KR101768155B1 - Organic Light-Emitting Field-effect Transistors and Manufacturing Method Thereof - Google Patents

Abstract

The present invention relates to a semiconductor device, Organic film; And an organic light-emitting transistor including a source electrode and a drain electrode, wherein the electron transport layer of the organic film comprises an N, N'-ditridecylphenylene-3,4,9,10-tetracarboxylic diimide compound, The hole transport layer is characterized in that it contains a copper phthalocyanine compound. Thus, not only the field mobility and the movement of holes and electrons are well balanced in air but also the stability is further improved.

Description

[0001] The present invention relates to an organic light-emitting transistor and a method of manufacturing the same,

The present invention relates to an organic light emitting transistor and a method of manufacturing the same.

Organic semiconductor electronic devices are one of the most advanced IT technologies that can provide application concepts completely different from existing inorganic semiconductor based devices. Unlike inorganic semiconductors, such organic semiconductors can be manufactured at a low temperature / low cost and have excellent flexibility and ease of chemical structural change, and are used in various business fields. Particularly in the case of organic light-emitting diodes (OLEDs), the OLED display is adopted as a high-quality display in a main window of a mobile phone or a small screen and a TV screen of various mobile devices.

In general, a flat panel display panel is a device having a flat front panel using a characteristic of emitting visible light. When a strong voltage is applied between two electrodes, a gas discharge occurs between the electrodes, and ultraviolet rays generated at this time strike the phosphor A plasma display panel (PDP) using a phenomenon of emitting light, an electroluminescence display (FED) in which electrons emitted from a cathode formed in a plane collide against a phosphor, a filament is applied with a voltage to generate a thermoelectron , A vacuum fluorescent display (VFD) for displaying information by causing electrons to accelerate from a grid (Grid) to reach an anode and hit the phosphor that has already been patterned and emit light, a fluorescent or phosphorescent organic thin film And an organic light emitting display panel (OLED), which is a light emitting type in which light is generated while electrons and holes are coupled in the organic layer, A liquid crystal display (LCD) that displays information by using a principle that a liquid crystal serves as a shutter and transmits or blocks light according to switching of a voltage as a display applied to a display device, which is an intermediate state between a liquid and a solid, (LCD).

On the other hand, as a driving method for driving the organic EL element, an active matrix type field effect transistor (FET) using a thin film transistor (TFT: Thin Film Transistor) is effective in terms of operation speed and power consumption . On the other hand, semiconductor materials constituting thin film transistors have been studied not only for inorganic semiconductor materials such as silicon semiconductors and compound semiconductors but also for organic thin film transistors (OTFTs) using organic semiconductor materials. The organic semiconductor material is expected as a next-generation semiconductor material, but has a problem of lower charge mobility and higher resistance than an inorganic semiconductor material.

On the other hand, as for the field effect transistor, the channel width of the transistor can be shortened in an electrostatic induction transistor (SIT: Static Induction Transistor) of the vertical field effect transistor structure having the vertical structure, It is possible to realize a high-speed response and a large power, and it is difficult to be affected by an interface. Therefore, recently, an organic light emitting transistor having such an electrostatic induction transistor structure and an organic EL element structure combined with each other has been developed utilizing the above-described advantage of the electrostatic induction type transistor (SIT).

Specifically, organic light-emitting transistors (OLEDs) and OLEDs (OLEDs) and OTFTs function simultaneously, and since the luminescence phenomenon is reported when driving in a tetracene-based TFT in 2003, OLEFETs have been actively studied to date because of their attractiveness with multiple functions. OLEFETs are generally useful both in the basic research of organic electronic materials and devices and in the development of technical applications by adopting the lateral conduction channel structure of OTFTs and based on the light emitting mechanism by recombination of electrons and holes that are the same as OLEDs. OLEFETs can provide an excellent evaluation system for studying physical processes such as charge carrier injection, transfer and electroluminescence in organic semiconductors intuitively because the luminescence phenomenon is expressed in the transverse channel structure. Since OLEFET is a highly integrated device capable of controlling the luminescence phenomenon, it can be also applied to the development of an active matrix full-color electroluminescent display or the development of a variable type organic laser device.

Korean Patent Publication No. 10-2010-0127072

SUMMARY OF THE INVENTION The present invention has been conceived to solve the problems described above, and it is an object of the present invention to provide an organic electroluminescent device including an electron transport layer and a hole transport layer formed on a substrate, And to provide an organic light emitting transistor having improved balance.

Another object of the present invention is to provide a method of manufacturing the organic light emitting transistor capable of mass production.

According to another aspect of the present invention, there is provided a semiconductor device comprising: a gate electrode formed on a lower portion of a substrate;

An organic film formed on the substrate; And

And a source electrode and a drain electrode formed on the organic film,

Wherein the organic layer includes an electron transport layer and a hole transport layer which are sequentially stacked from the bottom,

Wherein the electron transport layer comprises an N, N'-ditridecylphenylene-3,4,9,10-tetracarboxylic diimide compound and the hole transport layer comprises a copper phthalocyanine compound do.

