JPS60133455A - Manufacture of photoconductive cadmium sulfoselenide - Google Patents

Abstract

PURPOSE:To enable sensitization in a longer wavelength region by incorporating Cu and a large amt. of In in Cd sulfoselenide. CONSTITUTION:A flux mixture of 2.0-4.0mol CdCl2 and 100mol NaCl is added to a mixture of CdS and CdSe in a flux mixture to the latter mixture weight ratio of (30-100):100, burned at 550-590 deg.C, and again burned to obtain Cd sulfoselenide. Cu and In are added to it in an amt. of 10X10<-4>-30X10<-4>mol of In per mol of said Cd sulfoselenide, dependent on the balance with Cu content, and a necessary amt. of Cu to be added is 6X10<-4>-15X10<-4>, its optimum amt. being dependent on the content of In.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing photoconductive cadmium selenide sulfide suitable for electrophotography.

In general, a cadmium selenide sulfide mixed crystal can be used to produce a photoconductor with higher sensitivity than a photoconductor made of cadmium nitride alone. Therefore, if a highly sensitive light guide system is required, it is advantageous to select cadmium selenide.

(pR, cadmium selenide N is a valence; a mixture of cadmium oxide particles and selenium electrons or cadmium selenide particles,
Created by high-temperature firing. However, in the case of cadmium selenide sulfide produced by the conventional method, the shape of the starting material remains unchanged. In other words, it consists of secondary particles, which are strong aggregates formed by particles aggregating with each other, and these secondary particles aggregate three-dimensionally to form a nodule, or aggregate two-dimensionally. There are various types of flat plate shapes, and some of them are large, ranging from 10-odd microns to several tens of microns in size.

A photoreceptor made using cadmium selenide sulfate containing a large number of such coarse particles has a poor surface condition b0, and as a result, the resulting image is rough and has insufficient resolution. Furthermore, in the case of a photoconductor further provided with an insulating layer, the insulating layer may seep into the cadmium selenide sulfide layer, making it difficult to obtain a good photoconductor.

In addition, cadmium sulfate selenide produced by the conventional method through a sintering process has a large number of defects near the CdS L surface during precipitation.

These surface defects cannot be removed by the sintering process, so they become trap levels for photocarriers 9 and increase the photomemory of cadmium selenide sulfide. In other words, photoreceptors made using such cadmium selenide sulfur have a slow photoresponse speed, and the electrostatic contrast between bright and dark areas in first-time copies is insufficient1. However, as demand for copying methods with intelligent functions emerges, the sensitivity of cadmium selenide sulfide particles itself becomes insufficient. Especially when using a laser light source/+: When the attraction to copying machines begins to appear,
Photoreceptor particles are required to have high sensitivity at long wavelengths, particularly at 750 to 800 nm or more due to laser light. The particles according to the invention have no sensitivity on the long wavelength side, and are not sufficiently sensitive to light in the infrared region, so they cannot be used for the above purpose.

An object of the present invention is to provide a method for producing photoconductive cadmium selenide octasulfide which requires less optical memory, has excellent image quality, and has high sensitivity.

The present invention uses a mixed flux of cadmium chloride and sodium chloride containing 2.0 to 4.0 mol% of cadmium chloride.
3 for mixtures of cadmium oxide and cadmium selenide
A phototetraelectric cadmium selenide sulfide characterized by adding 0 to 100 ffi amount%, firing at 550 to 590°C, and further firing to dissolve copper and indium into the cadmium selenide sulfide. By incorporating copper and indium into cadmium selenide sulfate using the manufacturing method described above, sensitization in the long wavelength range was made possible by incorporating a large amount of indium, especially indium. Since the shape of the MafC cadmium selenide sulfate particles is simple and each particle has a flat surface, it can be a photoconductive particle with little optical memory and good image quality.

/- Indium is necessary to extend sensitivity to the long wavelength side, but the amount of indium is determined by the balance with copper. In the present invention, the minimum amount in order to have sensitivity on the long wavelength side is 10 to 1 mole of cadmium selenide sulfide produced.
X 10-' mol is required, and the maximum amount is fl-30X 10-4 mol, which satisfies the dark resistance for electrophotography.

