JPH0660002B2 - How to store high-purity germanes - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method of safely storing flammable (spontaneous) and highly toxic germanes (germanium hydrides) in high purity.

[Conventional technology]

Demand for germanes has rapidly increased in recent years as a material for controlling the energy gap of amorphous silicon photoconductors and amorphous silicon solar cells, that is, the band gap to a smaller value. However, the physical properties of germanes have not been fully elucidated since they are still new to industrial use, and there are almost no reports on compounds that serve as long-term storage stability or decomposition catalysts.

However, regarding the conventional findings, it has been reported that germanes are very self-touching and that they decompose rapidly once they are decomposed to form a metal film.
In the latter half of nine years, there was even an accident in which a cylinder filled with monogermane exploded. For this reason,
Above all, the establishment of a method for safely storing germanes is strongly desired.

DISCLOSURE OF THE INVENTION At present, as a method for producing germanes, for example, a method of reacting an alloy of magnesium and germanium with an acid, a method of reducing halogermane such as germanium tetrachloride with various reducing agents, and the like are known as main methods. Has been.

As a result of diligent studies on the stability of the product germanes produced by such a method, the present inventors have found that the halogens contained in the product have an extremely large effect on the storage stability of the germanes. The present invention has been completed.

That is, according to the present invention, the content of the halogen element is 5 wt.p.
High-purity germanes excellent in stability, which are reduced to pm or less, preferably 3 wt.ppm or less.

The present invention will be described in detail below.

The germanes in the present invention mean germanium hydride represented by the general formula Ge _n H _{2n + 2} (where n is an integer of 1, 2, 3, ..., And the like), and of course, a mixture thereof is also included. .

The halogen element in the present invention means fluorine, chlorine, bromine, and is collected by passing germanes through an impinger or bubbler containing an alkaline aqueous solution such as a caustic soda aqueous solution, and then by a reverse polarographic method or a colorimetric method. Analysis quantified. In calculating the content of halogen elements in germanes, calculate the halogen content weight from the concentration measured by the reverse polarographic method or colorimetric method, and calculate this weight as the weight of germanes passed through an impinger or bubbler. Just remove it.

In the present invention, the means for removing and refining the halogen element from germanes is not limited, but the refining and removal can be performed by means usually used for removing the halogen element from the halogen element-containing gas. Above all,
Means such as adsorption removal by activated carbon and bubbling into a weak alkaline aqueous solution are preferably adopted.

The present invention will be described below with reference to examples.

Comparative Example 1 When a commercially available monogermane gas was obtained and analyzed, the purity was 99.9%, but the chlorine content was 10 wt.ppm.

This monogermane gas is put into an autoclave with an internal volume of 200 ml and the inside is clean (body and valve are made of SUS304).
0 ml was added. After filling with monogermane gas, a part of the internal gas was extracted and subjected to a purity analysis by gas chromatography to find that the purity was 99.9%. Then, the autoclave was heated to 100 ° C. in an oil bath and left for 20 hours. Analysis of germane in the autoclave gives a purity of 99.3
%, And it was found that the purity was considerably lowered.

Example 1 The monogermane gas used in Comparative Example 1 was purified by passing through an activated carbon adsorption tower. The purity of the purified monogermane gas was 99.9%, which was unchanged, but the chlorine content was 4 wt.p.
It was dropping to pm.

This monogermane gas is put into an autoclave with an internal volume of 200 ml and the inside is clean (body and valve are made of SUS304).
0 ml was added. After filling with monogermane gas, a part of the internal gas was extracted and subjected to a purity analysis by gas chromatography to find that the purity was 99.9%. Then, the autoclave was heated to 100 ° C. in an oil bath and left for 20 hours. Analysis of germane in the autoclave gives a purity of 99.8
%, And almost no decrease in purity was observed.

Example 2 The monogermane gas used in Example 1 was further purified by passing through an activated carbon adsorption tower. The purity of the monogermane gas after purification was unchanged at 99.9%, but the chlorine content was
It had dropped to 2 wt.ppm.

This monogermane gas is put into an autoclave with an internal volume of 200 ml and the inside is clean (body and valve are made of SUS304).
0 ml was added. After filling with monogermane gas, a part of the internal gas was extracted and subjected to a purity analysis by gas chromatography to find that the purity was 99.9%. Then, the autoclave was heated to 100 ° C. in an oil bath and left for 20 hours. Analysis of germane in the autoclave gives a purity of 99.9
%, And no decrease in purity was observed.

Comparative Example 2 Bromoic acid was added to the adsorption-purified monogermane gas used in Example 2 to adjust the bromine concentration in the monogermane to 12 wt.ppm.

This monogermane gas is put into an autoclave with an internal volume of 200 ml and the inside is clean (body and valve are made of SUS304).
0 ml was added. After filling with monogermane gas, a part of the internal gas was extracted and subjected to a purity analysis by gas chromatography to find that the purity was 99.9%. Then, the autoclave was heated to 100 ° C. in an oil bath and left for 20 hours. Analysis of germane in the autoclave gives a purity of 99.4
%, And it was found that the purity was considerably lowered.

Claims (1)

[Claims] 1. A halogen which is contained as an impurity in germane in the storage of germane represented by the general formula Ge _n H _{2n + 2} (where n is an integer such as 1, 2, 3, ...). Element content is 5wt
A method for preserving high-purity germanes, which is characterized by storing as ppm or less.