Light emitting element and method for controlling light emitting element

Abstract

A light-emitting element and a control method of the light-emitting element, the light-emitting element comprising: a first electrode; a second electrode, which is opposite to the first electrode; a light-emitting layer, which is arranged between the first electrode and the second electrode and contains a phosphor; a laminate, which has a thickness capable of injecting charges from the second electrode into the light-emitting layer and comprises a metal layer, a first insulating layer and a second insulating layer, the first insulating layer being arranged on the second electrode side of the metal layer, and the second insulating layer being arranged on the light-emitting layer side of the metal layer; a first power source, which applies a voltage between the first electrode and the second electrode; and a second power source, which applies a voltage between the metal layer and the second electrode, the voltage having a polarity opposite to the polarity of the second electrode when the voltage is applied between the first electrode and the second electrode by the first power source.

Description

Technical Field

[0001] The present invention relates to a light emitting element and a method for controlling the light emitting element. Background Art

[0002] For example, Patent Document 1 discloses an organic electroluminescent element in which a cathode, an organic light-emitting layer, an inorganic thin film layer, and an anode are stacked.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2000-235893 Summary of the invention

[0006] Technical Problems to be Solved by the Invention

[0007] In order to drive the organic electroluminescent element (light-emitting portion) described in Patent Document 1, a switching element such as a thin film transistor (TFT) can be used. That is, the light-emitting portion and the TFT can be combined to function as a light-emitting element. In addition, as a method of connecting the TFT and the light-emitting portion, for example, stacking and connecting the two is considered. However, depending on the combination of the type of TFT, the composition of the light-emitting portion, the stacking order of the TFT and the light-emitting portion, etc., the luminous efficiency of the light-emitting element is sometimes not obtained. Therefore, one aspect of the present invention is to provide a light-emitting element that can obtain good luminous efficiency.

[0008] Solutions to the problem

[0009] A light-emitting element according to one aspect of the present invention includes: a first electrode; a second electrode, which is opposite to the first electrode; a light-emitting layer, which is arranged between the first electrode and the second electrode and contains a phosphor; a laminate, which has a thickness capable of injecting charges from the second electrode into the light-emitting layer and includes a metal layer, a first insulating layer and a second insulating layer, the first insulating layer being arranged on the second electrode side of the metal layer, and the second insulating layer being arranged on the light-emitting layer side of the metal layer; a first power source, which applies a voltage between the first electrode and the second electrode; and a second power source, which applies a voltage between the metal layer and the second electrode so that the second electrode becomes a voltage of a polarity opposite to the polarity of the voltage applied between the first electrode and the second electrode by the first power source.

[0010] Effects of the Invention

[0011] One aspect of the present invention can provide a light-emitting element capable of obtaining good light-emitting efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1It is a cross-sectional view schematically showing an example of a stacked structure of the light emitting element according to the first embodiment.

[0013] Figure 2 This is a timing chart showing an example of a method for controlling the first power supply and the second power supply of the light emitting element according to the first embodiment.

[0014] Figure 3 This is a timing chart showing an example of a method for controlling the first power supply and the second power supply of the light emitting element according to the first embodiment.

[0015] Figure 4 This is a timing chart showing an example of a method for controlling the first power supply and the second power supply of the light emitting element according to the first embodiment.

[0016] Figure 5 This is a flowchart showing an example of a process for manufacturing the light emitting element according to the first embodiment.

[0017] Figure 6 It is shown Figure 1 A flowchart of an example of a manufacturing process of a functional laminate in FIG.

[0018] Figure 7 1 is a timing chart showing an example of a method for controlling the first power supply and the second power supply of the light emitting element according to the second embodiment.

[0019] Figure 8 1 is a timing chart showing an example of a method for controlling the first power supply and the second power supply of the light emitting element according to the second embodiment. DETAILED DESCRIPTION

[0020] [First embodiment]

[0021] Hereinafter, one embodiment of the present disclosure will be described. Figure 1 It is a cross-sectional view schematically showing an example of a stacked structure of the light emitting element 1 according to the present embodiment.