Also, the thickness of the electron transporting layer is 100 to 120 ANGSTROM, and the thickness of the hole transporting layer is 270 to 290 ANGSTROM.

Wherein the substrate is an n-type silicon substrate or a plastic substrate.

And an insulating layer between the substrate and the organic layer.

The insulating layer is formed by sequentially laminating a first insulating layer containing silicon dioxide and a second insulating layer containing PMMA.

The first insulating layer has a thickness of 1000 to 3000 ANGSTROM and the second insulating layer has a thickness of 200 to 400 ANGSTROM.

Wherein the source electrode includes a plurality of first branches formed in a comb shape extending from the one end at predetermined intervals,

And the drain electrode includes a second branch which extends in a comb shape at a predetermined interval and extends toward one end of the source electrode, the second branch being arranged in a direction of the first branch.

The width (d) of the source electrode and the drain electrode is 14.25 mm, and the length (t) of the source electrode and the drain electrode is 100 to 200 mu m.

Wherein a distance L between the first branch and the second branch is 150 占 퐉 and a length h of the first branch and the second branch is 3.85 mm; The distance b between the drain electrodes is 150 占 퐉, and the width a of the first branch and the second branch is 150 占 퐉.

According to another aspect of the present invention, there is provided a method of manufacturing a semiconductor device, comprising the steps of: i) forming a gate electrode under the substrate;

Ii) forming an insulating layer including PMMA on the substrate on which the gate electrode is formed;

Iii) inserting the substrate into a cluster beam deposition chamber including a first crucible with a first nozzle and a second crucible with a second nozzle;

(Iv) adding N, N'-ditridecylperylene-3,4,9,10-tetracarboxylic diimide (N, N'-ditridecylperylene- Depositing an electron transport layer on the substrate by supplying the vaporized compound into the cluster beam deposition chamber through the first nozzle;

And v) a copper phthalocyanine compound is placed in the second crucible and heated by a voltage application method to vaporize the vaporized compound, and the vaporized compound is supplied into the cluster beam deposition chamber through a second nozzle, Depositing a hole transport layer; And

And (vi) forming a source electrode and a drain electrode on the hole transport layer.

Wherein the substrate comprises an n-type silicon substrate; Or a plastic substrate.

And a dielectric layer made of silicon dioxide (SIO2) between the substrate and the insulating layer.

The temperature of the first crucible is 250 to 290 ° C, and the temperature of the second crucible is 280 to 300 ° C.

The thickness of the electron transporting layer is 100 to 120 ANGSTROM, and the thickness of the hole transporting layer is 270 to 290 ANGSTROM.

The deposition rate of the electron transport layer is 1.0 to 2.0 Å / s, and the deposition thickness of the hole transport layer is 0.1 to 0.3 Å / s.

A voltage of 6 to 10 V is applied in step iii), and a voltage of 10 to 12.5 V is applied in step iv).

The organic luminescent transistor of the present invention comprises an N, N'-ditridecylphenylene-3,4,9,10-tetracarboxylic diimide compound and a copper phthalocyanine compound as an electron transport layer and a hole transport layer, Not only the mobility and the movement of holes and electrons were well balanced, but the stability was further improved.

In the future, the organic light emitting transistor can more easily provide a motive for developing a driving circuit.

1 is a cross-sectional view of an organic light emitting transistor according to a preferred embodiment of the present invention.
FIG. 2 is a view illustrating a source electrode and a drain electrode of an organic light emitting transistor according to a preferred embodiment of the present invention.
3 is a cross-sectional view of a vaporizing apparatus according to the present invention.
4 is a graph showing the output characteristics of an organic light emitting transistor including a SiO ₂ / PMMA insulating layer according to a preferred embodiment of the present invention.
5 is a graph showing transfer characteristics of a P13 / CuPc organic light emitting transistor including a PMMA insulating layer according to a preferred embodiment of the present invention. The graph shows the light emitting section and the optical luminescence together.
6 is a diagram illustrating a reaction mechanism of light emitted from the organic light emitting transistor according to the present invention.
7A and 7B are graphs showing gate characteristics of an organic light emitting transistor according to a comparative example of the present invention.
FIG. 8 is a graph illustrating output characteristics of an organic light emitting transistor manufactured according to a comparative example of the present invention as a function of thickness of an electron transport layer. FIG.
9 is a graph showing transfer characteristics measured according to the thickness variation of the electron transport layer in the organic light emitting transistor manufactured according to the comparative example of the present invention. The graph shows the light emitting section and the optical luminescence together.
10 is a photograph of a mask used for forming the source electrode and the drain electrode.

