# US 7,609,929 B2 · Surface emitting device and method for fabricating the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,609,929 B2 - Document ID: US7609929B2 - Status: Granted - Kind: B2 - Application number: 11/567,975 - Filed: 2006-12-07 - Published: 2007-10-11 - Granted: 2009-10-27 - Earliest claimed: 2006-04-10 - Assignees: Samsung Electronics Co., Ltd. - Inventors: Kwang Soo Seol; Byoung Ho Cheong; Jae Young Choi; Seong Jae Choi - Web page: https://patentgrep.com/patent/US7609929B2 ## CPC - G02B 6/1225: {comprising photonic band-gap structures or photonic lattices} - B82Y 20/00: Nanooptics, e.g. quantum optics or photonic crystals - H01S 5/183: having only vertical cavities, e.g. vertical cavity surface-emitting lasers [VCSEL] - H01S 3/0941: of a laser diode - H01S 3/169: {Nanoparticles, e.g. doped nanoparticles acting as a gain material} - H01S 5/041: {Optical pumping} - H01S 5/11: Comprising a photonic bandgap structure - H01S 5/3412: {quantum box or quantum dash} - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES - H01S: DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL ## Abstract A surface emitting device using a photonic crystal includes a two-dimensional slab type photonic crystal structure including a first dielectric layer and a second dielectric layer formed on top of the first dielectric layer wherein a plurality of air holes in a two-dimensional lattice pattern are formed on the surface of the second dielectric layer; a light-emitting material layer formed on the inner wall of the air holes; and optical pumping means for irradiating the lateral surface of the photonic crystal structure with light. The surface emitting device shows improved surface emission efficiency and can advantageously emit light close to monochromatic light. Therefore, the surface emitting device can be used to manufacture a surface emitting laser. A method for fabricating the surface emitting device is also disclosed. ## Claims ### Claim 1 A surface emitting device, comprising: a two-dimensional slab type photonic crystal structure including a first dielectric layer and a second dielectric layer having a different dielectric constant than the first dielectric layer and formed on top of the first dielectric layer, wherein a plurality of air holes in a two-dimensional lattice pattern are formed on a surface of the second dielectric layer; a light-emitting material layer formed on an inner wall defining the air holes; and optical pumping means for irradiating a lateral surface of the photonic crystal structure with light. ### Claim 2 (depends on 1) The surface emitting device according to claim 1, wherein the first dielectric layer of the photonic crystal structure has a lower dielectric constant than a dielectric constant of the second dielectric layer. ### Claim 3 (depends on 1) The surface emitting device according to claim 1, wherein a size and geometry of the air holes is adjusted in such a manner that an optical bandgap of the photonic crystal matches an emission wavelength of a material for the light-emitting material layer. ### Claim 4 (depends on 1) The surface emitting device according to claim 1, wherein the air holes formed within the second dielectric layer are arranged in at least one of triangular lattice, a square lattice, a honeycomb, a random pattern, and a combination comprising at least one of the foregoing. ### Claim 5 (depends on 1) The surface emitting device according to claim 1, wherein the first dielectric layer is formed of a material selected from the group consisting of SiO2 ceramic materials, Pyrex glass, quartz glass, and acrylics. ### Claim 6 (depends on 1) The surface emitting device according to claim 1, wherein the first dielectric layer is formed of a material having a relative dielectric constant of 7 or lower. ### Claim 7 (depends on 1) The surface emitting device according to claim 1, wherein the second dielectric layer is formed of a material selected from the group consisting of BaO—Nd2O3—TiO2—B2O3—ZnO2—CuO, Al2O3—TiO2, TiO2, BaO—Bi2O3—Nd2O3—TiO2, BaO—Bi2O3—Nd2O3—TiO2—SrTiO3, BaO—PbO—Nd2O3—TiO2, Ba(Zn, Nb)O3, BaTi4O9, (Zr, Sn)TiO4, Ba(Zn, Ta)O3, Ba(Mg, Ta)O3, and MgTiO3—CaTiO3 ceramic materials. ### Claim 8 (depends on 1) The surface emitting device according to claim 1, wherein the second dielectric layer is formed of a material having a relative dielectric constant of 20 or higher. ### Claim 9 (depends on 1) The surface emitting device according to claim 1, wherein the light-emitting material layer contains quantum dots. ### Claim 10 (depends on 9) The surface emitting device according to claim 9, wherein the quantum dots are selected from the group consisting of quantum dots of Group II-VI compounds, Group II-V compounds, Group III-VI compounds, Group III-V compounds, Group IV-VI