JPS59101793A - Thin film electroluminescent element - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an IC film TR-luminescence device which is made of pyroxene and is driven at a low voltage.

Conventional thin film]-Rectroluminescence element (hereinafter referred to as “
The same L element has a cross section 4j11 as shown in FIG.
Pickled. A transparent electrode 14 made of ITO'C is placed on the top surface of the glass substrate 12, and an insulating layer 16a made of dielectric is placed on the top surface of the transparent electrode 14, and the luminescent center is roughly formed ('J
A luminescent layer made of one luminescent substance such as an activator and a coactivator that facilitates the introduction of the activator into the matrix is grown as a crystal. The upper end surface of the light emitting layer 18 is roughly covered with an insulating layer 16b, and the upper end surface of this insulating layer 16b is covered with an aluminum electrode 2.
0 is combined with ``c Ji''.
The L string consists of the above configuration. The "element" applies an AC voltage of a constant frequency between the aluminum electrode 20 of the first part and the transparent electrode 11 of the F part to accelerate the conducting electrons in the light emitting layer 18, and by inelastic collision, the impurity center When the excited Q17 lia is recombined with the impurity center, it emits energy and emits light. The dielectric insulating layer is made of a high dielectric constant material in order to apply a high voltage to the light emitting layer. For example, it is made of butane butybarium (BaTiO3) or a transparent insulating material. Substances such as yttoria (YzO3) and tantalum chloride (-(-azos)) are used. Then, a light-emitting I4 substance such as zinc sulfide is deposited on this insulating layer by CVD or I
Crystals are grown using the DVD method.

However, it is known that in order to increase the luminance of the device, it is necessary to improve the crystallinity of the light emitting layer. However, in the conventional technology, in order to improve the crystallinity of the light-emitting layer, the film thickness of the light-emitting layer is increased by using the J method, and in order to reduce the thickness of the light-emitting layer. 1q high brightness
However, it inevitably has the disadvantage that the driving voltage will be 80%.

Honmaru Akiban, 1, was developed to improve these conventional drawbacks, and by reducing the crystallinity of the light-emitting layer, the film thickness of the light-emitting layer can be made thinner, thereby achieving a predetermined luminescence. One point was to provide an L element that made it possible to lower the driving voltage to obtain brightness.

i! II) A silicon single crystal substrate with a plane orientation (1°'1.'l) having an N-junction layer, and a method for growing crystals on the silicon single crystal substrate. It consists of a U-shaped light emitting layer, an insulating layer laminated on the other end surface of the light emitting layer, and a transparent electrode placed on the insulating layer! l) From the thin film luctroluminescent element that collects the light emitting F, 7
A silicon single crystal is used as the substrate to facilitate crystal growth. In order to improve the crystallinity of the light-emitting layer, a silicon single crystal of the order (1, 1, 1) is used.
, the light-emitting layer f! I body trade C,
Zinc sulfide (711S). Both substances I; both belong to the cubic system, and the misfin 1~ between the lattice constants of a3 is as small as -0.44%. Here, Misfit 1~(X
) is the relationship between the lattice constant (13,) of the substrate material and the lattice constant <a) of the material on which the crystal is grown,
I can imagine that X=(a-b), /b. However, since a silicon single crystal substrate with a (1,1,1) plane orientation is used, the crystals of the light-emitting layer material grow in the (1,1°1) plane direction. It is easy to improve the crystallinity of the light emitting layer. Therefore, the monomer substance zns forming the luminescent layer is mi7'
J position (1, 1, 1) When the orientation is 01g, ii1 degree is the highest.

