JPS617601A - Infrared light and humidity composite sensing material - 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 [Technical Field of the Invention] The present invention relates to an infrared light/humidity composite sensing material that detects an infrared source and atmospheric humidity by changes in electrical resistance.

[Prior art]

Conventionally, among the photoconductive materials used in photoconductive cells,
For infrared light, PbE, Pb2O, nsb,
Crystals, sintered bodies, thin films, and the like have been known for a long time, and are still used in many fields today.

In addition, a wide variety of electrical resistance-variable humidity-sensitive materials have been proposed for use in humidity sensors;
Ceramic materials such as JP-A No. 57-145301 and JP-A-55-10502, % Komei 55
It can be said that both polymer electrolyte materials such as those disclosed in Japanese Patent No. 42700 and Japanese Patent No. 57-20570 are mainstream.

In this way, although there are many infrared light-sensing materials and moisture-sensitive materials, this is the only material that can detect both infrared light and humidity by changing the total electrical resistance with the same material. A power that never existed before). There are a few products proposed by this inventor in Japanese Utility Model Publication No. 58-41474 and Japanese Unexamined Patent Application Publication No. 55-51346 that are considered to be somewhat similar, but these have a ζ shape on the photoconductive cell. In addition to the light absorption edge of the material, the photocurrent generated in response to short-wavelength irradiation also has humidity dependence.A photoconductive humidity detection device using gold can be used to detect changes in the resistance value of the material itself depending on the humidity. It was not possible to measure humidity by using this method, and it was different from the gist of the present invention.

Furthermore, when conventional infrared light sensing materials and conventional moisture-sensitive materials (organic electrolytes, ceramics, inorganic salts, etc.) are combined (compounded), only one type of detection or humidity detection can be performed. It is certain that this will not be possible.

[Summary of the invention]

This invention was developed in order to completely eliminate the drawbacks of the conventional PI) chalcogen compound.

By using a sintering residue of a composition containing at least one of InSb, Si and Ge as an infrared source detection material, and an organosilicon compound polymer, it is possible to The purpose of the present invention is to provide a composite infrared light/humidity detection material that can detect external light and atmospheric humidity with high sensitivity.

[Embodiments of the invention]

Examples of the organosilicon compound polymer according to the present invention include 1, for example, an initial polymer of organopolysiloxane. toluene,
Commercially available silicone varnish dissolved in a solvent such as xylene is easy to use, but it is not always necessary to use an initial polymer.

In the Σ infrared light detecting material according to the present invention, the chalcogen compounds of Pb, InSb, Si and Ge, can be used alone or in combination in combination to provide sufficient practical use. A humidity composite sensing material can be obtained.

The present invention will be explained in detail by showing Examples below, but the present invention is not limited thereto.

Embodiment 1 Fig. 1 is a perspective view of an infrared light/humidity composite sensing element using an infrared light/humidity composite sensing material according to an embodiment of the present invention. , (2) is an infrared light/humidity combined detection film, (3) is an electrode, and (4) is a lead wire.

That is, a varnish containing a methyl silicone initial polymer dissolved in xylene as an organosilicon compound polymer, and P
bs powder and 'll-2:8. Crosstalk was carried out by a mill at a weight ratio of . Paste-like crosstalk kA120s insulation board (1
) on top with a thickness of about 30 μm and a large size of 5 x 1 f
Shaped into an awn. After this thing is completely dry.

The slag was calcined in air at 130°C for 3.5 hours. K A is vapor-deposited on both ends of the fired film to form electrodes (2).
G Attach to the cu lead wire (4)' with paste.

An infrared light/humidity composite sensing element using an infrared light/humidity composite sensing material according to an embodiment of the present invention as shown in FIG. 1 was obtained. In addition, in this state, the infrared light/humidity combined detection film (
2) has a size of +3 Mm x 10 gyB and a thickness of about 1
It was 0 μm.

For a rough comparison, we prepared all conventional photoconductive cell PBS vapor-deposited films with electrodes attached.

