Display unit, method of manufacturing same, organic light emitting unit, and method of manufacturing same

• US 20070102737A1
• Filed: 09/17/2004
• Published: 05/10/2007
• Est. Priority Date: 09/19/2003
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Yokoyama, Seiichi, Yamada, Jiro, Kashiwabara, Mitsuhiro, Hanawa, Kohji
• Granted Patent: US 7,973,319 B2
• Time in Patent Office: Days
• US Class Current: 257/291
• CPC Class Codes: H01L 27/153 in a repetitive configuration, e.g. LED bars
• CPC Class Codes: H10K 2102/3026 Top emission
• CPC Class Codes: H10K 2102/351 Thickness
• CPC Class Codes: H10K 50/805 Electrodes
• CPC Class Codes: H10K 50/81 Anodes
• CPC Class Codes: H10K 50/813 characterised by their shape
• CPC Class Codes: H10K 50/818 Reflective anodes, e.g. ITO combined with thick metallic layers
• CPC Class Codes: H10K 50/82 Cathodes
• CPC Class Codes: H10K 50/824 combined with auxiliary electrodes
• CPC Class Codes: H10K 50/828 Transparent cathodes, e.g. comprising thin metal layers
• CPC Class Codes: H10K 50/841 Self-supporting sealing arrangements
• CPC Class Codes: H10K 50/852 comprising a resonant cavity structure, e.g. Bragg reflector pair
• CPC Class Codes: H10K 50/856 comprising reflective means
• CPC Class Codes: H10K 59/124 Insulating layers formed between TFT elements and OLED elements
• CPC Class Codes: H10K 59/131 Interconnections, e.g. wiring lines or terminals
• CPC Class Codes: H10K 59/1315 comprising structures specially adapted for lowering the resistance
• CPC Class Codes: H10K 59/30 Devices specially adapted for multicolour light emission
• CPC Class Codes: H10K 59/35 comprising red-green-blue [RGB] subpixels
• CPC Class Codes: H10K 59/38 comprising colour filters or colour changing media [CCM]
• CPC Class Codes: H10K 59/805 Electrodes

Abstract

A display unit capable of being simply designed and manufactured by using more simplified light emitting device structure while capable of high definition display and display with superior color reproducibility and a manufacturing method thereof are provided. The display unit is a display unit (1), wherein a plurality of organic EL devices (3B), (3G), and (3R), in which a function layer (6) including a light emitting layer (11) is sandwiched between a lower electrode (4) made of a light reflective material and a semi-transmissive upper electrode (7), and which has a resonator structure in which light h emitted in the light emitting layer (11) is resonated using a space between the lower electrode (4) and the upper electrode (7) as a resonant section (15) and is extracted from the upper electrode (7) side are arranged on a substrate (2). In the respective organic EL devices (3B), (3G), and (3R), the function layer (6) is made of an identical layer, and an optical distance L of the resonant section (15) is set to a value different from each other so that blue, green, or red wavelength region is resonated.

Claims

1-68. -68. (canceled)

69. :

A display unit comprising a plurality of light emitting devices in which a function layer including at least a light emitting layer is sandwiched between a mirror made of a light reflective material and a light semi-transmissive half mirror, and which have a resonator structure for resonating light emitted in the light emitting layer by using a space between the mirror and the half mirror as a resonant section and extracting the light from the half mirror side are arranged on a substrate,

wherein in the respective light emitting devices, the light emitting layer is made of an identical layer, and the optical distance of the resonant section between the mirror and the half mirror is set to a plurality of different values.

70. :

The display unit according to claim 69, wherein in the plurality of light emitting devices, the function layer including the light emitting layer is made of an identical layer.

71. :

The display unit according to claim 69, wherein the light emitting layer emits light in blue, green, and red wavelength regions, and

in the respective light emitting devices, an optical distance is set so that extraction of light in blue, green, or red wavelength region becomes a maximum, respectively.

72. :

The display unit according to claim 69, wherein the mirror and the half mirror are used as an electrode.

73. :

The display unit according to claim 69, wherein a transparent conductive layer is provided between the mirror and the half mirror, and the optical distance is adjusted by the transparent conductive layer.

