JPH0676280B2 - Method for producing organic single crystal with controlled growth direction - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing an organic single crystal of good quality and controlled in growth direction, for example, in the fields of optics, nonlinear optics, acoustooptics, information processing, and communication. It is preferably used. [Prior Art] In recent years, in the fields of optics, nonlinear optics, acoustooptics, information processing, and communication, there has been an increasing demand for using an anisotropic organic single crystal. In such a case, it is very convenient that a specific crystal axis exists in a specific orientation of a crystal having a specific shape according to each purpose. Further, it is more convenient if the location of crystal growth can be designated.

In response to such demands, conventional methods for producing single crystals of organic compounds are roughly classified into (a) vapor phase method (sublimation method, etc.) (a) melting method (Bridgeman method, etc.) (c) solution method. However, none of them is satisfactory as a manufacturing method capable of intentionally controlling the growth location and the growth direction of an organic single crystal, and the growth of a single crystal that can best meet the purpose is to grow. The only method is to use a single crystal of the organic compound as a seed crystal.

However, even with this method, it was practically difficult to obtain a crystal having a desired growth surface and arrange it at a desired growth site. Even if the above was possible, the dissolution and melting of seed crystals was a factor in setting very precise and limited crystal growth conditions.

On the other hand, for inorganic compounds, especially for semiconductors, homo-epitaxial growth and hetero-epitaxial growth, that is, a technique of growing a single crystal on a heterogeneous crystal is widely known.

However, even if various substrate crystals used for hetero-epitaxial growth of semiconductors, such as SiGaAs, are used as they are for the production of single crystals of organic compounds, the lattice constants are too different, that is, the lattice mismatch (misfit factor) occurs. It was too large for hetero-epitaxial growth.

[Problems to be Solved by the Invention] In the present invention, there is no limitation due to the melting and melting of seed crystals in the above-mentioned conventional method, and the growth such that the growth place and the growth orientation of the organic single crystal can be controlled easily and intentionally. It is an object of the present invention to provide a method for producing an orientation-controlled organic single crystal.

[Means for Solving the Problems] In order to achieve the above objects, the present invention has the following configurations.

“In a method for producing an organic compound single crystal from a gas phase, a solution phase, or a melt phase, a polydiacetylene derivative single crystal is allowed to coexist, and the polydiacetylene derivative single crystal has a lattice constant on the crystal face of the polydiacetylene derivative single crystal. A method for producing an organic single crystal having a controlled growth direction, which comprises a step of selectively growing a growth surface of an organic compound single crystal. ”The inventors of the present invention use a gas phase, a solution phase, or a melt phase. In the method for producing a single crystal of an organic compound, non-sublimability, non-solubility,
When a non-melting polydiacetylene derivative single crystal is allowed to coexist, a growth surface of an organic compound single crystal that matches the lattice constant of the crystal surface of the polydiacetylene derivative single crystal can be selectively grown. The inventors have found the present invention and have reached the present invention.

In the present invention, the organic compound for which a single crystal is useful may be any organic compound useful in optics, nonlinear optics, acoustooptics, etc. 4-nitroaniline (MN
A), N- (4-nitrophenyl) -L-prolinol (NPP), N- [2- (5-nitropyridyl)]-L-
Prolinol (PNP), 2-acetylamino-4-nitro-N, N-dimethylaniline (DAN), 2- (α-methylbenzylamino) -5-nitropyridine (MBANP), 4
-Aminobenzophenone (ABP), 4-methyl-7-diethylaminocoumarin, 4'-dimethylamino-N-methyl-4-stilbazolium-methosulfate (DMS
M) 4'-nitrobenzylidene-4-methylaniline, 4'-nitrobenzylidene-3-acetamino-4
-Methoxyaniline (MNBA), 4-methoxy-3-methyl-4'-nitrostilbene (MMNS), 4-bromo-
4'-Nitrostilbene and other secondary nonlinear optical effects, and perylene / tetracyanoethylene (TC
NE) complex, perylene / 7,7,8,8-tetracyanoquinodimethane (TCNQ) complex, and others that exhibit a third-order nonlinear optical effect. Another example of an organic compound that exhibits a second-order nonlinear optical effect is “Nonlinear Optical Properties of Organi”
c Molecules and Crystals ″ ed.by DSChemla and JZ
yss, Academic Press, 1987, vol.1.Chapter II-3, pp227〜
Detailed in 296.