When we measured all the spectral sensitivity characteristics and humidity sensitivity characteristics (0 relative humidity - electrical resistance value) in infrared light using a pixel element, we found that the second
The results shown in Figures 1 and 3 were obtained.

In Fig. 2, curve 1 (A) is the spectroscopic spectrum of an element using a conventional PbS vapor-deposited film, and curve (B) is the spectral spectrum of an element using a film made of the infrared light/humidity composite sensing material υ of an embodiment of the present invention. This is a sensitivity characteristic curve.

Note that the vertical axis represents the relative sensitivity when the peak value of the original current is set to 100. In this figure, the conventional Pbs vapor-deposited film has a sharper peak and slightly better sensitivity, but the sensitivity of one embodiment of the present invention is also relatively good. It is considered that there is no problem in practical use.

In Figure 3, ゛(,・t9M) (C) is a conventional Pbs vapor deposited film.

(It is clear from the figure that DJ is the moisture sensitivity characteristic curve of each film made of the sensing material of the present invention.) As shown in the figure, the electrical resistance value (Q) of the conventional one changes even when the relative humidity changes. Since Vζ hardly changes (sensitivity is low), it cannot be used practically as a moisture-sensitive material at all. On the other hand, the sensitivity of one example of this yoke was very good, and the electrical resistance value changed by almost four orders of magnitude when the relative humidity ranged from 10% to 95%.

The reason why the product according to the embodiment of the present invention has good moisture sensitivity characteristics is that the organic compound polymer is thermally decomposed during baking and the film becomes porous, and that the film is thermally decomposed.
Example 2: As the organosilicon compound polymer, Fes prepared by dissolving the initial polymer of methylphenyl silicone in xylene was used, and this, Pbse powder and 'i, -3: The mixture was kneaded in a mill at a weight ratio of T. Next, the entire device as shown in FIG. 1 was manufactured in the same manner as in Example 1. Tatami and firing in air and N2
Two types of devices using materials of an embodiment of the present invention were prepared by waiting at 950° C. for 3 hours in a gas stream. About pixel elements.

When the spectral sensitivity characteristics and moisture sensitivity characteristics were all measured in the same manner as in Example 1, the results shown in FIGS. 4 and 5 were obtained. Fourth
In the figure, one curve (El is the one using the film fired in air, and (P) is the spectral sensitivity characteristic curve for the one using the film fired in N2 gas.

As can be seen from this figure, the absorption edge peak (approximately 5 μm) is slightly sharper for those fired in a N2 gas stream.
It was also highly sensitive.

In FIG. 5 VC'j6, curve 1 (G) is the moisture sensitivity characteristic curve for the product fired in air, and curve (H) is the humidity sensitivity characteristic curve for the product fired in N2 gas. Like this 1 power 1 = clear power).

It can be said that when fired in N2 gas, a product with a lower resistance value and easier to use can be manufactured.

The above experiment by the same university was carried out under the atmospheric conditions for firing in air.
Although firing was carried out at different temperatures (e.g. temperature, temperature, etc.), it was found that a better infrared light/humidity composite sensing material could be produced by firing in a burnt N2 atmosphere.

Furthermore, when other inert gas such as pKAr was used instead of N2 gas, results similar to those described above were obtained.

The reason why firing in an inert gas produces products with high photosensitivity and low resistance in terms of force and moisture sensitivity is that the firing occurs without oxygen as an impurity being mixed in, and that Some baked products of organosilicon compound polymers5
This seems to be due to the fact that the conductivity is higher than that in the case where it becomes iCi and becomes 5io2 when fired in air.

Example 3 After applying the kneaded product used in Example 1 to a fully insulated substrate.

Figure 1 shows how the infrared light sensitivity of a combined infrared light and humidity sensing element similar to that shown in Figure 1 differs depending on the firing temperature in air. did. The results are shown in FIG.

In FIG. 6, song #(1) shows a curve of changes in photosensitivity depending on the firing temperature of an element using the material of one embodiment of the present invention. However, in FIG. 6, the ratio of the charging current to the dark current at the optical absorption edge wavelength (approximately 3.3 μm) is shown as the photosensitivity.

