-refractive-index intermediate dielectric layer is made of either dimethylpolysiloxane, polyvinyl alcohol, or polyimide, with a thickness h5 of 240 nm. Embedding high-refractive-index dielectric block arrays of different widths into the low-refractive-index intermediate dielectric layer allows for the control of the equivalent refractive index of the nanostructure intermediate layer, thereby realizing a monolithically integrated full-color structural color device.

[0009] Furthermore, the top high-refractive-index dielectric layer is made of either titanium dioxide or zinc sulfide, and its thickness h6 is 50 nm. This top high-refractive-index dielectric layer acts as an anti-reflection layer in the device.

[0010] In the above technical solution, embedding the high refractive index dielectric block array at any position in the low refractive index intermediate dielectric layer will not affect the control of the equivalent refractive index of the nanostructure intermediate layer of the nanostructure cavity; under this premise, the width of the high refractive index dielectric block array can still be adjusted to realize a monolithically integrated full-color structured color device.

[0011] Compared with the prior art, the advantages and positive effects of this utility model are:

[0012] 1. This invention employs a nanostructured cavity structure, enabling the integration of various transmitted colors on the same cavity length and substrate. By controlling the width of the high-refractive-index dielectric block array, the refractive index of the nanostructured intermediate layer of the nanostructured cavity can be controlled. In other words, by controlling the refractive index of the intermediate dielectric layer of the FP cavity, a wide range of transmitted colors can be controlled, achieving transmitted colors covering approximately 130% of the sRGB color gamut and approximately 90% of the Adobe sRGB color gamut.

[0013] 2. Based on the cavity resonance effect, the field of view of the transmissive color display of this invention is not less than 25°; by adjusting the thickness of the upper metal layer, this invention can also provide customized brightness for the transmissive color to meet application requirements. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of a transmission structured color device based on a nanostructured cavity;

[0015] Figure 2 This invention relates to the transmission spectrum and color characteristics of high refractive index medium block arrays of different widths.

[0016] Figure 3This invention features angle insensitivity under high refractive index medium block arrays of different widths;

[0017] Figure 4 This invention relates to the transmission spectrum and color characteristics of the upper metal layer under different thicknesses.

[0018] Figure 5 This is a cross-sectional schematic diagram of a transmission structured color device based on a nanostructured cavity; Detailed Implementation

[0019] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. However, the embodiments are not intended to limit the present invention. Any similar structures and similar variations of the present invention should be included in the protection scope of the present invention.

[0020] This invention includes a transmissive structured color device based on a nanostructured cavity. Specific parameters of the embodiment are as follows: This invention is constructed by stacking a substrate layer 1 made of silicon dioxide, a nanostructured cavity, and a top high-refractive-index dielectric layer 6 with a thickness h6 of 50 nm made of titanium dioxide, sequentially from bottom to top. Figure 1 As shown, the nanostructure cavity consists of a lower metal layer 2 with a thickness h2 of 25 nm and made of silver, an upper metal layer 3 of suitable thickness and made of silver, a high-refractive-index dielectric block array 4 with a thickness h4 of 192 nm and made of either titanium dioxide or zinc sulfide, and a low-refractive-index dielectric layer 5 with a thickness h5 of 240 nm and made of either dimethylpolysiloxane, polyvinyl alcohol, or polyimide. The high-refractive-index dielectric block array 4 is embedded within the low-refractive-index dielectric layer 5 to form the intermediate layer of the nanostructure. The thickness h3 of the upper metal layer 3 ranges from 25 to 55 nm, the width w of the high-refractive-index dielectric block array 4 ranges from 30 to 150 nm, and the period P of the high-refractive-index dielectric block array 4 is 160 nm.

[0021] The specific steps of the fabrication method of the transmission structured color device based on the nanostructured cavity of this invention are as follows:

[0022] Step 1: A 25nm thick silver layer is deposited on a substrate layer 1 made of silicon dioxide using electron beam evaporation technology. The silver layer is the lower metal layer 2.

[0023] Step 2: Spin-coat one of the following materials, namely dimethylpolysiloxane, polyvinyl alcohol, and polyimide, on the upper metal layer 2 and cure it to form a low refractive index thin film layer. Then, etch the thin film layer to a thickness of 24 nm by reactive ion etching.

[0024] Step 3: Deposit a 192 nm thick layer of either titanium dioxide or zinc sulfide on the basis of the low refractive index thin film layer in Step 2 using plasma-enhanced chemical vapor deposition to form a high refractive index non-destructive dielectric layer.

[0025] Step 4: Spin-coat an electron beam photoresist film on a high refractive index non-destructive dielectric layer and dry it to form an electron beam photoresist layer; fabricate a block array on the electron beam photoresist layer.

[0026] Step 5: Focused ion etching of the block array in Step 4 to obtain a high refractive index dielectric block array 4;

[0027] Step 6: Spin-coat one of the following materials—dimethylpolysiloxane, polyvinyl alcohol, or polyimide—on the high-refractive-index dielectric block array 4 and cure it to form a low-refractive-index thin film layer. Then, etch the low-refractive-index thin film layer to 24 nm using reactive ion etching. Finally, a low-refractive-index intermediate dielectric layer 5 with a thickness of 240 nm is formed, which encapsulates the high-refractive-index dielectric block array 4.