BRIEF DESCRIPTION OF THE DRAWINGS The objectives, specific advantages and novel features of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: FIG. It should be noted that, in the present specification, the reference numerals are added to the constituent elements of the drawings, and the same constituent elements are assigned the same number as much as possible even if they are displayed on different drawings. Also, the terms "first "," second ", and the like are used to distinguish one element from another element, and the element is not limited thereto. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the following description of the present invention, detailed description of related arts which may unnecessarily obscure the gist of the present invention will be omitted.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a cross-sectional view of an organic light emitting transistor according to a preferred embodiment of the present invention.

As shown in FIG. 1, an organic light emitting transistor according to an embodiment of the present invention includes a gate electrode 110 formed on a lower portion of a substrate 120; An organic layer 140 formed on the substrate 120; And a source electrode 150 and a drain electrode 160 formed on the organic layer 140. The organic layer 140 includes an electron transport layer 141 and a hole transport layer 142 sequentially stacked from the bottom, And the hole transport layer 142 is formed of a copper phthalocyanine compound, and the electron transport layer 141 is formed of N, N'-ditridecylphenylene-3,4,9,10-tetracarboxylic diimide compound, (100). ≪ / RTI >

The organic light emitting transistor 100 according to the present invention is an organic electronic device used in an important role in the next generation active type organic light emitting display industry and includes a gate electrode 110, a substrate 120, an organic film 140, a source and a drain electrode 150, and 160, respectively.

The organic layer 140 may further include an insulating layer 130 between the substrate 120 and the organic layer 140. The organic layer 140 may be a layer made of an insulator for blocking electric current so that an electric field is applied to the organic layer 140 . Specifically, the insulating layer 130 is formed on one surface of the substrate 120 so as to cut off the current even if a gate voltage is applied.

Here, the substrate 120 may be an n-type silicon substrate. At this time, the substrate 120 is used as an input electrode to apply a gate voltage. However, the substrate 120 is not limited to the n-type silicon substrate, but may be a plastic substrate. Such a plastic substrate may be formed of a material selected from the group consisting of polyethersulphone (PES), polyacrylate, polyetherimide (PEI), polyethyelenen napthalate (PEN), polyethyeleneterephthalate (PPS), polyarylate (PAR), polyimide (PI), polycarbonate (PC), cellulosic triacetate (TAC), and cellulose acetate propionate propinonate, CAP). Meanwhile, the organic light emitting transistor according to the present invention may further include a gate electrode 110 disposed on the other surface of the substrate 120 to apply a gate voltage when the substrate 120 is a plastic substrate.

The insulating layer 130 is formed between the substrate 120 and the organic layer 140 and includes a first insulating layer (not shown) including silicon dioxide 131 and a second insulating layer 132 including PMMA are stacked in this order.

At this time, preferably, the first insulating layer 131 has a thickness of 1000 to 3000 ANGSTROM, and the second insulating layer 132 has a thickness of 200 to 400 ANGSTROM. If the thickness of the second insulating layer 132 is less than 200 ANGSTROM, pinholes may be formed in the insulating layer 130, which may interfere with the field effect, There is a problem that a higher voltage needs to be applied to the gate.

The electron transport layer 131 includes an N, N'-dioctyl-3,4,9,10-perylenedicarboximide compound as an n-channel transistor, which is a p-type material such as pentacene, tetracene, Thiophene oligomer and other common hole transporting layers, the n-type transistor has excellent electric field mobility, and the energy difference between HOMO and LUMO is well matched with other p-type materials, It is a suitable material for the mechanism. Furthermore, it exhibits significantly improved electric field mobility as compared with the use of Alq3, TCNQ, etc. generally used for n-type materials.

A hole transport layer 132 containing copper phthalocyanine (Copper (II) phthalocyanine) compound is formed in the p-channel transistor on the electron transport layer 131. When the compound is used, pentacene, tetracene, MEH -PPV, BP3T, rubrene and the like are excellent in compatibility with the N, N'-dioctyl-3,4,9,10-perylenedicarboximide compound used in the electron transport layer of the present invention as described above, The degree of improvement is remarkably improved. Also, since the N, N'-dioctyl-3,4,9,10-perylenedicarboximide compound and the copper phthalocyanine compound are provided as the electron transporting layer 131 and the hole transporting layer 132, And reliability is improved even at a high temperature.

The electron transport layer 131 may have a thickness of 100 to 120 ANGSTROM and the hole transport layer 132 may have a thickness of 270 to 290 ANGSTROM. Specifically, when copper phthalocyanine is used for the hole transport layer 132, the operation stability is increased, but a problem of having a high operating voltage may occur, and a balance between the flow rate of holes and electrons may collapse, . However, if the balance between the electron transporting layer 131 and the hole transporting layer 132 is matched well, copper phthalocyanine is merely inserted into the hole transporting layer, light emission and dipole magnetism become strong, operation stability is excellent, Characteristics such as low operating voltage, operating stability, lifetime, heat resistance, and yield are improved.