As mentioned above, the Ministry of the Invention et al.
1) Increase the crystallinity of the orientation/T, increase the dry crystallization 1 ((
We experimentally demonstrated that a (1,1,1) oriented silicon single crystal substrate is effective as an i-based substrate.
1, which completed the present invention, however, since the silicon:1 single crystal substrate is electrically conductive, the silicon:1 single crystal substrate is
When an electric current 97 is applied to a silicon single crystal substrate using an electrode, carriers are injected into the light emitting layer, and internal electric field type electroluminescence (J) does not occur. It is necessary to interpose an insulating layer between the fully bent electrodes, such as a silicon single crystal substrate.However, if this insulating layer is interposed, there will be no crystal growth during the crystal growth process, and on the insulating substrate, Silicon single crystal is faceted (1,1
, 1> is rotation. Therefore, a silicon single crystal substrate is used as an electrode, and there is no gap between the electrode and the silicon single crystal substrate! In order to maintain t'1, a PNN junction layer is deposited on the silicon single crystal substrate.
.

The second feature of the present invention is that 1) an N junction layer is provided on the silicon single crystal substrate. Using the junction layer IB of the PN junction layer, a DC bias in the opposite direction is always applied to this junction layer / J Yuno, and only a high frequency voltage is applied to the light emitting layer 81! The DC biased AC current 11 is applied to the N junction layer so that the current 11 in the opposite direction is always applied to the N junction layer. Ru. Therefore, the capacitance of the PN junction layer acts to block the jI current voltage component, and the PN junction layer has the effect of blocking the jI current voltage component, and the PN junction layer has the effect of blocking the −
21 people of F Tosu\7 do not occur.

As a result, it is possible to apply a high voltage, for example a high electric field of 10'V/cm, to the light emitting layer.

The above-mentioned ``L I-element'' according to the present invention was constructed.
Since f improves the crystallinity of the light emitting layer, the thickness of the light emitting layer can be made thinner in order to obtain the same brightness as the conventional one. 7cIfi) Since the film thickness is thin, it is possible to use a low driving voltage for emitting light. Furthermore, if you apply the same voltage as the conventional drive type,
The luminance of the light is slightly higher.

Hereinafter, the WJ structure and effects of the present invention will be explained in more detail based on specific examples of the present invention.

FIG. 2 shows a 4^1 diagram of a cross section of a thin film [1-raw material] according to a specific embodiment of the present invention. The silicon plate 30 is made of type 1 single crystal silicon.
It consists of a 1-30a crystalline silicon layer 1-30a and a υ-blast 30b made of N-type A-type crystalline silicon, forming 1) an N junction layer. N' type drawer rib tray 1-30 b
A light-emitting layer 332 is formed in a part of the light-emitting layer 332, in which the light-emitting host is zinc sulfide and the active agent is manganese and rare earth thread. A transparent insulating layer 34 is provided on the upper surface of the light emitting layer 32. This insulating layer is
), formed using silicon nitride (Si3N4) snow material. Furthermore, a transparent electrode made of an ITO thin film and an electrode made of several tens of gold thin films are tightly formed on the upper end surface of this transparent insulating layer.

The manufacturing method for this L Lua is as follows. Surface orientation (1
, 1', I) on the P-type silicon single crystal substrate 30a, an impurity substance Boshu C having a donor rank of 9 is deposited.
H1JA silane (Sil
14) Flow a gas and grow the N-type silicon single crystal glue 1 to 30 b in the vapor phase to form a 4-t P N junction layer. N!v!'s Shirin21n Krystal Noribus(・Leh
301) Place 81 layers of zinc sulfide on the top surface, and grow crystals of a light-emitting layer with manganese as the center of light emission by an electron beam M method. Layer 19 is 0.1-0.3 μm1. Furthermore, a transparent insulating layer made of ittria is placed on top of the light emitting layer 1.
．． A film of 1 μm thick was formed on the film by electron beam heating to a thickness of 2 to 0.5 μm, and then a transparent electrode made of Ru. Here (" the depth of the P N junction layer and the impurity depth Iα
(Required for non-emission (< Voltage resistance 11 is too high for humans, J, it is necessary to set it. L!', then P
This is because a single current binonous voltage is always applied to the N-junction layer.

