Nitride phosphor and production process thereof, and light emitting device

• US 20060038477A1
• Filed: 10/18/2005
• Published: 02/23/2006
• Est. Priority Date: 03/22/2002
• Status: Active Grant

• Current Assignee: Nichia Corporation
• Original Assignee: Nichia Corporation
• Inventors: Tamaki, Hiroto, Naitou, Takahiro, Murazaki, Yoshinori, Kameshima, Masatoshi, Takashima, Suguru, Sakai, Kazuhiko, Yamada, Motokazu
• Granted Patent: US 7,297,293 B2
• Time in Patent Office: Days
• US Class Current: 313/485
• CPC Class Codes: C01B 21/0602 with two or more other elements chosen from metals, silicon or boron
• CPC Class Codes: C01B 21/0821 Oxynitrides of metals, boron or silicon
• CPC Class Codes: C01P 2002/52 containing elements as dopants
• CPC Class Codes: C01P 2002/84 by UV- or VIS- data
• CPC Class Codes: C01P 2004/03 obtained by SEM
• CPC Class Codes: C01P 2004/61 Micrometer sized, i.e. from 1-100 micrometer
• CPC Class Codes: C04B 2235/3224 Rare earth oxide or oxide forming salts thereof, e.g. scandium oxide
• CPC Class Codes: C04B 2235/3225 Yttrium oxide or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3227 Lanthanum oxide or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3229 Cerium oxides or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3286 Gallium oxides, gallates, indium oxides, indates, thallium oxides, thallates or oxide forming salts thereof, e.g. zinc gallate
• CPC Class Codes: C04B 2235/3852 Nitrides, e.g. oxynitrides, carbonitrides, oxycarbonitrides, lithium nitride, magnesium nitride
• CPC Class Codes: C04B 2235/3873 Silicon nitrides, e.g. silicon carbonitride, silicon oxynitride
• CPC Class Codes: C04B 2235/3895 Non-oxides with a defined oxygen content, e.g. SiOC, TiON
• CPC Class Codes: C04B 2235/764 Garnet structure A3B2(CO4)3
• CPC Class Codes: C04B 35/44 based on aluminates
• CPC Class Codes: C04B 35/584 based on silicon nitride
• CPC Class Codes: C04B 35/597 based on silicon oxynitride, e.g. SIALONS
• CPC Class Codes: C09K 11/0883 Arsenides; Nitrides; Phosphides
• CPC Class Codes: C09K 11/77 containing rare earth metals
• CPC Class Codes: C09K 11/7702 : with zinc or cadmium
• CPC Class Codes: C09K 11/7703 : with alkaline earth metals
• CPC Class Codes: C09K 11/7728 : containing europium
• CPC Class Codes: C09K 11/773 : with zinc or cadmium
• CPC Class Codes: C09K 11/7731 : with alkaline earth metals
• CPC Class Codes: H01L 2224/32245 : the item being metallic
• CPC Class Codes: H01L 2224/45015 : being circular
• CPC Class Codes: H01L 2224/45124 : Aluminium (Al) as principal constituent
• CPC Class Codes: H01L 2224/45139 : Silver (Ag) as principal constituent
• CPC Class Codes: H01L 2224/45144 : Gold (Au) as principal constituent
• CPC Class Codes: H01L 2224/45147 : Copper (Cu) as principal constituent
• CPC Class Codes: H01L 2224/45169 : Platinum (Pt) as principal constituent
• CPC Class Codes: H01L 2224/48091 : Arched
• CPC Class Codes: H01L 2224/48247 : connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48257 : connecting the wire to a die pad of the item
• CPC Class Codes: H01L 2224/48464 : the other connecting portion not on the bonding area also being a ball bond, i.e. ball-to-ball
• CPC Class Codes: H01L 2224/48465 : the other connecting portion not on the bonding area being a wedge bond, i.e. ball-to-wedge, regular stitch
• CPC Class Codes: H01L 2224/49107 : on the semiconductor or solid-state body
• CPC Class Codes: H01L 2224/73265 : Layer and wire connectors
• CPC Class Codes: H01L 2224/8592 : Applying permanent coating, e.g. protective coating
• CPC Class Codes: H01L 2924/00 : Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00012 : Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/00014 : the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/01019 : Potassium [K]
• CPC Class Codes: H01L 2924/01021 : Scandium [Sc]
• CPC Class Codes: H01L 2924/01037 : Rubidium [Rb]
• CPC Class Codes: H01L 2924/01049 : Indium [In]
• CPC Class Codes: H01L 2924/01055 : Cesium [Cs]
• CPC Class Codes: H01L 2924/01066 : Dysprosium [Dy]
• CPC Class Codes: H01L 2924/01067 : Holmium [Ho]
• CPC Class Codes: H01L 2924/01068 : Erbium [Er]
• CPC Class Codes: H01L 2924/01322 : Eutectic Alloys, i.e. obtained by a liquid transforming into two solid phases
• CPC Class Codes: H01L 2924/12041 : LED
• CPC Class Codes: H01L 2924/181 : Encapsulation
• CPC Class Codes: H01L 2924/20751 : larger or equal to 10 microns less than 20 microns
• CPC Class Codes: H01L 2924/20752 : larger or equal to 20 microns less than 30 microns
• CPC Class Codes: H01L 2924/20753 : larger or equal to 30 microns less than 40 microns
• CPC Class Codes: H01L 2924/20754 : larger or equal to 40 microns less than 50 microns
• CPC Class Codes: H01L 2924/3025 : Electromagnetic shielding
• CPC Class Codes: H01L 33/502 : Wavelength conversion materials
• CPC Class Codes: Y02B 20/00 : Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps

Abstract

To provide a phosphor containing a comparatively much red component and having high light emitting efficiency, high brightness and further high durability, the nitride phosphor is represented by the general formula L_XM_YN_{((2/3)X+(4/3)Y)}:R or L_XM_YO_ZN_{((2/3)X+(4/3)Y−(2/3)Z)}:R (wherein L is at least one or more selected from the Group II Elements consisting of Mg, Ca, Sr, Ba and Zn, M is at least one or more selected from the Group IV Elements in which Si is essential among C, Si and Ge, and R is at least one or more selected from the rare earth elements in which Eu is essential among Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er and Lu.); contains the another elements.

Claims

1-110. -110. (canceled)

111. A light emitting device comprising;

a light emitting element which emits light having a first luminescence spectrum and a phosphor which absorbs at least a portion of light of said first luminescence spectrum and emits light having a second luminescence spectrum which is different from said first luminescence spectrum, said phosphor being an L-M-N;

Eu, WR-base phosphor (wherein L is at least one or more elements selected from the Group II Elements consisting of Be, Mg, Ca, Sr, Ba and Zn, M is at least one or more elements selected from the Group IV Elements consisting of C, Si, Ge, Sn, Ti, Zr and Hf. N is nitrogen, Eu is europium, and WR is a rare earth element other than Eu).

112. The light emitting device according to claim 111;

wherein said phosphor comprises at least one selected from the group comprising a yttrium-aluminum oxide phosphor activated by cerium, a yttrium-gadolinium-aluminum oxide phosphor activated by cerium, and a yttrium-gallium-aluminum oxide phosphor activated by cerium.

113. A phosphor which absorbs at least a portion of light having a first luminescence spectrum and emits light having a second luminescence spectrum which is different from said first luminescence spectrum;

is characterized by being a Sr—

Ca—

Si—

N;

R-base silicon nitride having Mn wherein R is one or more rare earth elements in which Eu is essential.

114. The phosphor according to claim 113;

further comprising O.

115. The phosphor according to claim 114;

wherein a content of said O is 3% or less by weight based on the total amount of the compositions.

116. The phosphor according to claim 113;

further comprising at least one or more elements selected from the group consisting of Mg, Sr, Ca, Ba, Zn, B, Al, Cu, Mn, Cr and Ni.

117. The phosphor according to claim 113;

wherein the molar ratio of Sr to Ca is Sr Ca=1 to 9;

9 to 1.

118. The phosphor according to claim 113;

wherein the molar ratio of Sr to Ca is Sr;

Cal=1;

1.

119. The phosphor according to claim 113;

wherein a compounding amount of Eu in said phosphor is in a range of 0.003 to 0.5 mol based on Sr—

Ca, Sr and Ca.

120. The phosphor according to claim 113;

wherein the content of Eu in said phosphor is in the range of 0.005 to 0.1 mol based on Sr—

Ca, Sr and Ca.

121. The phosphor according to claim 113;

wherein the content of Mn in said phosphor is in a range of 0.001 to 0.3 mol based on Sr—

Ca, Sr and Ca.

122. The phosphor according to claim 113;

wherein the content of Mn in said phosphor is in a range of 0.0025 to 0.03 mol based on Sr—

Ca, Sr and Ca.

123. The phosphor according to claim 113;

of which a particle diameter is 3 μ

m or greater.

124. The phosphor according to claim 113;

wherein the content of Mn is 5000 ppm or less.

125. A phosphor which absorbs at least a portion of light having a first luminescence spectrum and emits light having a second luminescence spectrum which is different from said first luminescence spectrum;

is characterized by being a Sr—

Si—

N;

R-base silicon nitride having Mn wherein R is one or more rare earth elements in which Eu is essential.

126. The phosphor according to claim 125;

further comprising O.

127. The phosphor according to claim 126;

wherein a content of said O is 3% or less by weight based on the total amount of the compositions.

128. The phosphor according to claim 125;

further comprising at least one or more elements selected from the group consisting of Mg, Sr, Ca, Ba, Zn, B, Al, Cu, Mn, Cr and Ni.

129. The phosphor according to claim 125;

wherein a compounding amount of Eu in said phosphor is in a range of 0.003 to 0.5 mol based on Sr—

Ca, Sr and Ca.

130. The phosphor according to claim 125;

wherein the content of Eu in said phosphor is in the range of 0.005 to 0.1 mol based on Sr—

Ca, Sr and Ca.