Therefore, when the thicknesses of the electron transporting layer 131 and the hole transporting layer 132 are less than the above range or slightly exceeding the above range, the flow speed of holes and electrons between the electron transporting layer 131 and the hole transporting layer 132 The light-emitting layer 132 is formed by using N, N'-dioctyl-3,4,9,10-peryldicarboxylic acid compound as the electron transporting layer 131 and a copper phthalocyanine compound as the hole transporting layer 132 There is a problem that the presence or absence of light emission and heat resistance can not be achieved. This was confirmed in the experimental example.

FIG. 2 is a view showing a source electrode 150 and a drain electrode 160 of the organic light emitting transistor 100 according to a preferred embodiment of the present invention. According to the source electrode 150 and the drain electrode 160, And a plurality of first branches (151) extending at predetermined intervals, wherein the drain electrode (160) extends in a comb shape at a predetermined interval to one end of the source electrode, And a second branch 161 disposed substantially opposite to the first branch 161.

The source electrode 150 and the drain electrode 160 may be made of gold (Au).

The width d of the source electrode 150 and the drain electrode 160 may be 14.25 mm and the length t of the source electrode and the drain electrode may be 100 to 200 mm.

Wherein a distance L between the first branch and the second branch is 150 占 퐉 and a length h of the first branch and the second branch is 3.85 mm; The distance b between the drain electrodes is 150 占 퐉, and the width a of the first branch and the second branch is 150 占 퐉. The charge injection and charge transfer through the source-drain electrode having such a zigzag structure are effectively performed, so that not only electric characteristics are improved but also high transparency.

On the other hand, when a voltage of 0 to 60 V is applied to the gate electrode and a voltage of 60 V is applied to the drain electrode of the transistor of the present invention, + charge is generated in the gate and holes are deposited in the copper phthalocyanine layer. The electrons in the N, N'-ditridecylphenylene-3,4,9,10-tetracarboxylic diimide are induced by the holes to be laminated, and holes and electrons are recombined to generate light. Since the energy difference of copper phthalocyanine (Copper (II) phthalocyanine) is 1.7 eV and the concentration of N, N'-ditridecylphenylene-3,4,9,10-tetracarboxylic diimide is 2.0 eV, it is formed at the copper phthalocyanine interface The excitons are not absorbed by the N, N'-ditridecylphenylene-3,4,9,10-tetracarboxylic diimide layer, and emit light outside the electrode.

As a result, the organic light emitting transistor of the present invention having the above structure forms an electron transporting layer and a hole transporting layer by using a specific compound. Therefore, compared with the case of using a conventional compound, The N, N'-ditridecylphenylene-3,4,9,10-tetracarboxylic diimide compound used in the electron transport layer is easily degraded when exposed to air, N, N'-ditridecylphenylene-3,4,9,10-tetracarboxylic diimide is formed on the lower layer and the PMMA insulation layer is used to increase the stability of the device. It is expected to be easy.

According to another aspect of the present invention,

I) forming a gate electrode under the substrate;

Ii) forming an insulating layer including PMMA on the substrate on which the gate electrode is formed;

Iii) inserting the substrate into a cluster beam deposition chamber including a first crucible with a first nozzle and a second crucible with a second nozzle;

(Iv) adding N, N'-ditridecylperylene-3,4,9,10-tetracarboxylic diimide (N, N'-ditridecylperylene- Depositing an electron transport layer on the substrate by supplying the vaporized compound into the cluster beam deposition chamber through the first nozzle;

And v) a copper phthalocyanine compound is placed in the second crucible and heated by a voltage application method to vaporize the vaporized compound, and the vaporized compound is supplied into the cluster beam deposition chamber through a second nozzle, Depositing a hole transport layer; And

And (vi) forming a source electrode and a drain electrode on the hole transporting layer,

3, the substrate holder 230 is fixed on the inner upper side of the vacuum chamber, and a substrate (not shown) on the lower side of the substrate holder 230 is fixed to the support base 201 Two crucibles 202 and 203 having heating wires as heating means are disposed on the upper portion of the crucible 202 and a cover having a nozzle is formed on the crucibles 202 and 203 so that the crucibles 202 and 203 And the organic material to be deposited is placed in each of them. In addition, the thickness monitor 200 installed for measuring the thickness of the deposited organic organic thin film has a deposition rate and a thickness of the deposited organic material expressed in units of Å / s and k Å, respectively, and the thickness of the thin organic layer can be monitored, . The shutter 210 is disposed between the substrate and the crucibles 202 and 203 so that the shutter 210 can be opened and closed from the outside. The shutter 210 is initially closed to prevent deposition of undefined impurities, When it reaches it, it is provided so that it can be rotated and opened from the outside.

Next, a method of manufacturing the organic light emitting transistor of the present invention will be described in more detail. In step i), a step of forming a gate electrode (or an input electrode) And is not particularly limited so long as it is a commonly used method. The substrate that can be used in this case may be an n-type silicon substrate or a polyether sulfone (PES), a polyacrylate (PAR), a polyetherimide (PEI), a polyethyelenen naphthalate (PEN) (PET), polyethyeleneterepthalate (PET), polyphenylene sulfide (PPS), polyallylate, polyimide, polycarbonate (PC), cellulose triacetate (TAC) and cellulose acetate propionate And cellulose acetate propinonate (CAP). The ⅰ) step since, preferably, it may further include forming a first insulating layer made of silicon dioxide (SiO ₂₎ formed by the thermal oxidation the surface of the silicon substrate, the first insulating layer thickness of May preferably be 1000 to 3000 ANGSTROM.