[0022] like Figure 1 As shown in FIG. 1 , the light emitting element 1 includes, for example, a thin film transistor (TFT) 10 and a light emitting portion 20 provided on a substrate 2. The light emitting portion 20 is controlled by the TFT 10 as a switching element to emit light. Figure 1 In the description, one pixel is described, and for example, a display device can be formed by arranging a plurality of such pixels.

[0023] The TFT 10 includes, for example, a gate electrode 11 , a gate insulating layer 12 , a channel layer 13 , a source electrode 14 , and a drain electrode 15 .

[0024] The gate electrode 11 is formed on the substrate 2. An insulating layer may be provided between the substrate 2 and the gate electrode 11. The gate electrode 11 is formed of a metal material such as copper or titanium.

[0025] The gate insulating layer 12 is formed on the gate electrode 11. The gate insulating layer 12 insulates the gate electrode 11. The gate insulating layer 12 is formed of a transparent insulating material such as silicon nitride or silicon oxide.

[0026] The channel layer 13 is formed on the gate electrode 11 and the gate insulating layer 12. The TFT 10 in this embodiment is, for example, an n-channel TFT. The channel layer 13 is composed of an n-type semiconductor (hereinafter, the n-type semiconductor in the channel layer 13 is sometimes referred to as a second n-type semiconductor). Examples of materials that can be used as the n-type semiconductor include IGZO (indium gallium zinc oxide), IZO (indium zinc oxide), GZO (gallium-doped zinc oxide), AZO (aluminum-doped zinc oxide), ZnO, In 2 O 3 , Ga 2 O 3 , etc. In addition, the portion of the channel layer 13 connected to the source electrode 14 and the portion connected to the drain electrode 15 are doped with impurities to become a p-type semiconductor. In the above, the case where the TFT 10 is an n-channel TFT has been described, but it is not limited to this. The TFT 10 may also be, for example, a p-channel TFT.

[0027] The source electrode 14 and the drain electrode 15 are formed on the channel layer 13 and are respectively connected to the channel layer 13. The source electrode 14 and the drain electrode 15 are formed of a metal material such as copper or titanium.

[0028] For example, a planarization layer 16 is stacked on the TFT 10. The planarization layer 16 insulates, for example, the channel layer 13, the source electrode 14, and the drain electrode 15. The planarization layer 16 is made of an insulating material such as acrylic resin or polyimide resin.

[0029] The light emitting portion 20 is formed on the planarizing layer 16 . The light emitting portion 20 is electrically connected to the TFT 10 .

[0030] like Figure 1 As shown, the light-emitting portion 20 in this embodiment has, for example, a light-emitting layer 22, which is sandwiched between a cathode 21 as a second electrode and an anode 24 as a first electrode. In addition, a hole transport layer 23 is provided between the anode 24 and the light-emitting layer 22. Moreover, a functional laminate 30 is provided between the cathode 21 and the light-emitting layer 22.

[0031] The anode 24 supplies holes to the light emitting layer 22. The anode 24 is disposed opposite to the cathode 21. The anode 24 is, for example, made of a conductive material having conductivity. It is also preferred that the anode 24 is transparent. Specific examples of the transparent conductive material include ITO (indium tin oxide), IZO (indium zinc oxide), SnO 2 (tin oxide), FTO (fluorine-doped tin oxide), etc.

[0032] The anode 24 is electrically connected to the source electrode 14, for example. Thus, the anode 24 is electrically connected to the cathode 21 via the TFT 10 as a switching element. Furthermore, for example, a first power source 40 is provided between the anode 24 and the source electrode 14. The first power source 40 applies a voltage between the anode 24 and the cathode 21 such that the cathode 21 becomes negative.

[0033] The cathode 21 supplies electrons to the light emitting layer 22. In addition, the cathode 21 in the present embodiment is composed of, for example, an n-type semiconductor. Examples of materials that can be used as the n-type semiconductor include IGZO (indium gallium zinc oxide), IZO (indium zinc oxide), GZO (gallium-doped zinc oxide), AZO (aluminum-doped zinc oxide), ZnO, In 2 O 3 , Ga 2 O 3 Oxide semiconductors.