74. :

The display unit according to claim 69, wherein where a phase shift generated when light generated in the light emitting layer is reflected on the both ends of the resonant section is φ

radian, an optical distance of the resonant section is L, and a peak wavelength of the spectrum of light desired to be extracted among the light is λ

, the optical distance L is in a range that satisfies a following formula (1);

(2L)/λ

+φ

/(2π

)=m, where m is an integer 

 

(1).

75. :

The display unit according to claim 74, wherein a transparent conductive layer is provided between the mirror and the half mirror, and

where an optical distance of the transparent conductive layer is Lt, and an optical distance of the function layer including the light emitting layer is Lf, the optical distance Lt of the transparent conductive layer of the respective light emitting devices is set to satisfy a following formula (2);

Lt=L−

Lf 

 

(2).

76. :

The display unit according to claim 69, wherein a color filter for transmitting light in the wavelength regions, which is resonated in the resonant section and is extracted from the half mirror side is provided above the half mirror.

77. :

The display unit according to claim 70, wherein the light emitting layer emits light in blue, green, and red wavelength regions and,

in the respective light emitting devices, the optical distance is set so that extraction of light in blue, green, or red wavelength region becomes the maximum, respectively.

78. :

The display unit according to claim 77, wherein a color filter for transmitting light in the wavelength regions, which is resonated in the resonant section and is extracted from the half mirror side is provided above the half mirror.

79. :

The display unit according to claim 77, wherein the mirror and the half mirror are used as an electrode, and

a transparent conductive layer is provided between the mirror and the half mirror, and the optical distance is adjusted by the transparent conductive layer.

80. :

The display unit according to claim 79, wherein a color filter for transmitting light in the wavelength regions, which is resonated in the resonant section and is extracted from the half mirror side is provided above the half mirror.

81. :

The display unit according to claim 77, wherein the mirror and the half mirror are used as an electrode, and

where a phase shift generated when light generated in the light emitting layer is reflected on the both ends of the resonant section is φ

radian, an optical distance of the resonant section is L, and a peak wavelength of the spectrum of light desired to be extracted among the light is λ

, the optical distance L is in a range satisfying a following formula (1).

(2L)/λ

+φ

/(2π

)=m, where m is an integer 

 

(1).

82. :

The display unit according to claim 81, wherein a color filter for transmitting light in the wavelength regions, which is resonated in the resonant section and is extracted from the half mirror side is provided above the half mirror.

83. :

The display unit according to claim 81, wherein a transparent conductive layer is provided between the mirror and the half mirror, and

where an optical distance of the transparent conductive layer is Lt, and an optical distance of the function layer including the light emitting layer is Lf, the optical distance Lt of the transparent conductive layer of the respective light emitting devices is set to meet the following formula (2).

Lt=L−

Lf 

 

(2).

84. :

The display unit according to claim 83, wherein a color filter for transmitting light in the wavelength regions, which is resonated in the resonant section and is extracted from the half mirror side is provided above the half mirror.

85. :

The display unit according to claim 69, wherein the reflectance of the half mirror ranges from 0.1% to less than 50%.

86. :

The display unit according to claim 85, wherein a color filter for transmitting light in the wavelength regions, which is resonated in the resonant section and is extracted from the half mirror side is provided above the half mirror.

87. :

The display unit according to claim 85, wherein the mirror and the half mirror are used as an electrode, and

a transparent conductive layer is provided between the mirror and the half mirror, and the optical distance is adjusted by the transparent conductive layer.

88. :

The display unit according to claim 87, wherein a color filter for transmitting light in the wavelength regions, which is resonated in the resonant section and is extracted from the half mirror side is provided above the half mirror.

89. :

The display unit according to claim 85, wherein the mirror and the half mirror are used as an electrode, and

where a phase shift generated when light generated in the light emitting layer is reflected on the both ends of the resonant section is φ

radian, an optical distance of the resonant section is L, and a peak wavelength of the spectrum of light desired to be extracted among the light is λ

, the optical distance L is in a range satisfying a following formula (1);

(2L)/λ

+φ

/(2π

)=m, where m is an integer 

 

(1).