The first insulating layer may be formed by spin coating a solution containing silicon dioxide on a substrate.

Next, in step ii), an insulating layer including PMMA is formed on the substrate. Specifically, the PMMA solution is deposited on the first insulating layer or the substrate using a solution process. The PMMA polymer material may be mixed with a toluene solution to prepare the PMMA solution. At this time, the mixing volume ratio of the toluene solution to the PMMA polymer material may be 1: 90-100. Then, the PMMA solution was spin-coated at 6000 rpm for 60 seconds and deposited on the substrate. Then, the PMMA solution was heated to 100 to 140 ° C in a vacuum oven for 2 hours, And then cooled. The thickness of the second insulating layer may preferably be 200 to 400 ANGSTROM.

Next, in step iii), the substrate is inserted into a cluster beam deposition chamber including a first crucible having a first nozzle and a second crucible having a second nozzle. Specifically, the material of the crucible may be selected from the group consisting of N, N'-dioctyl-3,4,9,10-perylenedicarboximide (N, N'-dioctyl- When the compound is heated or heated, it is preferable to use graphite which can be heated at a high temperature and has little thermal deformation even at a high temperature. In addition, although the shape of the crucible is not particularly limited as long as it can be provided with a lid having a nozzle on the top thereof, it is advantageous to form a thin film by spin coating. Meanwhile. The nozzle is a passage through which the compounds sublimate and is discharged toward the substrate, and the diameter thereof may preferably be 0.5 to 1.5 mm. If the diameter of the nozzle provided in the crucible is less than 0.5 mm, the clustered vapor particles described later are difficult to pass through the nozzle. If the diameter exceeds 1.5 mm, the cluster molecules become too large, It is not preferable because it is difficult to form. Therefore, the kinetic energy generated when passing through a nozzle having a diameter of 0.5 to 1.5 mm can supply energy necessary for migration to form a uniform thin film. Therefore, it is advantageous in that it can be deposited at room temperature without being heated in the deposition step by the moving energy.

Next, as the step iv), the N, N'-dioctyl-3,4,9,10-perylenedicarboximide compound is added to the first crucible And the vaporized compound is supplied into the cluster beam deposition chamber through the first nozzle to deposit an electron transport layer on the substrate.

In the present invention, N, N'-dioctyl-3, 4, 9, 10-perylenedicarboximide compound is used as a main component of an electron transport layer deposited on an organic light emitting transistor. This compound is superior in the electric field mobility of an n-type transistor as compared with a compound used for forming a hole transporting layer such as pentacene, tetracene and thiophene oligomer, which are p-type materials. Generally, it exhibits remarkably improved electric field mobility as compared with the case of using Alq3, TCNQ, etc. used for n-type materials. Particularly, by using the PMMA insulating layer, it is possible to prevent penetration of moisture on the surface of silicon dioxide, so that the n-type electric field mobility can be improved and a stable element can be formed in the air.

For this, a voltage of 4.5 to 9.5 V is preferably applied. If a voltage less than 4.5 V is applied, the organic material may not sublimate and the deposition may not be performed smoothly. If the voltage is higher than 11.5 V, the deposition rate may not be controlled.

On the other hand, when the N, N'-dioctyl-3,4,9,10-perylenedicarboximide compound is heated in a vacuum state, the compound is sublimated into a gas by phase change and the sublimed compound particles flow inside the first crucible do. The particles that flow are passed through a nozzle formed on the upper part of the crucible. Since the particles pass through a small hole of the nozzle, only the particles moving in the upward direction, that is, in a state having kinetic energy in one direction, It becomes possible to pass. Therefore, the particles vaporized inside the crucible flow inside the crucible and hit each other, forming a cluster with a weak intermolecular attraction, and only the clusters having an upward directed direction have a uniform and constant kinetic energy, Passes through the nozzle in the form of a beam, and proceeds toward the inner upper side of the vacuum chamber. The clusters having upward directionality and uniform and constant kinetic energy at the same time collide with the lower part of the substrate disposed on the inner upper side of the vacuum chamber and the weak intermolecular attractive force of the cluster is broken by the collision, The thin film is finally deposited in the vicinity of the vacant space collided by the energy, so that the thickness of the thin film becomes uniform, and the crystallinity is excellent.