[0034] Moreover, the cathode 21 is electrically connected to the drain electrode 15. Preferably, the cathode 21 is directly connected to the drain electrode 15. In addition, since the cathode 21 in the present embodiment is formed of an n-type semiconductor, it also has the functions of a so-called electron injection layer that promotes the injection of electrons into the light-emitting layer 22 and an electron transport layer that transports electrons to the light-emitting layer 22. Therefore, there is no need to set an electron injection layer and an electron transport layer on the basis of the cathode 21, and the bonding interface between the cathode 21 and the electron injection layer that can serve as a barrier to electron injection is reduced, which can reduce the driving voltage of the light-emitting element 1 and obtain good luminous efficiency. Moreover, it can be formed using the same equipment as the channel layer 13 of the above-mentioned TFT10, which can simplify the manufacturing process and reduce the manufacturing cost.

[0035] In addition, although the cathode 21 is described above as being composed of an n-type semiconductor, it may also be composed of a conductive material having conductivity. Examples of such conductive materials include ITO (indium tin oxide), IZO (indium zinc oxide), SnO 2 (tin oxide), FTO (fluorine-doped tin oxide), etc. When the cathode 21 is formed of a conductive material, for example, an electron injection layer, an electron transport layer, etc. may be provided on the light emitting layer 22 side of the cathode 21 .

[0036] The light-emitting layer 22 emits light by holes supplied from the anode 24 and electrons supplied from the cathode 21. That is, the light-emitting layer 22 is provided between the cathode 21 and the anode 24. The light-emitting layer 22 contains, for example, a phosphor. Examples of the phosphor include quantum dots, which are organic light-emitting materials and semiconductor nanoparticles.

[0037] The hole transport layer 23 transports holes from the anode 24 to the light emitting layer 22. It is preferable that the hole transport layer 23 is transparent. Specific examples of materials for the hole transport layer 23 include NiO, Cr 2 O 3 、MgO、LaNiO 3 、MoO 3 , WO 3 Etc. In addition, the hole transport layer 23 may also function as a hole injection layer that promotes the injection of holes from the anode 24 into the light-emitting layer 22 .

[0038] In this embodiment, the light emitting layer 22 and the hole transport layer 23 are formed into a predetermined pattern separated into islands in the bank 25. The bank 25 is made of insulating materials such as acrylic resin and polyimide resin. On the other hand, the anode 24 is a common electrode formed on the entire surface.

[0039] The functional laminate 30 is a laminate in which a first insulating layer 31, a metal layer 32, and a second insulating layer 33 are laminated from the cathode 21 side. The functional laminate 30 is, for example, a laminate having a thickness capable of injecting electrons (charges) from the cathode 21 to the light-emitting layer 22, thereby promoting the supply of electrons from the cathode 21 to the light-emitting layer 22. The thickness of the functional laminate layer 30 is preferably 3 nm or more and 20 nm or less. In addition, the thickness of the first insulating layer 31, the metal layer 32, and the second insulating layer 33 can be measured, for example, by SEM (scanning electron microscope) and / or optical microscope.

[0040] The first insulating layer 31 insulates the metal layer 32 from the cathode 21. The first insulating layer 31 is made of, for example, an organic material such as polyimide resin or acrylic resin, SiN, SiO 2 ,SiON,SiC,AlN,AlON,Al 2 O 3 In addition, the thickness of the first insulating layer 31 is more preferably not less than 1 nm and not more than 5 nm, and more preferably not less than 3 nm and not more than 5 nm.

[0041] The second insulating layer 33 insulates the metal layer 32 from the light emitting layer 22. The second insulating layer 33 is in direct contact with the light emitting layer 22. The thickness of the second insulating layer 33 is preferably 5 nm or less. The second insulating layer 33 is made of an organic material such as polyimide resin or acrylic resin, SiN, SiO 2,SiON,SiC,AlN,AlON,Al 2 O 3 In addition, the thickness of the second insulating layer 33 is preferably greater than or equal to 1 nm and less than or equal to 5 nm, and more preferably greater than or equal to 3 nm and less than or equal to 5 nm.