131. The phosphor according to claim 125;

wherein the content of Mn in said phosphor is in a range of 0.001 to 0.3 mol based on Sr—

Ca, Sr and Ca.

132. The phosphor according to claim 125;

wherein the content of Mn in said phosphor is in a range of 0.0025 to 0.03 mol based on Sr—

Ca, Sr and Ca.

133. The phosphor according to claim 125;

of which a particle diameter is 3 μ

m or greater.

134. The phosphor according to claim 125;

wherein the content of Mn is 5000 ppm or less.

135. A light emitting device comprising a light emitting element, a first phosphor which absorbs at least the portion of light from said light emitting element and emits light having a different wave length, and a second phosphor which absorbs at least the portion of light from said light emitting element and emits light having a different wave length, wherein the peak wave length of luminescence spectrum which said light emitting element has is situated at a longer wave length side than the peak wave length of excitation spectrum which the first phosphor has and the peak wave length of excitation spectrum which the second phosphor has.

136. The light emitting device according to claim 135;

wherein the peak wave length of luminescence spectrum of the light emitting element is shifted toward shorter wavelength side in accordance with the increase of electric current density.

137. The light emitting device according to claim 135;

wherein said first phosphor and said second phosphor have a nearly equal change of luminescence intensity in accordance with the change of ambient temperatures of the first phosphor and the second phosphor.

138. The light emitting device according to claim 137;

wherein the change of ambient temperatures of the first phosphor and the second phosphor is caused by the change of the input electric current to said light emitting element.

139. The light emitting device according to claim 135;

wherein the peak wave length of luminescence spectrum of said light emitting element is in a range of 350 nm to 530 nm.

140. The light emitting device according to claim 135;

wherein said first phosphor has a higher excitation efficiency at the short wavelength side of said wave length change than the long wavelength side within a range of the wave length change of the light emitting element which is generated at changing the electric current density of the light emitting element.

141. The light emitting device according to claim 135;

wherein said first phosphor has the peak wave length of excitation spectrum which the first phosphor has at the short wavelength side of said wave length change within a range of the wave length change of the light emitting element which is generated at changing the electric current density of

the light emitting element.

142. The light emitting device according to claim 135;

wherein said first phosphor contains a yttrium-aluminum-garnet-base phosphor which contains Y and Al, and contains at least one of elements selected from the group consisting of Lu, Sc, La, Gd, Tb, Eu and Sm and at least one of elements selected from the group consisting of Ga and In and is activated by at least one of elements selected from the rare earth elements.

143. The light emitting device according to claim 135;

wherein the difference between the peak wave length of excitation spectrum which said first phosphor has and the peak wave length of excitation spectrum which said light emitting element has is 40 nm or less.

144. The light emitting device according to claim 135;

wherein said second phosphor has a higher excitation efficiency at the short wavelength side of said wave length change than the long wavelength side within a range of the wave length change of the light emitting element which is generated at changing the electric current density of the light emitting element.

145. The light emitting device according to claim 135;

wherein said light emitting device is the light source of a back light for a liquid crystal display or a light source for illumination.

146. A light emitting device comprising a light sources and a plural number of phosphors which absorb at least the portion of light from said light source and emit light having a different wave length, wherein said phosphors contain the first phosphor on at least one of the light sources and at least one of the second phosphors in which at least a portion of light emitted is absorbed in the first phosphor, said first phosphor being situated at the light source side than the second phosphors.

147. The light emitting device according to claim 146;

wherein the second phosphors are situated on at least one of the light sources, and/or at least one of light sources different from said at least one of light sources.

148. The light emitting device according to claim 146;

wherein said light emitting device has the first concave portion mounting said first phosphor and at least one of the light sources and the second concave portion mounting said second phosphor and at least one of the light sources.

149. The light emitting device according to claim 146;

wherein said second phosphor contains a yttrium-aluminum-garnet-base phosphor which contains Y and Al, and contains at least one of elements selected from the group consisting of Lu, Sc, La, Gd, Tb, Eu and Sm and at least one of elements selected from the group consisting of Ga and In and is activated by at least one of elements selected from the rare earth elements.

150. The light emitting device according to claim 146;

wherein said second phosphor has a nearly equal decreasing rate of luminescence output against the raise of temperature as said first phosphor.

151. The light emitting device according to claim 146;

wherein the light sources are semiconductor light emitting elements.

152. The light emitting device according to claim 146;

wherein said light sources are light sources which combined the semiconductor light emitting elements with the phosphors which absorb at least the portion of light from said semiconductor light emitting elements and emit light having a different wave length.

153. The light emitting device according to claim 146;

wherein the light sources have the peak wave length of luminescence spectrum of 350 nm to 530 nm.

154. The light emitting device according to claim 146;

wherein the light emitting device is the light source of a back light for a 20 liquid crystal display or a light source for illumination.

155. The light emitting device according to claim 146;

wherein light sources which emit light exciting the first phosphors and the luminescence outputs of light sources which emit light exciting the second phosphors can be respectively controlled independently.