90. :

The display unit according to claim 89, wherein a color filter for transmitting light in the wavelength regions, which is resonated in the resonant section and is extracted from the half mirror side is provided above the half mirror.

91. :

The display unit according to claim 89, wherein a transparent conductive layer is provided between the mirror and the half mirror, and

where an optical distance of the transparent conductive layer is Lt, and an optical distance of the function layer including the light emitting layer is Lf, the optical distance Lt of the transparent conductive layer of the respective light emitting devices is set to satisfy a following formula (2);

Lt=L−

Lf 

 

(2).

92. :

The display unit according to claim 91, wherein a color filter for transmitting light in the wavelength regions, which is resonated in the resonant section and is extracted from the half mirror side is provided above the half mirror.

93. :

The display unit according to claim 85, wherein a color filter for transmitting light in the wavelength regions, which is resonated in the resonant section and is extracted from the half mirror side is provided above the half mirror,

the mirror and the half mirror are used as an electrode,

a transparent conductive layer is provided between the mirror and the half mirror,

where a phase shift generated when light generated in the light emitting layer is reflected on the both ends of the resonant section is φ

radian, an optical distance of the resonant section is L, and a peak wavelength of the spectrum of light desired to be extracted among the light is λ

, the optical distance L is in a range satisfying a following formula (1), and

where an optical distance of the transparent conductive layer is Lt, and an optical distance of the function layer including the light emitting layer is Lf, the optical distance Lt of the transparent conductive layer of the respective light emitting devices is set to satisfy a following formula (2).

(2L)/λ

+φ

/(2π

)=m, where m is an integer 

 

(1)
Lt=L−

Lf 

 

(2).

94. :

The display unit according to claim 93, wherein the optical distances Lt and Lf in the formula (2) are set so that the value of m in the formula (1) meets m=0 for the light emitting device of the light emitting devices for emitting blue light;

m=0 for the light emitting device of the light emitting devices for emitting green light; and

m=0 for the light emitting device of the light emitting devices for emitting red light.

95. :

The display unit according to claim 93, wherein the optical distances Lt and Lf in the formula (2) are set so that the value of m in the formula (1) meets m=1 for the light emitting device of the light emitting devices for emitting blue light;

m=0 for the light emitting device of the light emitting devices for emitting green light; and

m=0 for the light emitting device of the light emitting devices for emitting red light.

96. :

The display unit according to claim 93, wherein the optical distances Lt and Lf in the formula (2) are set so that the value of m in the formula (1) meets m=1 for the light emitting device of the light emitting devices for emitting blue light;

m=1 for the light emitting device of the light emitting devices for emitting green light; and

m=0 for the light emitting device of the light emitting devices for emitting red light.

97. :

The display unit according to claim 93, wherein the optical distances Lt and Lf in the formula (2) are set so that the value of m in the formula (1) meets m=1 for the light emitting device of the light emitting devices for emitting blue light;

m=1 for the light emitting device of the light emitting devices for emitting green light; and

m=1 for the light emitting device of the light emitting devices for emitting red light.

98. :

The display unit according to claim 93, wherein the optical distances Lt and Lf in the formula (2) are set so that the value of m in the formula (1) meets m=2 for the light emitting device of the light emitting devices for emitting blue light;

m=1 for the light emitting device of the light emitting devices for emitting green light; and

m=1 for the light emitting device of the light emitting devices for emitting red light.

99. :

The display unit according to claim 93, wherein the optical distances Lt and Lf in the formula (2) are set so that the value of m in the formula (1) meets m=2 for the light emitting device of the light emitting devices for emitting blue light;

m=2 for the light emitting device of the light emitting devices for emitting green light; and

m=1 for the light emitting device of the light emitting devices for emitting red light.

100. :

The display unit according to claim 93, wherein the optical distances Lt and Lf in the formula (2) are set so that the value of m in the formula (1) meets m=2 for the light emitting device of the light emitting devices for emitting blue light;

m=2 for the light emitting device of the light emitting devices for emitting green light; and

m=2 for the light emitting device of the light emitting devices for emitting red light.