[0042] In addition, the functional laminate 30 in this embodiment is formed in a predetermined pattern separated, for example, in an island shape, in the insulating layer 34. The first insulating layer 31, the second insulating layer 33, and the insulating layer 34 are made of insulating materials such as acrylic resin and polyimide resin.

[0043] The metal layer 32 is formed of metal materials such as Al (aluminum), Mg (magnesium), Ag (silver), Cu (copper), Au (gold), Pt (platinum), Ni (nickel), Mo (molybdenum), Cr (chromium), etc. In addition, the metal layer 32 is electrically connected to the drain electrode 15, for example. Thus, the metal layer 32 is electrically connected to the cathode 21 via the drain electrode 15. Moreover, a second power supply 41 is provided between the metal layer 32 and the cathode 21. The second power supply 41 applies a voltage between the metal layer 32 and the cathode 21 so that the cathode 21 becomes positive. That is, the polarity of the cathode 21 when the voltage is applied between the metal layer 32 and the cathode 21 by the second power supply 41 is the opposite polarity to the polarity of the cathode 21 when the voltage is applied between the anode 24 and the cathode 21 by the first power supply 40. By using the electric field generated by the voltage applied by the second power supply 41, the CBM in the cathode 21 and the first insulating layer 31 can be tilted, and electrons can be accelerated from the cathode 21 and pass through the first insulating layer 31. Furthermore, the thickness of the metal layer 32 is preferably not less than 1 nm and not more than 10 nm. This allows, for example, electrons to be more efficiently supplied from the cathode 21 to the light-emitting layer 22 via the functional laminate 30 .

[0044] Figure 2 as well as Figure 3 , Figure 4 An example of a control method of the first power source 40 and the second power source 41 is shown respectively. Figure 2 as well as Figure 3 , Figure 4 The positive and negative of the first power supply applied voltage and the second power supply applied voltage respectively indicate the polarity of the cathode 21 .

[0045] As a control method of the light emitting element 1, for example, Figure 2 As shown, it is preferable to control so that the period when the first power supply 40 applies a voltage between the anode 24 and the cathode 21 that makes the cathode 21 negative is synchronized with the period when the second power supply 41 applies a voltage between the metal layer 32 and the cathode 21 that makes the cathode 21 positive. In this way, electrons can be more reliably injected from the cathode 21 to the light-emitting layer 22. In addition, when using Figure 2In the case of the control method of the light emitting element 1 shown in the figure, it is preferable that the metal layer 32 is connected to the drain electrode 15 of the TFT 10. In the case where the metal layer 32 is connected to the drain electrode 15, the first power source 40 and the second power source 41 can be turned on and off synchronously by switching based on the TFT 10, and power consumption can be reduced. In addition, as long as the period during which the first power source 40 applies a voltage between the anode 24 and the cathode 21 that makes the cathode 21 negative and the period during which the second power source 41 applies a voltage between the metal layer 32 and the cathode 21 that makes the cathode 21 negative are at least partially synchronized.

[0046] Furthermore, as a control method of the light emitting element 1, Figure 3 As shown, the second power supply 41 may be controlled so as to always apply a voltage between the metal layer 32 and the cathode 21 to make the cathode 21 positive. Thus, the electrostatic capacitance between the metal layer 32 and the cathode 21 can be ignored, and a high-speed response with less delay can be achieved.

[0047] Furthermore, as a control method of the light emitting element 1, Figure 4 As shown, the first power supply 40 can also be controlled so that the voltage between the anode 24 and the cathode 21 is always applied to the cathode 21 to make the cathode 21 negative, and the timing of the second power supply 41 applying the voltage between the metal layer 32 and the cathode 21 to make the cathode 21 positive can be controlled.