As can be seen from this figure, in the element using the material sound of one embodiment of the present invention, an element with excellent light sensitivity can be obtained by firing at 600° C. or higher. The reason for this is thought to be that the thermal decomposition of the organosilicon compound polymer is almost completed at 60° C. or higher and that sintering progresses. A similar tendency was also observed when firing in an inert gas.

Example 4 The kneaded product used in Example 2 and 3.5% by weight of 2C! 05 k added in total air at 1050°C for 3 hours, and used on the infrared light/humidity composite sensing material of other examples of this invention and other examples of awns of this invention. An infrared light/humidity composite sensing element similar to that shown in FIG. 1 was obtained. All spectral sensitivity and moisture sensitivity characteristics of the pixel elements were measured in exactly the same manner as before. As a result, both 9 showed almost the same characteristic curve in terms of spectral sensitivity characteristics.

Regarding the moisture sensitivity characteristics, different characteristic curves were shown as shown in FIG. In FIG. 7, curve 1 (J) is a characteristic curve without x2co5 added (K) and line 1 with x2co3'2 added. As is clear from this figure, K2C
! When all 05 is added, the resistance value decreases by about one order of magnitude on average, making it easier to use. Furthermore, the same effect as above is also seen when using other Pb chalcogen compounds, at least one of InSb, Eli, and Ge 2 O, and when all other alkali metal compounds are added.

From the above, it is preferable that the composition according to the present invention contains an alkali metal compound, since the resistance value of the infrared light/humidity composite sensing material of the present invention decreases in terms of humidity sensitivity.

〔Effect of the invention〕

As described above, the present invention provides a method for producing a composition containing a chalcogen compound of Pb, at least one of the infrared light sensing materials of InSb, Si and Ge, and an organosilicon compound polymer. By using the same material, it is possible to obtain an infrared light/humidity composite sensing material that can detect the infrared source and the humidity of the atmosphere with high sensitivity.

[Brief explanation of drawings]

FIG. 1 is a perspective view of an infrared light/humidity composite sensing element using an infrared light/humidity composite sensing material sound according to an embodiment of the present invention, and FIGS. 2 and 3 are respective examples of the present invention. A spectral sensitivity characteristic diagram and a humidity sensitivity characteristic diagram comparing an infrared light/humidity composite sensing element using the infrared light/humidity composite sensing material of 2008 and an infrared light sensing element using a conventional infrared light sensing material, Figures 4 and 5 are. Fig. 6 shows a spectral sensitivity characteristic diagram and a moisture sensitivity characteristic diagram for comparing the firing atmosphere of an infrared light/humidity composite sensing element using infrared light/humidity composite sensing material sound of other embodiments of the present invention, respectively. A diagram of changes in light sensitivity due to baking and storage of an infrared light/humidity composite sensing element using an infrared light/humidity composite sensing material according to an embodiment of the present invention. In Fig. 1, which is a moisture sensitivity characteristic diagram comparing the effect of alkali metal compound inclusion in infrared light/humidity combined sensing elements using sensing materials, (1) is an insulating substrate, (2) is an infrared light humidity combined sensing element. Film, (3) electrode, (4) lead wire, (A),
(0) are the spectral sensitivity characteristics and moisture sensitivity characteristics of the conventional example, respectively, (
B)(]!i), (F) are the spectral sensitivity characteristics of the infrared light/humidity composite sensing element using the infrared light/humidity composite sensing material of the embodiment of this invention, (D), (G), (H), (
J>, (K) is the humidity sensitivity characteristic of the infrared source instantaneous humidity composite sensing element using the infrared light/humidity composite sensing material of the example of this invention, (J) is the infrared light of the example of this invention・This is a photosensitivity curve of an infrared light/humidity composite sensing element using a humidity composite sensing material.

Claims (1)

[Claims] An infrared light/humidity composite sensing material comprising a firing residue of a composition containing a chalcogen compound of Pb, at least one of the infrared sensing materials of InSb, Si, and Ge, and an organosilicon compound polymer.