101. :

A method of manufacturing a display unit, comprising forming a plurality of light emitting devices in which a function layer including at least a light emitting layer is sandwiched between a mirror made of a light reflective material and a light semi-transmissive half mirror, and which is made as a resonant section of a resonator structure for resonating light generated in the light emitting layer between the mirror and the half mirror, wherein the light emitting devices are arranged and formed on a substrate, and

wherein after the mirror or the half mirror is formed in formation regions of the respective light emitting devices on the substrate, a step of pattern-forming transparent conductive films with an optical distance different from each other and a step of forming the light emitting layer in block are performed in any order.

102. :

The method of manufacturing a display unit according to claim 101, wherein a step of forming the function layer including the light emitting layer in block in the formation regions of the respective light emitting devices on the substrate is performed.

103. :

The method of manufacturing a display unit according to claim 101, wherein a step of forming the half mirror so that the reflectance is in the range from 0.1% to less than 50% is performed.

104. :

The method of manufacturing a display unit according to claim 103, wherein a step of forming the function layer including the light emitting layer in block in the formation regions of the respective light emitting devices on the substrate is performed.

105. :

An organic light emitting unit comprising three organic light emitting devices provided on a substrate, wherein the three organic light emitting devices have a structure in which a first electrode layer, a layer including a light emitting layer, and a second electrode layer are layered from the substrate side, and convert light generated in the light emitting layer to light of three colors different from each other and emit the converted light,

wherein the first electrode layer has a structure in which a contact layer for improving contact characteristics with the substrate, a resonant layer for resonating light generated in the light emitting layer between the resonant layer and the second electrode layer, and a barrier layer for protecting the resonant layer are layered from the substrate side, and

the thickness of the barrier layer is different from each other among the three organic light emitting devices.

106. :

The organic light emitting unit according to claim 105, wherein the thickness of the layer including the light emitting layer is equal to each other among the three organic light emitting devices.

107. :

The organic light emitting unit according to claim 105, wherein the layer including the light emitting layer is an organic layer.

108. :

The organic light emitting unit according to claim 105, wherein the light emitting layer generates light of color equal to each other among the three organic light emitting devices.

109. :

The organic light emitting unit according to claim 105, wherein the light emitting layer has a structure in which a red light emitting layer for generating red light, a green light emitting layer for emitting green light, and a blue light emitting layer for generating blue light are layered from the first electrode layer side.

110. :

The organic light emitting unit according to claim 105, wherein the thickness of the barrier layer is different from each other correspondingly to the light of three colors emitted from the three organic light emitting devices.

111. :

The organic light emitting unit according to claim 110, wherein the thickness of the barrier layer is set so that the three organic light emitting devices can convert light generated in the light emitting layer to red light, green light, and blue light, respectively and emit the converted light.

112. :

The organic light emitting unit according to claim 111, wherein the thickness of the barrier layer is ranked in descending order corresponding to the red light, the green light, and the blue light emitted from the three organic light emitting devices.

113. :

The organic light emitting unit according to claim 105, wherein the thickness of the barrier layer ranges from 1 nm to 100 nm.

114. :

The organic light emitting unit according to claim 105, wherein the barrier layer is made of a light transmissible material containing at least one metal from the group consisting of indium, tin, zinc, cadmium, titanium, chromium, gallium, and aluminum;

an alloy of the metal;

a metal oxide thereof; and

a metal nitride thereof.

115. :

The organic light emitting unit according to claim 105, wherein the barrier layer is made of a light transmissible material containing at least one metal oxide from the group consisting of indium tin oxide, indium zinc oxide, indium oxide, tin oxide, zinc oxide, cadmium oxide, titanium oxide, and chromium oxide.

116. :

The organic light emitting unit according to claim 105, wherein the barrier layer is made of a material with work function larger than of the resonant layer.

117. :

The organic light emitting unit according to claim 105, wherein the contact layer is made of at least one metal from the group consisting of chromium, indium, tin, zinc, cadmium, titanium, aluminum, magnesium, and molybdenum;

an alloy of the metal;

a metal oxide thereof;

or a metal nitride thereof.