On the other hand, according to the conventional physical vapor deposition (PVD) method or the OMBD method, the organic molecules to be deposited have specific orientation and do not move in a vacuum chamber, but a plate-shaped or bowl- A phenomenon of direct evaporation to a surrounding environment in a vacuum state occurs. This is different from clusters in the cluster beam deposition according to the present invention, in which organic molecules are clustered due to weak attraction. That is, organic molecules having kinetic energy of a wide distribution size with various directions of orientation in a vacuum state are sublimated. Therefore, particles with a wide range of kinetic energy are deposited in many directions from many directions, so that the surface of the substrate has a rough island shape. Therefore, the surface of the organic molecules to be deposited becomes coarse, and the crystalline is lowered, thereby reducing the electric field mobility.

Meanwhile, the temperature of the first crucible may preferably be 250 to 290 ° C. If the internal temperature of the first crucible is lower than 250 ° C, the compound is not easily vaporized and it is difficult to form an organic thin film because it can not supply sufficient energy required for thermal polymerization in a flat substrate. The chemical composition of the material forming the thin film may be a modified form and the roughness of the surface becomes poor.

Then, the clusters are deposited on the dielectric layer to form an electron transport layer. Specifically, the cluster that has sublimated and passed through the nozzle of the crucible advances to the inner side of the vacuum chamber and collides with the lower portion of the substrate. The collided clusters break the weak intermolecular bonding force and become originally sublimated organic particles and move to the vacant space around and join with the substrate. In addition, the surfactant can be deposited on the surface of the substrate before depositing the clusters. When the compound is used, the thickness may be 100 to 120 Å. When the deposition rate is less than 1.0 ANGSTROM, the deposition rate of the thin film is too slow, so that it is difficult to form the organic thin film properly. When the deposition rate is more than 2.0 ANGSTROM, The roughness of the organic thin film may be poor.

On the other hand, it is preferable not to heat the substrate at the time of cluster beam deposition, more preferably, the vaporized cluster can be deposited at room temperature of 20 to 30 DEG C to form an organic film. If the substrate is heated, the production cost required for heating is increased, and it is difficult to establish the temperature uniformity of the entire substrate as a process condition in accordance with the increase in size.

Next, as step (v)), a compound of copper phthalocyanine (Copper (II) phthalocyanine) is placed in the second crucible and heated by a voltage application method to vaporize the vaporized compound, and the vaporized compound is subjected to the cluster beam deposition And copper phthalocyanine is deposited to form a hole-forming layer on the electron-transporting layer by supplying the hole-transporting layer into the chamber. At this time, the conditions such as the material of the second crucible used, the thickness of the nozzle, and the like are the same as those in step iv), and therefore, the following description will focus on the parts different from step iv).

On the other hand, the temperature of the second crucible may preferably be 280 to 300 ° C. If the internal temperature of the second crucible is lower than 280 ° C, the compound is not easily vaporized and the hole transport layer is difficult to form because it can not supply sufficient energy required for thermal polymerization in a flat substrate, The chemical composition of the material forming the thin film may be a modified form and the roughness of the surface becomes poor.

When the compound is used, the thickness of the hole transporting layer may be 270 to 290 ANGSTROM. If the thickness is less than 270 Å or exceeds 290 Å, the electrical characteristics may be deteriorated. When the deposition rate is less than 0.1 ANGSTROM, the deposition rate of the thin film is too slow, so that it is difficult to form the organic thin film properly. When the deposition rate is more than 0.3 ANGSTROM, The roughness of the hole transport layer may be poor. Also, in step iv), a voltage of 10.0 to 12.5 V may be applied to vaporize the compound.

Meanwhile, steps iv) and v) may be performed sequentially. In the present invention, a hole transporting layer is formed after forming an electron transporting layer. This is because the perylene material used as the electron transporting layer is easily deteriorated when exposed to air, so that exposure to air is prevented by intentionally forming the perylene material for stability of the device.

Next, in step (vi), a source electrode and a drain electrode are formed on the hole transport layer. The channel width of the source electrode and the drain electrode of the p-type transistor formed in the step iv) is preferably 17 to 19 mm, and the channel length may be And may be 100 to 200 탆.

Hereinafter, the present invention will be described in more detail with reference to preferred embodiments of the present invention, but the present invention is not limited thereto.

< Example  1>

1- (1) Gate electrode formation

A gate electrode having a thickness of 2000 angstroms was formed on the bottom of the cleaned n-type silicon substrate using aluminum (Al).

1- (2) Insulating layer  formation

Silicon dioxide (SiO ₂ ) was deposited at a thickness of 2000 Å on the substrate having the gate electrode formed thereon by a thermal oxidation method. Thereafter, a PMMA insulating layer was deposited to a thickness of 200 to 400 ANGSTROM on the silicon substrate using a spin coating method. The PMMA polymer material was spin-coated in toluene at a volume ratio of 1% at 6000 rpm for 60 seconds and heated to 120 ° C in a vacuum oven for 2 hours And then cooled to room temperature.