The simplest method for cooling indium is to add it to the reaction solution and coprecipitate it. Copper is doped as an acceptor to maintain balance with the donor, but copper can be added in advance to a cadmium salt aqueous solution and co-precipitated to be included in cadmium sulfide, or it can be added before firing or re-calcining. It can also be incorporated into cadmium polysulfide by first mixing it with a mixture of cadmium sulfide and cadmium selenide and then firing or re-firing. Copper chloride is a copper compound.

Sulfides, sulfates, etc. are used, especially copper sulfide.

Copper sulfate is preferred 7. A method of adding a copper compound before forming Class 1 or before recalcination is to add the copper compound to a solid state of 1'=1. It may be added and mixed,
; In the case of iu+ compound or water-soluble 1'iu, good results can be obtained by the wet method in which it is made into an aqueous solution, added to a mixture of cadmium sulfide and cadmium selenide, and then the water is evaporated, but it is difficult to achieve uniform mixing. The wet method is better.

The optimum amount of addition differs depending on the amount of indium, and particularly in the case of the present invention, the allowable range of addition of copper relative to the amount of C and indium is narrow. 6 per mole of cadmium selenide
X 10-4 to 1'5 X 10-' moles are necessary.

The oxidation property of cadmium selenide sulfide mixed crystal changes depending on the sulfur and selenium values. The range where selenium is contained in an amount of 5 to 30 mol % based on the mixed crystal is preferable to bring about effective effects on the target properties such as sensitizing effect and reduction of optical memory. When it is less than 59, the effect of adding selenium is obtained. When M<30% or more, the movement of the generated carriers becomes poor.

The fluxing agents used in the present invention include CdCtz and N, which are commonly used when diffusing active agents into cadmium sulfide.
aC6 is mixed and used as a fluxing agent.

The mixing ratio of CdCLz to NaC4 is 2.0 to 4.
．． 0 mol% is preferred. 12.0 molar volume or less. f
,,The cadmium sulfide particles produced in '11 are! (This is not the case with cadmium sulfide, which has a small, uniform concave shape, the object of the present invention, and has a uniform particle size.)

If the concentration exceeds 4.0 mol% in 1, the electrophotographic properties will gradually deteriorate (3, especially the sensitivity is remarkable, and the photoreceptor produced by baking with the agent outside the above range will be ,
@ri N is used for copying machines.

In the present invention, the amount of the mixed flux added to the mixture of cadmium sulfide and cadmium selenide is 30 to 100
You must choose from a range of weighted areas.

When the amount added is small, #melting of the mixture of cadmium sulfide and cadmium selenide does not occur completely, probably because the amount of CdC4z in the mixed flux is small for the mixture of cadmium sulfide and cadmium selenide. , since the powder shape before firing remains and three-dimensional giant particles are present, the potential retention properties are not sufficient, and the image m1 also lacks resolution.

On the other hand, as the amount added increases, the cadmium selenide particles tend to gradually become larger. As the particles get larger, the resolution becomes progressively worse. On the other hand, as the Usuri lJ area increases, the sound collected by 1 Crucible Todoroki decreases. Furthermore,
As the amount of flux increases, the cost of flux for crucible drawing increases.

Obey, t! *+J Increased haze increases the cost of cadmium sulfate selenide produced. Also, in terms of security, the increase in the total number of CdCs 62 leads to disadvantages. Considering the characteristics and cost, the flux cap is made of a mixture of cadmium sulfide and cadmium selenide.
It must be less than 9 times.

In the present invention, the firing after mixing the flux must be carried out at a temperature 1000C or more higher than the melting point of the mixed flux, in the range of 550 to 590'C, since NaCt is present in excess. If firing is performed at 590℃ or higher,
The larger the diameter of the cadmium selenide sulfide particles produced, the worse the resolution.

In the present invention, the powder after firing is thoroughly washed with water and dried on the tjIr plate, but the powder obtained in this way is
Due to the large number of surface defects, the electrophotographic properties are not always satisfactory.