[0048] The ratio of the voltage applied by the second power source 41 to the voltage applied by the first power source 40 is preferably 80 to 120, more preferably 90 to 110. Thus, electrons can be more efficiently supplied from the cathode 21 to the light-emitting layer 22 via the functional laminate 30 .

[0049] In addition, the metal layer 32 may also function as a reflective layer that reflects light irradiated from the light emitting layer 22. Thus, the light emitting element 1 functions as a so-called top emission type light emitting element that reflects light from the light emitting layer 22 at the metal layer 32 and displays toward the anode 24 side. In the case where the metal layer 32 functions as a reflective layer, the thickness of the metal layer 32 is preferably, for example, 1 nm or more and 10 nm or less, and more preferably 3 nm or more and 10 nm or less. In addition, from the viewpoint of reflectivity, etc., the metal layer 32 as a reflective layer is preferably Al.

[0050] The light emitting element 1 according to this embodiment includes: a functional laminate 30, which is a laminate in which a first insulating layer 31, a metal layer 32, and a second insulating layer 33 are laminated from the cathode 21 side; a first power source 40, which applies a voltage between the anode 24 and the cathode 21 so that the cathode 21 becomes negative; and a second power source 41, which applies a voltage between the metal layer 32 and the cathode 21 so that the cathode 21 becomes positive. The voltage of the first power source 40 and the voltage of the second power source 41 enable electrons to be efficiently supplied from the cathode 21 to the light emitting layer 22 via the functional laminate 30.

[0051] Next, refer to Figure 1 and Figure 5 An example of a method for manufacturing the light emitting element 1 according to this embodiment will be described.

[0052] First, the TFT 10 is formed on the substrate 2 ( S1 ). The method for forming the TFT 10 is not particularly limited, and for example, the TFT 10 can be manufactured by a conventional method.

[0053] A planarization layer 16 is formed on the TFT 10 to make the surface planar ( S2 ). The planarization layer 16 can be formed by, for example, applying a solution in which an insulating material such as polyimide is dissolved on the TFT 10 and then baking the solution.

[0054] The cathode 21 is formed on the planarization layer 16 (S3). The cathode 21 is formed by, for example, sputtering. The cathode 21 is patterned into, for example, a predetermined shape.

[0055] More specifically, first, for example, a first mask is formed to open a portion corresponding to the drain electrode 15 on the planarization layer 16. Then, by ashing through the first mask, the planarization layer 16 at the opening of the first mask is removed to form a contact hole portion that exposes the drain electrode 15. Then, the first mask is removed.

[0056] Furthermore, a second mask is formed to cover the portion of the planarization layer 16 where the cathode is not formed, and a layer of a material for forming the cathode 21 is formed. Then, while removing the second mask, the portion corresponding to the second mask is removed, thereby forming the cathode 21 having a predetermined shape. Thus, the cathode 21 and the drain electrode 15 are electrically connected via the contact hole portion. Furthermore, the cathode 21 and the channel layer 13 are also electrically connected via the drain electrode 15.

[0057] The functional laminate 30 is formed on the cathode 21 (S4). For more details on the formation of the functional laminate 30, refer to Figure 6 Provide explanation.

[0058] For example, Figure 6As shown, the insulating layer 34 is formed on the cathode 21 (S41). The insulating layer 34 can be formed by, for example, applying a solution in which an insulating material such as polyimide is dissolved on the TFT 10 and then baking the solution.

[0059] A third mask is formed to open portions corresponding to the cathode 21 on the insulating layer 34. Then, by ashing through the third mask, the insulating layer 34 in the openings of the third mask is removed, and openings for exposing the cathode 21 are formed.

[0060] The first insulating layer 31 is formed on the cathode 21 in the opening (S41). The first insulating layer 31 can be formed by coating a layer containing Al dissolved therein. 2 O 3 A solution of insulating material such as a silicon wafer is formed by baking.

[0061] The metal layer 32 is formed on the first insulating layer 31 in the opening (S42). The metal layer 32 can be formed by sputtering, for example.