1- (3) electron Transport layer  deposition

The vacuum degree in the vacuum chamber was maintained at 1 × 10 ^-5 Torr on average using a 10-inch diffusion pump with a baffle, and graphite having a cover with a nozzle having a diameter of 1 mm formed on the top ) Material was placed on the inner lower side of the vacuum chamber, and the n-type silicon substrate was placed on the inner upper side of the vacuum chamber with the silicon dioxide laminated side down. At this time, the distance between the n-type silicon substrate and the first crucible was 190 mm. Next, N, N'-ditridecylphenylene-3,4,9,10-tetracarboxylic diimide is introduced into the first crucible and the deposition temperature is 250 to 290 ° C, An electron transport layer having a thickness of 100 to 120 angstroms was deposited under the condition of 2.0 A / sec. Here, the temperature of the substrate temperature was maintained at 20 占 폚.

1- (4) hole Transport layer  deposition

Copper phthalocyanine was injected into the second crucible and a voltage of 6 to 12.5 V was applied to deposit an electron transporting layer having a thickness of 270 to 290 Å at a heating temperature of 300 ° C and a deposition rate of 0.1 to 0.3 Å / sec.

1- (5) source and drain  Electrode formation

Next, gold (Au) is made of an electrode material and the thickness of the thin film is 500 angstroms, the width d of the source and drain electrodes is 12 to 19 mm, the length t of the source and drain electrodes is 100 A source electrode and a drain electrode were simultaneously formed by a vacuum vapor deposition method using a shadow mask having a thickness of 200 [mu] m to fabricate an organic light emitting transistor.

< Example  2>

An organic light emitting transistor was manufactured in the same manner as in Example 1 except that the 1- (3) step and the 1- (4) step were performed at the same time.

< Comparative Example >

An organic light emitting transistor was manufactured in the same manner as in Example 1 except that the thickness of the electron transporting layer was 150 ANGSTROM and the thickness of the hole transporting layer was 280 ANGSTROM.

< Experimental Example >

The bipolar organic light emitting transistor manufactured in Example 1 was measured for its electrical characteristics in air, and is shown in FIGS. 4, 5, 6, 7A and 7B and Table 1.

Classification
(thickness) μ _eff ^{ε, avg} ± σ
(cm ² / Vs) V _T ^e
(V) μ _eff ^{h , avg} ± σ
(cm ² / Vs) V _T ^h
(V) V _DS
(V) CuPc
(500 A) - - 1.1 × 10 ^-2
± 2.4 × 10 ^-3 - 5.5
± 2.9 - 60 P13
(500 A) 1.02 x 10 ^-1
± 3.8 × 10 ^-2 16.0
± 5.4 - - + 60 P13 / CuPc
(110 A / 280 A) 3.13 x 10 ^-2
± 0.18 × 10 ^-2 25.3
± 4.6 5.56 × 10 ^-3
± 0.19 × 10 ^-3 - 10.2
± 8.9 ± 60

4 is a graph showing a drain sweep curve of a typical bipolar organic light emitting transistor, showing how holes and electrons move according to the voltage of a gate. For example, when a negative voltage is applied to V _DS , it can be seen that electrons are injected preferentially when the gate voltage is 0 V. As the negative voltage of the gate becomes larger, the role of holes appears.

The value of the gate sweep curve, that is, the electric field mobility (μFET, cm 2 / Vs), the current blinking ratio (ION / OFF), and the threshold voltage (V _T , V) Can be derived by Equation (1). The graph shows that the flow rates of holes and electrons are well-balanced. Also, the intensity of light increases as the positive voltage increases. In the present invention, a graph comparing the presence or absence of light emission and the characteristics of the dipole magnetic property according to the thicknesses of specific holes and electron transporting layers is added. As a comparative example, an organic light emitting transistor having an electron transporting layer having a thickness of 150 ANGSTROM was used in the graph. 7A and 7B specifically show that the influence of the electron transporting layer is greater than the hole transporting layer for the above reasons.

As described above, the flow velocity of the holes and electrons must be well balanced to increase the intensity of light. In the case of the comparative example, it was confirmed that since the n-type transistor is influential, the balance of the dipole magnetism is not well balanced and weak light is generated as compared with the optimized thickness of the present invention (Fig. 7) And the thickness of the hole transport layer are very important. This is an effect that can not be obtained through a simple repetitive experiment.

[Equation 1]

In Equation (1), L is the width (mu m) of the channel between the drain and source, IDS is the current flowing between the source and drain electrodes, W is the length of the channel between the source and drain electrodes, Ci is silicon dioxide And the unit is nF / cm ² . VGS is the voltage (V) between the source and gate electrodes and VT is the threshold voltage.

FIG. 8 is a graph showing the output characteristics of the organic light emitting transistor according to the variation of the thickness of the electron transport layer according to the comparative example of the present invention. According to this graph, when the thickness of the electron transport layer P13 is 150 ANGSTROM It was confirmed that the phenomenon of low light emission due to the decrease of the double polarity and the saturation of the (+) direction in the graph were confirmed.

9 is a graph showing transfer characteristics measured according to the thickness variation of the electron transport layer in the organic light emitting transistor manufactured according to the comparative example of the present invention. The graph shows the light emitting section and the optical luminescence together.