Therefore, in order to improve crystallinity and compensate for surface defects, the above-mentioned powder must be subjected to circular sintering once more.

The re-firing temperature is preferably in the range of 400 to 500'C.

The cadmium sulfur selenide powder produced according to the present invention is
It has high crystallinity, and when observed using a scanning electron microscope, the particles are single particles that do not aggregate with each other, and the shape is uniform, the particle size is small, and the surface is smooth. Since the coated surface of the layer was dense and smooth, an image of very high quality was obtained.

Regarding sensitivity, long wavelengths, especially 800 to +35
It was found that it was elongated at 0 nm i.

For Example 1, 10×10−′ and 20×
Cadmium sulfide containing 1 Cr' mole is prepared. Meanwhile, the same month creates cadmium selenide containing copper and indium, respectively. 500 g of the cadmium sulfide and 73.6 g of cadmium selenide were dispersed in pure water and stirred until uniformly mixed. This mixture was heated at 200'C for 1
After drying overnight, 225 g of sodium chloride and 25 g of cadmium chloride were added to 500 g of the mixture, and after thorough mixing, the mixture was charged into a quartz crucible and heated at 58oC to 60g.
Baking was performed for a minute. 70' after thoroughly cleaning the Saka-fired products.
It was dried at C overnight.

The hexagonal degree of @1 cadmium selenide produced in this way is 00%, and according to an electron micrograph at 10,000 times magnification,
It was observed that the particle surface was very smooth and had an orthogonal crystal shape, and each particle was a single particle with an average particle size of lμ.

Next, the cadmium selenide sulfate obtained in this way was added to 4
JJ re-fired for 1 hour at 50°C. After re-firing
Eyk 6 , ion 1M piece I fat IF l-su was removed and dried. After dispersing cadmium selenide sulfate in the vinyl chloride/vinyl acetate copolymer, it is coated on an aluminum substrate to a thickness of 40μ. 1) A 15μ thick polyester film is pasted on the dried photosensitive plate. When a photoreceptor with a three-layer structure was obtained, the surface was extremely smooth. Further, when the sensitivity was measured at 8OOnm, the half-reduction exposure polarization was 1.8μ. The photoreceptor obtained by this method had sufficient contrast, and images of extremely good quality and resolution were obtained7. Comparative Example 1 Cadmium sulfide and cadmium selenide powder containing 10 x 10-4 mol% of Cu only A single cadmium selenide body was prepared in the same manner as in Example 1, and a photoreceptor was prepared in the same manner.

When the sensitivity of this photoreceptor was measured, the sensitivity at 800 nm was 3.5 μm, and compared to Example 1, the contrast was lower and the image quality was also inferior.

Example 2 Copper, indium t (8 x 10"-', 15
Create cadmium sulfide containing 10"-' moles. Create cadmium selenide containing unidirectional amounts of copper and indium. 500 g of cadmium sulfide and 73.6 g of cadmium selenide are dispersed and mixed uniformly in pure water. After drying this mixture at 200°C overnight, 375g of sodium chloride and 25g of cadmium chloride were added to the mixture and mixed thoroughly.The mixture was then filled into a quartz crucible and heated at 590°C for 60°C. After that, it was washed in the same manner as in Example 1 and re-fired to obtain photoconductive cadmium selenide sulfate.

A photoreceptor was prepared in the same manner as in Example 1 using this cadmium selenide sulfide. However, good results similar to those of Example 1 were obtained.

In addition, the sensitivity at 800nm was measured and was 1.7μ%rn.
It was 2.

Claims (1)

[Claims] (1) Add a mixed flux of cadmium chloride and sodium chloride containing 2.0 to 4.0 mol% of Domiwam chloride to a mixture of cadmium Tsukuda and cadmium selenide at a concentration of 30 to 10% by mole.
1. A method for producing photoconductive cadmium selenide sulfide, which comprises adding 0% by weight of cadmium sulfide, firing at 550 to 590'C, and further firing to add copper and indium to cadmium sulfide selenide.