[0062] The second insulating layer 33 is formed on the metal layer 32 in the opening (S43). The second insulating layer 33 can be formed by coating a metal layer containing Al 2 O 3 A solution of insulating material such as a silicon wafer is formed by baking.

[0063] Furthermore, the third mask is removed, thereby forming the functional stacked body 30 embedded in the insulating layer 34 .

[0064] The bank 25 is formed on the functional laminate 30 (S5). The bank 25 can be formed, for example, by the same method as the planarization layer 16. More specifically, for example, an insulating material is applied to the cathode 21 and baked to form a layer made of an insulating material. Then, a fourth mask is formed on the layer made of the insulating material to open a portion corresponding to the cathode 21. Then, ashing is performed through the fourth mask to form the bank 25 having an opening portion exposing the cathode 21. Then, the fourth mask is removed.

[0065] The light-emitting layer 22 is formed on the cathode 21 exposed in the opening of the bank 25 (S6). That is, the light-emitting layer 22 patterned into a predetermined shape corresponding to the opening of the bank 25 is formed. The light-emitting layer 22 can be formed by various methods such as evaporation of a light-emitting material such as a phosphor through a mask or inkjet coating to the opening of the bank 25.

[0066] The hole transport layer 23 is formed on the light emitting layer 22 formed in the opening of the bank 25 (S7). That is, the hole transport layer 23 patterned into a predetermined shape corresponding to the opening of the bank 25 is formed. The hole transport layer 23 can be formed by various methods such as evaporation of a light emitting material such as a phosphor through a mask, inkjet coating to the opening of the bank 25, etc.

[0067] The anode 24 is formed on the bank 25 and the hole transport layer 23 ( S8 ). The anode 24 can be formed by, for example, sputtering. Alternatively, the anode 24 can be formed on the entire surface of the substrate 2 on the hole transport layer 23 .

[0068] Furthermore, after forming the anode 24 , a sealing layer may be formed to seal the light emitting element 1 .

[0069] Thus, the light emitting element 1 involved in this embodiment can be manufactured. According to the above method, after the cathode 21 is formed, the bank 25, the light emitting layer 22, etc. are formed. In this embodiment, since the cathode 21 is formed of, for example, an oxide semiconductor material, it is resistant to the environment when the bank 25, the light emitting layer 22, etc. are formed. Therefore, it is possible to suppress the degradation of the luminous efficiency when the light emitting element 1 is manufactured. On the other hand, when a metal material such as Mg or Al is used for the cathode, it is possible that the bank 25, the light emitting layer 22, etc. are degraded due to oxidation in the environment when the bank 25, the light emitting layer 22, etc. are formed, and the luminous efficiency may be degraded when the light emitting element 1 is manufactured.

[0070] In the above embodiment, the embodiment in which the first electrode is an anode and the second electrode is a cathode is described, but in other embodiments, the first electrode may be a cathode and the second electrode may be an anode. In other embodiments, the first power supply applies a voltage between the first electrode and the second electrode so that the polarity of the second electrode becomes positive, and the second power supply applies a voltage between the metal layer and the second electrode so that the polarity of the second electrode becomes negative. Thus, the functional laminate can efficiently perform hole (charge) injection from the anode as the second electrode to the light-emitting layer.

[0071] [Second embodiment]

[0072] Hereinafter, one embodiment of the present disclosure will be described. In the first embodiment, the second power supply 41 is a DC power supply, and in the second embodiment, the second power supply 41 is an AC power supply. The other configurations are the same as those of the first embodiment, and thus the description thereof is omitted. Figure 7 and Figure 8 An example of a control method of the first power supply 40 and the second power supply in the second embodiment is described. Figure 7 and Figure 8 The positive and negative numbers of the first power supply applied voltage and the second power supply applied voltage respectively indicate the polarities of the second electrode.