118. :

The organic light emitting unit according to claim 105, wherein the resonant layer is made of silver or an alloy containing silver.

119. :

The organic light emitting unit according to claim 105, wherein the resonant layer is made of an alloy containing silver and at least one from the group consisting of palladium, neodymium, samarium, yttrium, cerium, europium, gadolinium, terbium, dysprosium, erbium, ytterbium, scandium, ruthenium, copper, and gold.

120. :

The organic light emitting unit according to claim 105, wherein a planarizing layer for flattening the base region on which the three organic light emitting devices are arranged is provided for the substrate, and

the contact layer is intended to improve contact characteristics with the planarizing layer.

121. :

The organic light emitting unit according to claim 105, wherein the optical distance L between the resonant layer and the second electrode layer satisfies a following formula (3);

(2L)/λ

+φ

/(2π

)=m 

 

(3)

wherein regarding L, λ

, φ

, and m, L represent an optical distance between the resonant layer including a first end face adjacent to the barrier layer in the resonant layer and the second electrode layer including a second end face adjacent to the layer including the light emitting layer in the second electrode layer;

λ

represents peak wavelength of the spectrum of light desired to be emitted;

φ

represents a phase shift of reflected light generated on the resonant layer including the first end face and the second electrode layer including the second end face; and

m represents 0 or an integer, respectively.

122. :

The organic light emitting unit according to claim 105, wherein the three organic light emitting devices resonate light generated in the light emitting layer between the resonant layer and the second electrode layer, and then emit the light of three colors through one of the first electrode layer and the second electrode layer.

123. :

The organic light emitting unit according to claim 122, wherein the three organic light emitting devices emit the light of three colors through the first electrode layer, and

the thickness of the resonant layer is ranges from 1 nm to 50 nm, and the thickness of the second electrode layer is ranges from 100 nm to 300 nm.

124. :

The organic light emitting unit according to claim 122, wherein the three organic light emitting devices emit the light of three colors through the second electrode layer, and

the thickness of the resonant layer is ranges from 100 nm to 300 nm, and the thickness of the second electrode layer ranges from 1 nm to 10 nm.

125. :

A method of manufacturing an organic light emitting unit comprising forming three organic light emitting devices provided on a substrate, wherein the three organic light emitting devices have a structure in which a first electrode layer, a layer including a light emitting layer, and a second electrode layer are layered from the substrate side, and convert light generated in the light emitting layer to light of three colors different from each other and emit the converted light,

wherein a step of forming the first electrode layer so that the first electrode layer has a structure in which a contact layer for improving contact characteristics with the substrate, a resonant layer for resonating light generated in the light emitting layer between the resonant layer and the second electrode layer, and a barrier layer for protecting the resonant layer are layered from the substrate side is included, and

the thickness of the barrier layer is different from each other among the three organic light emitting devices.

126. :

The method of manufacturing an organic light emitting unit according to claim 125, wherein the step of forming the first electrode layer includes the steps of;

layering the contact layer, the resonant layer, and a first barrier layer portion composing part of the barrier layer in this order over the substrate;

pattern-forming a first mask on a first region of the first barrier layer portion where a first organic light emitting device of the three organic light emitting devices is to be formed;

forming a second barrier layer portion composing another part of the barrier layer over the first mask and the peripheral first barrier layer portion;

pattern-forming a second mask on a second region of the second barrier layer portion where a second organic light emitting device of the three organic light emitting devices is to be formed;

forming a third barrier layer portion composing still another part of the barrier layer over the second mask and the peripheral second barrier layer portion;

pattern-forming a third mask on a third region of the third barrier layer portion where a third organic light emitting device of the three organic light emitting devices is to be formed; and

continuously etching and patterning the contact layer, the resonant layer, and the first, the second, and the third barrier layer portions by using the first, the second, and the third masks, and

the barrier layer of the first electrode layer is formed from the first barrier layer portion in the first region, is formed from the first and the second barrier layer portions in the second region, and is formed from the first, the second, and the third barrier layer portions in the third region.