Since the polydiacetylene derivative single crystal has various lattice constants, it has a feature that it is possible to easily select a crystal suitable for orientation-controlled growth of a target organic compound single crystal. Furthermore, since it is non-sublimable, non-soluble, and non-meltable, there are almost no restrictions when it is used in the intended range. The present invention has been achieved by utilizing the properties of the single crystal of the polydiacetylene derivative. Furthermore, most of the polydiacetylene derivative single crystals have a one-dimensional or two-dimensional structure, which is characterized by the fact that a smooth and fresh crystal plane can be easily obtained by cleavage. As the polydiacetylene derivative single crystal, one having at least one property of non-sublimation property, non-solubility property and non-melting property under the manufacturing condition is preferably used when carrying out the manufacturing method of the invention. Many polydiacetylene derivative single crystals are known (for example, Hans
-Joachim Cantow Ed,. ″ Polydiacetylenes ″ Springer-
Verlag, 1984), for example, poly [2,4-hexadiyne-1,
6-diol bis (p-toluene sulfonate)] (PT
S), poly (hexa-2,4-diyne-1,6-diylbisphenylcarbamate) (HDU), poly (dodeca-5,7-
Diyne-1,12-diyl bisphenyl carbamate)
(TCDU), poly [1,6-di (carbazolyl) -2,4-hexadiyne] (DCH) and the like. The lattice constants are described on pages 124-125 of the aforementioned references.

For the purpose of obtaining a bulk single crystal of an organic compound, a polydiacetylene derivative single crystal in a Bridgman method or a solution crystallization method, which is a kind of melting method, may be used as a seed crystal, or may be a thin film single crystal. Alternatively, it may be used as a substrate crystal or a seed crystal.

As described above, effective crystallographic orientation control of an organic single crystal can be achieved by selecting an appropriate crystal plane of the polydiacetylene derivative single crystal so as to satisfy the lattice matching condition with respect to the target crystal growth surface of the organic compound. Can be achieved.

[Examples] Poly [2,4-hexadiyne-1,6-diolbis (p-toluenesulfonate)] (PTS) single crystal (001)
The examples of MNBA single crystal growth on the cleavage plane will be described, but the present invention is not limited to these examples.

Example 1 5.0 g of fine crystals of 4'-nitrobenzylidene-3-acetamino-4-methoxyaniline (MNBA), which is an organic material having a large second-order nonlinear optical effect, was dissolved in 100 ml of dimethylformamide to prepare a simple solution of PTS. Crystal (monoclinic P21 / c, lattice constant a = 14.993Å, b = 4.910Å, c = 14.936Å, β
(= 118.14 °), it was spread on the (001) cleaved surface, sandwiched with a cover glass from above, and crystallized by slow evaporation at room temperature. Although it was a very rapid crystal growth condition that crystals grew after a dozen hours, uniform and transparent yellow crystals were obtained on PTS. This MNBA crystal was peeled from the PTS single crystal substrate, and the cross
It was found to be a single crystal by observing under Nicol. As a result of repeating similar crystal growth, it was confirmed that a single crystal was always obtained. Next, when these single crystals were examined by X-ray diffraction, it was always found that (001)
It was found that the surface grows on the PTS (001) cleaved surface.

When the misfit factor of the (001) plane and the PTS (001) plane of the MNBA single crystal was calculated, it was aa '(a is PTS
, A'is -11.8% in the MNBA crystal axis orientation) b
It was confirmed that the value was −9.3% in the −b ′ direction, both of which were smaller than the limit value of 15% which is the limit value for hetero-epitaxial growth.