Figure 3 shows a case in which zinc sulfide is grown on a conventional glass substrate [-] and a case in which a luminescent layer of zinc sulfide is grown on a single crystal silicon substrate oriented in the plane orientation (1,1,1>). ul
This study investigated the crystallinity of zinc sulfide in the case of . The crystallinity of the zinc sulfide was measured by the reflected intensity of X-rays. It is clear from this experiment that when zinc sulfide is crystal-grown on a single-crystal silicon substrate oriented in the (1,1,1) direction, which is one of the characteristics of the present invention, As a result, it can be seen that the product orientation 1'l is increased about 100 times as compared to the conventional glass substrate type ELffi.

From this, it can be seen that the light emitting screen 11 of the EL element according to the present invention is
Stomach 1! It is predicted that

FIG. 4 shows the light emission brightness of a specific example of the present invention when a driving voltage is applied to the L limit, and the luminance is compared with that of a conventional glass substrate type El element.

The circles in the figure indicate the luminescent layer formed on the glass substrate [Lffi
The properties of the light-emitting layer of zinc sulfide are expressed by the square mark μ on the (1,1,1)-oriented single crystal silicon substrate of the present invention.
In addition, there is C which shows the voltage-emission intensity characteristics of the device.

As is clear from this experiment, the EL element of the present invention has a saturated value of luminance compared to the glass substrate type.
It can be seen that the luminance is about 2.5 times higher. or,
Comparing the applied voltage at which the luminance is saturated, it is found that the brightness of the glass substrate is higher than that of the glass substrate [7. While the L output voltage is 230V, the L output voltage of the present invention is as low as 170V.

From this, the present invention [11] can reduce the driving voltage 11' compared to the conventional glass substrate type element, and can significantly improve the luminance.

Conversely, the thickness of the light-emitting layer is 1 even if it is several hundred large.
A sufficient luminescence aF degree was obtained.

In this way, the EL structure of the present invention can be realized by forming a P-N junction on a crystalline silicon 2,7 plate with a surface angle of <1.1°1).
Because the crystal growth of the light-emitting layer is uC, the crystal orientation of the light-emitting layer in the (1,1,1>:/j direction is very good. 7I! High degree?
do. In addition, it has been revealed that if the luminescent layer weighs just one loaf, the driving voltage is low (and the luminance is high).Furthermore, using a series °1 substrate as the 7.=L plate, Because of this, it is possible to create the circuit that drives the EL resistor in the same silicon single crystal and convert it into an IC.Furthermore, it is possible to use the conventional IC manufacturing technique. 1- It is possible to create a matrix-shaped light-emitting device using a single element and having light-emitting pixels similar to Miku L1.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a 4-11 structure of a conventional thin film electroluminescent device. FIG. 2 is a cross-sectional view showing the structure of a thin film electroluminescent device according to a specific embodiment of the present invention. Figure 3 shows the results of measuring the crystallinity of the light-emitting layer of the electroluminescent layer of the same example and of the W-film electroluminescent device fabricated on a conventional glass substrate. This is the experimental data for comparison.Figure 4 shows the electroluminescent element of the same example and the luminescent luminescence characteristics with respect to the applied voltage in the correct 1-1 luminescence (with a luminescent layer installed on the glass substrate). There are some things I've looked into. 12...Glass substrate 14...Transparent rod 1G...
・Insulating layer 18...Light emitting layer 20...Metal electric V
i 30...Silicon substrate 32...Light emitting Fi
34...Transparent insulating layer 33G...Metal electrode Fig. 1 Fig. 2

Claims (2)

[Claims] (1) A silicon single-crystal substrate with a plane orientation (,1,1,1>) that faces the PN junction layer, a light-emitting layer that is crystal-grown on the silicon single-crystal substrate, and the other end surface of the light-emitting layer. A 'Fi91I!11 electroluminescent device is characterized in that it consists of an insulating layer laminated on the insulating layer, and a transparent electrode provided on the insulating layer. (2) The base substance η1 forming the light-emitting layer is sulfurized lead. , :l-ref 1 ~ [1 Lumine Hins Kenko.