[0028] Step 7: Deposit an upper metal layer 3 of silver on the low refractive index intermediate dielectric layer 5 using electron beam evaporation technology, and deposit a layer of 50 nm thick material, either titanium dioxide or zinc sulfide, on the upper metal layer 3 by plasma-enhanced chemical vapor deposition to form the top high refractive index dielectric layer 6.

[0029] This is how we obtain... Figure 1 The structure of the transmissive structural color device is shown.

[0030] Figure 2 This invention presents the transmission spectrum and color characteristics of high-refractive-index dielectric block arrays 4 with different widths. In this case, the thickness of the upper metal layer 3 is 25 nm. For example... Figure 2 As shown in (a), as the width of the high-refractive-index dielectric block array 4 increases from 30 nm to 150 nm, the main transmission peak (wavelength) of the transmission spectrum redshifts from 441 nm to 618 nm. Simultaneously, the transmission efficiency of the main transmission peak can be maintained above 70% under different widths of the high-refractive-index dielectric block array 4, and the full width at half maximum (FWHM) of the main transmission peak can be maintained below 30 nm. Figure 2 As shown in (b), the color gamut corresponding to the transmission spectrum of the high refractive index dielectric block array 4 with different widths of this invention can cover approximately 130% of the sRGB color gamut and 90% of the Adobe sRGB color gamut, as shown in 2(c). That is, by adjusting the width of the high refractive index dielectric block array 4, the effective refractive index of the nanostructure intermediate layer can be controlled, thereby achieving full color gamut and high saturation transmission structural color.

[0031] Figure 3 This invention demonstrates the angle-insensitive characteristic of high-refractive-index dielectric block arrays 4 with varying widths. In this case, the thickness of the upper metal layer 3 is 25 nm. Clearly, the transmission structured color devices with high-refractive-index dielectric block arrays 4 of different widths exhibit transmission spectra at different incident angles. From... Figure 3 It can also be observed that within the incident angle range of 0°-25°, the peak transmittance (T) and resonant wavelength of the transmissive structured color device with different widths of high-refractive-index dielectric block array 4 remain essentially unchanged; specifically, the changes in peak transmittance and relative resonant wavelength shift of the transmissive structured color device with different widths of high-refractive-index dielectric block array 4 are less than 1.4% and 1.6%, respectively. These facts corroborate that the proposed transmissive structured color device can achieve a wide field of view of up to 25°.

[0032] In addition to achieving high-quality transmissive color that is insensitive to angle (i.e., control over color chromaticity), this invention also proposes a scheme for adjustable color brightness, such as... Figure 4 As shown, a transmissive structured color device with a 100nm wide high-refractive-index dielectric block array 4 is selected as an example to study its transmission spectrum and color characteristics under upper metal layer 3 with different thicknesses. Clearly, as the thickness of the upper metal layer 3 increases from 25nm to 55nm, the resonant wavelength of the 100nm wide high-refractive-index dielectric block array 4 remains essentially unchanged, but its peak transmission efficiency gradually decreases. Correspondingly, the chromaticity and saturation of the transmitted color remain essentially unchanged with respect to the change in the transmission spectrum, but the brightness of the transmitted color gradually decreases. That is, by simply changing the thickness of the upper metal layer 3, a full-color display with customized brightness can be obtained.

[0033] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0034] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A transmissive structural color device based on a nanostructured cavity, characterized in that: It is composed of a base layer, a nanostructure cavity, and a top high-refractive-index medium layer stacked from bottom to top; the nanostructure cavity is composed of a lower metal layer, an upper metal layer, a high-refractive-index medium block array, and a low-refractive-index intermediate medium layer; the high-refractive-index medium block array is embedded in the low-refractive-index intermediate medium layer to form a nanostructure intermediate layer.

2. The transmissive structural color device based on a nanostructured cavity according to claim 1, characterized in that: The base layer is made of silicon dioxide.

3. The transmissive structural color device based on a nanostructured cavity according to claim 1, characterized in that: The upper metal layer and the lower metal layer are made of silver.

4. The transmissive structural color device based on a nanostructured cavity according to claim 1, characterized in that: The high refractive index dielectric block array and the top high refractive index dielectric layer are made of either titanium dioxide or zinc sulfide.

5. The transmissive structural color device based on a nanostructured cavity according to claim 1, characterized in that: The material of the low-refractive-index intermediate dielectric layer is one of dimethylpolysiloxane, polyvinyl alcohol, or polyimide.

6. The transmissive structural color device based on a nanostructured cavity according to claim 1, characterized in that: The thickness h2 of the lower metal layer is 25 nm; the thickness h3 of the upper metal layer ranges from 25 to 55 nm.

7. The transmissive structural color device based on a nanostructured cavity according to claim 1, characterized in that: The thickness h4 of the high refractive index dielectric block array is 192 nm, the width w of the high refractive index dielectric block array is 30-150 nm, and the period P of the high refractive index dielectric block array is 160 nm.

8. The transmissive structural color device based on a nanostructured cavity according to claim 1, characterized in that: The thickness h5 of the low-refractive-index intermediate medium layer is 240 nm.

9. The transmissive structural color device based on a nanostructured cavity according to claim 1, characterized in that: The thickness h6 of the top high-refractive-index dielectric layer is 50 nm.

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