[0073] like Figure 7 As shown, in the light emitting element 1 of the second embodiment, the second power supply may be an AC power supply, so that during the period when the first power supply does not apply a voltage between the first electrode and the second electrode, the second power supply applies a voltage between the metal layer and the second electrode so that the polarity of the second electrode becomes the same as the polarity of the second electrode when the voltage is applied between the first electrode and the second electrode by the first power supply. When the light emitting element 1 is turned off, the polarity of the voltage applied by the second power supply 41 is reversed, and a voltage is applied to make the cathode 23 positive, so that the residual charge accumulated in the cathode 21 or the light emitting layer 22 can be released. The electrostatic capacitance between the metal layer 32 and the cathode 21 can be ignored, and a high-speed response with less delay can be performed.

[0074] Moreover, if Figure 8 As shown, in the light-emitting element 1 of the second embodiment, the brightness of the light-emitting element 1 can also be controlled by the second power supply being an AC power supply, the first power supply always applying a voltage between the first electrode and the second electrode, and the second power supply applying a voltage between the metal layer and the second electrode so that the polarity of the second electrode becomes the same as the polarity of the second electrode when the voltage is applied between the first electrode and the second electrode by the first power supply.

[0075] The second power supply 41 reverses the polarity of the voltage applied and drives. When the light emitting element 1 is turned off, the polarity of the voltage applied by the second power supply 41 is reversed and a positive voltage is applied to the cathode 23, thereby releasing the excess charge accumulated in the cathode 21 or the light emitting layer 22.

[0076] The present invention is not limited to the above-described embodiments, and may be replaced with a configuration that is substantially the same as the configuration shown in the above-described embodiments, a configuration that achieves the same function and effect, or a configuration that can achieve the same purpose.

Claims

1. A light emitting element, It is characterized in that include: a first electrode; a second electrode, which is opposite to the first electrode; a light-emitting layer disposed between the first electrode and the second electrode and comprising a phosphor; a laminate having a thickness capable of injecting charges from the second electrode into the light-emitting layer, and comprising a metal layer, a first insulating layer, and a second insulating layer, wherein the first insulating layer is disposed on the second electrode side of the metal layer, and the second insulating layer is disposed on the light-emitting layer side of the metal layer; a first power source having a voltage between the first electrode and the second electrode; as well as a second power source for applying a voltage between the metal layer and the second electrode, the polarity of which is opposite to the polarity of the second electrode when a voltage is applied between the first electrode and the second electrode by the first power source; The second insulating layer is directly connected to the light emitting layer.

2. A light emitting element, It is characterized in that include: a first electrode; a second electrode, which is opposite to the first electrode; a light-emitting layer disposed between the first electrode and the second electrode and comprising a phosphor; a laminate having a thickness capable of injecting charges from the second electrode into the light-emitting layer, and comprising a metal layer, a first insulating layer, and a second insulating layer, wherein the first insulating layer is disposed on the second electrode side of the metal layer, and the second insulating layer is disposed on the light-emitting layer side of the metal layer; a first power source having a voltage between the first electrode and the second electrode; a second power source for applying a voltage between the metal layer and the second electrode having a polarity opposite to the polarity of the second electrode when a voltage is applied between the first electrode and the second electrode by the first power source; as well as A thin film transistor, the second electrode is connected to a drain electrode of the thin film transistor, the first electrode is connected to a source electrode of the thin film transistor, and the second power source is connected to the drain electrode or the source electrode.

3. The light-emitting element according to claim 1 or 2, It is characterized in that The first electrode is an anode, The second electrode is a cathode, The first power supply applies a voltage that makes the second electrode negative, The second power source applies a voltage that makes the second electrode positive.

4. The light-emitting element according to claim 1 or 2, It is characterized in that The first electrode is a cathode, The second electrode is an anode, The first power source applies a voltage that makes the second electrode positive, The second power supply applies a voltage that makes the second electrode negative.

5. The light-emitting element according to claim 1 or 2, It is characterized in that The thickness of the laminate is 20 nm or less.

6. The light-emitting element according to claim 5, It is characterized in that The thickness of the metal layer is less than 10 nm.

7. The light-emitting element according to claim 1 or 2, It is characterized in that The thickness of the first insulating layer is less than 5 nm.