compounds, Group I-III-VI compounds, Group II-IV-VI compounds, and Group II-IV-V compounds. ### Claim 11 (depends on 10) The surface emitting device according to claim 10, wherein the quantum dots are selected from the group consisting of CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InP, InAs, InSb, SiC, Fe, Pt, Ni, Co, Al, Ag, Au, Cu, FePt, Fe2O3, Fe3O4, Si, Ge, and a combination comprising at least one of the foregoing materials. ### Claim 12 (depends on 11) The surface emitting device according to claim 11, wherein the quantum dots have a core-shell structure consisting of a core and an overcoating formed on the core, and the overcoating contains at least one material selected from the group consisting of ZnS, ZnSe, ZnTe, CdS, CdSe, CdTe, HgS, HgSe, HgTe, AIN, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, GaSe, InN, InP, InAs, InSb, TlN, TIP, TIAs, TlSb, PbS, PbSe PbTe, and a combination comprising at least one of the foregoing materials. ### Claim 13 (depends on 1) The surface emitting device according to claim 1, wherein the optical pumping means is a light-emitting diode or a laser diode. ### Claim 14 A method for fabricating a surface emitting device, the method comprising: forming a first dielectric layer on a substrate; forming a second dielectric layer on the first dielectric layer; patterning the second dielectric layer forming a patterned photonic crystal structure; coating a polymer electrolyte on the patterned photonic crystal structure forming a polymer electrolyte layer; and coating a light-emitting material on the polymer electrolyte layer forming a light-emitting material layer. ### Claim 15 (depends on 14) The method according to claim 14, wherein the first dielectric layer is formed by a sol-gel process, chemical vapor deposition, or sputtering. ### Claim 16 (depends on 14) The method according to claim 14, wherein the patterning of the photonic crystal structure is performed by e-beam lithography, laser interference lithography, or deep UV photolithography. ### Claim 17 (depends on 14) The method according to claim 14, wherein the patterning the photonic crystal includes: forming a photosensitive film on the first dielectric layer; exposing the photosensitive film to light, followed by developing to obtain a photosensitive film pattern; and chemically etching the photosensitive film using the photosensitive film pattern as a mask to form the photonic crystal pattern. ### Claim 18 (depends on 17) The method according to claim 17, wherein the chemical etching is carried out by wet or dry etching. ### Claim 19 (depends on 14) The method according to claim 14, wherein the polymer electrolyte is selected from positively charged polymer electrolytes, negatively charged polymer electrolytes, and salts thereof. ### Claim 20 (depends on 19) The method according to claim 19, wherein the positively charged polymer electrolytes include polyallylamine and polyethylene imine, and the negatively charged polymer electrolytes include polyacrylic acid and polysulfonic acid. ### Claim 21 (depends on 14) The method according to claim 14, wherein the coating of the light-emitting material is carried out by coating a dispersion of quantum dots using a coating process selected from the group consisting of drop casting, spin coating, dip coating, spray coating, flow coating, screen printing, and ink-jet printing. ### Claim 22 An optoelectronic device comprising an external resonator consisting of a pair of mirrors and a surface emitting device disposed within the external resonator, wherein the surface emitting device comprises; a two-dimensional slab type photonic crystal structure including a first dielectric layer and a second dielectric layer formed on top of the first dielectric layer, wherein a plurality of air holes in a two-dimensional lattice pattern are formed on a surface of the second dielectric layer; a light-emitting material layer formed on an inner wall defining the air holes; and optical pumping means for irradiating a lateral surface of the photonic crystal structure with light. ### Claim 23 (depends on 22) The optoelectronic device according to claim 22, wherein the optoelectronic device is a surface emitting laser. ### Claim 24 (depends on 23) The optoelectronic device according to claim 23, wherein the surface emitting laser further comprises a cutoff filter disposed in a region other than air holes of the surface emitting device. ### Claim 25 (depends on 1) The surface emitting device according to claim 1, wherein the light propagates from the light-emitting material layer in a direction perpendicular to a major plane defining the two-dimensional slab. ### Claim 26 (depends on 1) The surface emitting device according to claim 1, wherein the plurality of air holes are formed only in the second dielectric layer.