127. :

The method of manufacturing an organic light emitting unit according to claim 126, wherein the first, the second, and the third organic light emitting devices are made to emit blue light, green light, and red light, respectively.

128. :

The method of manufacturing an organic light emitting unit according to claim 125, wherein the step of forming the first electrode layer includes the steps of;

layering the contact layer, the resonant layer, and a first, a second, and a third barrier layer portions composing the barrier layer in this order over the substrate;

pattern-forming a first mask on a first region of the third barrier layer portion where a first organic light emitting device of the three organic light emitting devices is to be formed;

leaving the third barrier layer portion in the first region and exposing the second barrier layer portion in the peripheral region of the first region by etching and patterning the third barrier layer portion by using the first mask;

pattern-forming a second mask on a second region of the exposed face of the second barrier layer portion where a second organic light emitting device of the three organic light emitting devices is to be formed;

leaving the second barrier layer portion in the first and the second regions and exposing the first barrier layer portion in the peripheral region of the first and the second regions by etching and patterning the second barrier layer portion by using the first mask together with the second mask;

pattern-forming a third mask on a third region of the exposed face of the first barrier layer portion where a third organic light emitting device of the three organic light emitting devices is to be formed; and

leaving the first barrier layer portion in the first, the second, and the third regions by continuously etching and patterning the contact layer, the resonant layer, and the first barrier layer portion by using the first and the second masks together with the third mask, and

the barrier layer of the first electrode layer is formed from the first, the second, and the third barrier layer portions in the first region, is formed from the first and the second barrier layer portions in the second region, and is formed from the first barrier layer portion in the third region.

129. :

The method of manufacturing an organic light emitting unit according to claim 128, wherein the first, the second, and the third organic light emitting devices are made to emit red light, green light, and blue light, respectively.

130. :

The method of manufacturing an organic light emitting unit according to claim 125, wherein the barrier layer is formed by using a light transmissible material containing at least one metal from the group consisting of indium, tin, zinc, cadmium, titanium, chromium, gallium, and aluminum;

an alloy of the metal;

a metal oxide thereof; and

a metal nitride thereof.

131. :

The method of manufacturing an organic light emitting unit according to claim 125, wherein the barrier layer is formed by using a light transmissible material containing at least one metal oxide from the group consisting of indium tin oxide, indium zinc oxide, indium oxide, tin oxide, zinc oxide, cadmium oxide, titanium oxide, and chromium oxide.

132. :

The method of manufacturing an organic light emitting unit according to claim 125, wherein the contact layer is formed by using at least one metal from the group consisting of chromium, indium, tin, zinc, cadmium, titanium, aluminum, magnesium, and molybdenum;

an alloy of the metal;

a metal oxide thereof;

or a metal nitride thereof.

133. :

The method of manufacturing an organic light emitting unit according to claim 125, wherein the resonant layer is formed by using silver or an alloy containing silver.

134. :

The method of manufacturing an organic light emitting unit according to claim 125, wherein the resonant layer is formed by using an alloy containing silver and at least one from the group consisting of palladium, neodymium, samarium, yttrium, cerium, europium, gadolinium, terbium, dysprosium, erbium, ytterbium, scandium, ruthenium, copper, and gold.

135. :

The method of manufacturing an organic light emitting unit according to claim 125, wherein a step of forming a planarizing layer for flattening the base region on which the three organic light emitting devices are to be formed is provided for the substrate is included, and

the contact layer is formed on the planarizing layer.

136. :

A display unit comprising an organic light emitting unit having a structure in which three organic light emitting devices are provided on a substrate, wherein the three organic light emitting devices of the organic light emitting unit have a structure in which a first electrode layer, a layer including a light emitting layer, and a second electrode layer are layered from the substrate side, and images are displayed by converting light generated in the light emitting layer to light of three colors different from each other and emitting the converted light,

wherein the first electrode layer has a structure in which a contact layer for improving contact characteristics with the substrate, a resonant layer for resonating light generated in the light emitting layer between the resonant layer and the second electrode layer, and a barrier layer for protecting the resonant layer are layered, and

the thickness of the barrier layer is different from each other among the three organic light emitting devices.