In the gate sweep graph of FIG. 9, in which the ambipolar characteristics can be easily confirmed, it was confirmed that the N-type thickness more affects the electrical characteristics of the organic light emitting transistor than the p-type.

That is, when the thickness of the electron transporting layer is 150 ANGSTROM, the light intensity of the organic light emitting transistor in the gate sweep graph is significantly reduced.

In other words, various semiconductor materials have been provided through research and development of organic light emitting transistors in the past, and the light intensity and electrical characteristics are not enough to be industrialized. Accordingly, the present invention provides an improved effect, that is, an organic light emitting transistor which is superior to the conventional organic light emitting transistor by controlling the perfect balance of the electron and hole flow rates in the hole transporting layer of the electron transporting layer. In order to attain the balance, it was confirmed that a balance between the thicknesses of the electron transporting layer and the hole transporting layer is very important.

Therefore, in the present invention, when the electron transporting layer has a thickness of 100 to 120 ANGSTROM and the hole transporting layer 132 has a thickness of 270 to 290 ANGSTROM, It is confirmed that the emission of light and the dipole magnetism are remarkably stronger than those in the case of deviating from the range of the electron transporting layer and the hole transporting layer.

Therefore, the organic light emitting transistor of the present invention can obtain other improved effects such as heat resistance, yield and stability.

<Description of Symbols>

100: organic light emitting transistor 110: gate electrode

120: substrate 130: insulating layer

140: organic film 141: electron transport layer

142: hole transport layer 150: source electrode

160: drain electrode 151, 161: first branch, second branch

200: Monitor 201: Support

202: first crucible 203: second crucible

210: shutter 230: substrate holder

Claims (17)

A gate electrode formed on a lower portion of the substrate;
An organic film formed on the substrate; And
And a source electrode and a drain electrode formed on the organic film,
Wherein the organic layer includes an electron transport layer and a hole transport layer which are sequentially stacked from the bottom,
Wherein the electron transport layer comprises an N, N'-ditridecylphenylene-3,4,9,10-tetracarboxylic diimide compound, the hole transport layer comprises a copper phthalocyanine compound,
The thickness of the electron transporting layer is 100 to 120 ANGSTROM, the thickness of the hole transporting layer is 270 to 290 ANGSTROM,
The substrate is an n-type silicon substrate or a plastic substrate,
Wherein the insulating layer is formed between the substrate and the organic layer, and the insulating layer is formed by sequentially laminating a first insulating layer including silicon dioxide and a second insulating layer including PMMA,
The thickness of the first insulating layer is 2000 ANGSTROM, the thickness of the second insulating layer is 200 ANGSTROM to 400 ANGSTROM,
Wherein the source electrode includes a plurality of first branches formed in a comb shape extending at a predetermined interval from one end of the source electrode, the drain electrode extending toward one end of the source electrode at a predetermined interval in a comb shape, And a second branch staggered from the first branch,
Wherein the width d of the source electrode and the drain electrode is 14.25 mm, the length t of the source electrode and the drain electrode is 100-200 mu m, the distance L between the first branch and the second branch is 150 mu m, Wherein a length h of the first branch and the second branch is 3.85 mm, a distance b between the first branch extending from the source electrode and the drain electrode is 150 mu m, And the width (a) is 150 占 퐉. delete delete delete delete delete delete delete delete delete I) forming a gate electrode under the substrate;
Ii) forming an insulating layer on the substrate on which the gate electrode is formed, the insulating layer including 200 to 400 A thick PMMA;
Iii) inserting the substrate into a cluster beam deposition chamber including a first crucible with a first nozzle and a second crucible with a second nozzle;
(Iv) adding N, N'-ditridecylperylene-3,4,9,10-tetracarboxylic diimide (N, N'-ditridecylperylene- Depositing an electron transport layer on the substrate by supplying the vaporized compound into the cluster beam deposition chamber through the first nozzle;
And v) a copper phthalocyanine compound is placed in the second crucible and heated by a voltage application method to vaporize the vaporized compound, and the vaporized compound is supplied into the cluster beam deposition chamber through a second nozzle, Depositing a hole transport layer; And
Vi) forming a source electrode and a drain electrode on the hole transport layer,
Wherein the substrate comprises an n-type silicon substrate; Or a plastic substrate,
Forming a first insulating layer made of silicon dioxide (SiO2) having a thickness of 2000 Å by thermal oxidation on the surface of the silicon substrate after the i)
The temperature of the first crucible is 250 to 290 ° C, the temperature of the second crucible is 280 to 300 ° C,
The thickness of the electron transporting layer is 100 to 120 ANGSTROM, the thickness of the hole transporting layer is 270 to 290 ANGSTROM,
The deposition rate of the electron transport layer is 1.0 to 2.0 A / s, the deposition rate of the hole transport layer is 0.1 to 0.3 A / s,
Wherein a voltage of 6 to 10 V is applied in step (iii) and a voltage of 10 to 12.5 V is applied in step (iv). delete delete delete delete delete delete

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