8. The light-emitting element according to claim 1 or 2, It is characterized in that The thickness of the second insulating layer is less than 5 nm.

9. The light-emitting element according to claim 1 or 2, It is characterized in that The stacked body facilitates injection of charges from the second electrode into the light-emitting layer.

10. The light-emitting element according to claim 1 or 2, It is characterized in that A ratio of a voltage applied between the second electrode and the first electrode by the first power source to a voltage applied by the second power source is 80 or more and 120 or less.

11. The light-emitting element according to claim 1 or 2, It is characterized in that The metal layer reflects light from the light emitting layer.

12. The light-emitting element according to claim 2, It is characterized in that The second power source is connected to the drain electrode.

13. The light-emitting element according to claim 1 or 2, It is characterized in that The second electrode is made of an n-type semiconductor.

14. A method for controlling a light emitting element, The light emitting element include: a first electrode; a second electrode, which is opposite to the first electrode; a light-emitting layer disposed between the first electrode and the second electrode and comprising a phosphor; a laminate having a thickness capable of injecting charges from the second electrode into the light-emitting layer, and comprising a metal layer, a first insulating layer, and a second insulating layer, wherein the first insulating layer is disposed on the second electrode side of the metal layer, and the second insulating layer is disposed on the light-emitting layer side of the metal layer; a first power source having a voltage between the first electrode and the second electrode; as well as a second power source for applying a voltage between the metal layer and the second electrode, the polarity of which is opposite to the polarity of the second electrode when a voltage is applied between the first electrode and the second electrode by the first power source; The control method is characterized in that The following two periods are synchronized: a period during which the first power supply applies a voltage between the first electrode and the second electrode so that the second electrode becomes negative, and a period during which the second power supply applies a voltage between the metal layer and the second electrode so that the polarity of the second electrode becomes opposite to the polarity of the second electrode when the voltage is applied between the first electrode and the second electrode by the first power supply.

15. A method for controlling a light emitting element, The light emitting element include: a first electrode; a second electrode, which is opposite to the first electrode; a light-emitting layer disposed between the first electrode and the second electrode and comprising a phosphor; a laminate having a thickness capable of injecting charges from the second electrode into the light-emitting layer, and comprising a metal layer, a first insulating layer, and a second insulating layer, wherein the first insulating layer is disposed on the second electrode side of the metal layer, and the second insulating layer is disposed on the light-emitting layer side of the metal layer; a first power source having a voltage between the first electrode and the second electrode; as well as a second power source for applying a voltage between the metal layer and the second electrode, the polarity of which is opposite to the polarity of the second electrode when a voltage is applied between the first electrode and the second electrode by the first power source; The control method is characterized in that During a period when the first power supply applies a voltage between the first electrode and the second electrode and during a period when the first power supply does not apply a voltage between the first electrode and the second electrode, the second power supply applies a voltage between the metal layer and the second electrode having a polarity opposite to the polarity of the second electrode when the voltage is applied between the first electrode and the second electrode by the first power supply.

16. A method for controlling a light emitting element, The light emitting element include: a first electrode; a second electrode, which is opposite to the first electrode; a light-emitting layer disposed between the first electrode and the second electrode and comprising a phosphor; a laminate having a thickness capable of injecting charges from the second electrode into the light-emitting layer, and comprising a metal layer, a first insulating layer, and a second insulating layer, wherein the first insulating layer is disposed on the second electrode side of the metal layer, and the second insulating layer is disposed on the light-emitting layer side of the metal layer; a first power source having a voltage between the first electrode and the second electrode; as well as a second power source for applying a voltage between the metal layer and the second electrode, the polarity of which is opposite to the polarity of the second electrode when a voltage is applied between the first electrode and the second electrode by the first power source; The control method is characterized in that The second power source is an AC power source, During a period when the first power supply does not apply a voltage between the first electrode and the second electrode, the second power supply applies a voltage between the metal layer and the second electrode so that the polarity of the second electrode becomes the same as the polarity of the second electrode when the voltage is applied between the first electrode and the second electrode by the first power supply.

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