Example 2 A few tens of mg of MNBA was placed on a cover glass and from above
Put (001) cleavage planes of PTS single crystal on top of each other
MNBA with a melting point near 189 ° C when heated to 200 ° C on a plate
Was melted and gradually cooled at a temperature lowering rate of less than 0.1 ° C./hour. After cooling to room temperature, transparent yellow crystals were obtained on PTS. In the same manner as in Example 1, the MNBA crystal was separated from the substrate PTS single crystal,
By observing under crossed Nicols of a polarizing microscope,
It was found to be a single crystal. As a result of repeating similar crystal growth, it was confirmed that a single crystal was always obtained by the above method. However, when the (001) cleaved surface of the PTS single crystal was set to the hot plate side and cooled from the cover glass side to cause crystallization, a single crystal could not be obtained in most cases.

Next, when the previously obtained single crystal was examined by X-ray diffraction, it was found that the (001) plane of the MNBA single crystal was always grown on the PTS (001) cleavage plane.

Therefore, in the case of the melting method, it was shown that it is important to set the temperature conditions so that the crystallization of MNBA occurs from the (001) cleavage plane side of the PTS single crystal.

Example 3 tens of mg of MNBA was melted between two slide glasses, and the melt was made of PTS single crystal (001) at one end of the slide glasses.
Applying a brass heat sink from the back of the cleaved plate-shaped PTS single crystal so that it contacts the cleaved surface, crystallization of MNBA occurs from the (001) cleaved surface side of the PTS single crystal under temperature conditions. Was set. After gradually cooling to room temperature, transparent yellow crystals were obtained between the slide and glass. As in Example 1, the MNBA crystal was observed under a crossed Nicols with a polarizing microscope, and it was found to be a single crystal.
As a result of repeating the crystal growth in the same manner, it was confirmed that a single crystal was always obtained by the above method. However, in this case, it was found by X-ray diffraction that the wide surface of the MNBA single crystal grown between the slide and the glass was not the (001) surface but the (010) surface.

This example shows that a thin film single crystal having a specific growth orientation can be obtained with good reproducibility between glass substrates.

Example 4 Several g of MNBA was placed on a resistance heating boat of a vacuum vapor deposition machine, and a PTS single crystal having a (001) cleavage plane was attached to a substrate holder located about 35 cm above the resistance heating boat. About 10 ^-4 Torr
Deposition was performed at a slow deposition rate of about 5Å / sec. The vapor deposition was stopped when the deposited film thickness reached about 5000Å, and the PTS single crystal cleavage plane was observed. Innumerable microcrystals having a substantially uniform size (several μm to several tens μm) and shapes were formed with the orientations aligned in substantially the same direction, but a large thin film single crystal could not be obtained.

Next, the PTS single crystal as the substrate was heated to maintain the temperature at about 150 ° C., and MNBA was deposited under the same conditions as above. About 5000Å
The cleavage plane of PTS single crystal with MNBA deposited film thickness was observed. P
A yellow transparent film was formed almost uniformly on the cleavage plane of the TS single crystal. As in Example 1, this MNBA film was peeled from the substrate PTS single crystal and observed under a crossed Nicols using a polarizing microscope, and it was found to be a single crystal. As a result of repeating similar crystal growth, it was confirmed that a single crystal was always obtained by the above method.

Next, when the obtained single crystal was examined by X-ray diffraction,
It was found that the (001) plane of MNBA single crystal always grows on the PTS (001) cleavage plane.

Therefore, the MNBA single crystal can be grown on the (001) cleavage plane of the PTS single crystal by the vapor phase method, but it was shown that the temperature setting of the substrate PTS was important.

EFFECTS OF THE INVENTION The present invention uses a polydiacetylene derivative single crystal as a growth substrate crystal or a seed crystal so that the growth location and the growth orientation of an organic single crystal can be controlled easily and intentionally. A method for producing an organic single crystal can be provided.

Claims (2)

[Claims] 1. A method for producing an organic compound single crystal from a gas phase, a solution phase, or a melt phase, wherein a polydiacetylene derivative single crystal is allowed to coexist, and the crystal plane lattice of the polydiacetylene derivative single crystal is present. A method for producing an organic single crystal having a controlled growth direction, comprising the step of selectively growing a growth surface of an organic compound single crystal that matches a constant. 2. The method for producing an organic single crystal having a controlled growth direction according to claim 1, wherein the organic compound is a non-linear optical material.