JPS6073628A - Photoconductive member - Google Patents

Abstract

PURPOSE:To improve the electrostatic chargeability and retentivity and to prevent interlaminar stripping by successively forming blocking layers and a photoconductive layer contg. Si and a IIIA or VA group element in common as constituent elements on a support. CONSTITUTION:An electrically conductive support 1 is put in a vacuum reactor, and the reactor is evacuated to 10<-3>-10<-4>Torr with a mechanical booster pump. At this time, the support is kept at 100-400 deg.C. A gas contg. Si such as SiH4 or Si2H6 and a doping gas contg. a IIIA or VA group element are introduced into the reactor in a desired mixing ratio, and the exhaust speed of an exhaust system is regulated. High frequency power of 13.56MHz is then applied between electrodes in the reactor to form blocking layers 2, 3, a photoconductive layer 4 and a surface coating layer 5 on the support 1 in succession.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a leading material A that is sensitive to light (electromagnetic waves such as ultraviolet to visible and infrared bXWIA* gamma rays).

[Technical background of the invention and its problems]

Photoconductive materials constituting the photoconductive layer of solid-state imaging devices, electrophotographic photoreceptors, etc. have a high specific resistance in the dark (usually 101 mΩ or more) and are sensitive to light irradiation due to the purpose of use. It is necessary to have the property of reducing specific resistance.

Let's explain smoke removal using electronic photography as an example.

First, the surface of the photoreceptor is fully charged by corona discharge. Next, when the photoreceptor is irradiated with light, pairs of electrons and holes are created, and one of them neutralizes the charge on the surface. for example.

When positively charged, it is neutralized by electrons among the pairs generated by light irradiation, and a positively charged latent image is formed on the surface of the photoreceptor. Next, visualization is performed by attracting toner charged to the opposite polarity to the surface of the photoreceptor by Coulomb force. At this time, in order to avoid toner being attracted to the photoconductor due to the toner charge even if there is no charge, the potential of the developer is set high so that an electric field in the opposite direction to the electric field due to the charge is generated between the photoconductor and the developer. do. A so-called developing bias process is performed.

In the electrophotography described above, Fi and its photoreceptor are required to satisfy the following conditions. That is, firstly, the charge generated by corona discharge is retained until light irradiation, and secondly, the electron-hole pair generated by light irradiation does not recombine and one neutralizes the surface charge. Furthermore, it is required that the other side instantly reach the support of the photoreceptor.

By the way, amorphous chalcodanide-based materials have conventionally been used as photoconductive materials.

Amorphous chalcognide can be easily made into a large area.

It also has characteristics such as excellent photoconductivity. However, the absorption band of such amorphous chlorine is from the visible to near the ultraviolet range, making it difficult to use in practice.

Sensitivity to visible light is low, and rupture is low at 1w.
When applied to electrophotography, there were various problems such as short life.

For these reasons, the use of amorphous silicon (hereinafter referred to as a-84) as a photoconductive material has recently attracted attention. a-S has a wide absorption wavelength range,
It is maternally chromatic and highly sensitive. In addition, it has high hardness, and when applied to electrophotographic photoreceptors, it is expected to have a lifespan more than 10 times longer than conventional ones.

Furthermore, it is harmless to the human body, and has many advantages when compared to single crystal silicon, such as being inexpensive and easily obtainable over a large area. however.

A-81 has a low specific resistance in the dark (hereinafter referred to as dark resistance) and has a low specific resistance (hereinafter referred to as dark resistance).
In a device that forms an electrostatic latent image, such as an electrophotographic photoreceptor, it is impossible to retain a charge on one surface.

Therefore, in an example in which a-81 is applied to electrophotography, an a-81 layer with high resistivity or a p-type layer in which N, C, O, etc. are added between the photosensitive layer and the support is used.

Attempts have been made to provide an n-type a-81 layer to prevent carrier injection from the support. However, the latter a-8
When using layers, use a p-type a-81 layer that blocks electrons and allows holes to pass in the case of a positive charge, and use an n-type a-8 layer ft in the case of a negative charge. do. A photoreceptor having such a structure can have a high charging ability.

However, in the former structure, a with added N, C, and 0
If the -8i layer is made thicker, it also blocks the passage of carriers flowing from the photosensitive layer to the support, resulting in a problem of higher residual potential.

On the other hand, when the a-8i layer is made thinner, dielectric breakdown occurs due to development bias. In the latter structure, p-type, n-type a, -
Even if the 81 layer is made thicker, the former problem does not occur. However, the a-81 layer becomes pp type by adding the first group A element and becomes n type by adding the first group VA element, but the addition of these impurities causes strain in the layer. The Koushi 9a-8i layer was used as a blocking layer.

When a photoconductive layer is laminated on top of the photoconductive layer, the strain of each layer is different, resulting in inconveniences such as delamination between layers. A similar problem also occurs with regard to the surface coating layer laminated on the photoconductive layer.

Furthermore, a photoconductive member having a structure combining both of the above-mentioned 9a-8i layers has also been proposed (Japanese Patent Laid-Open No. 57-177156).
issue). That is, this photoconductive member is a p-type or an n-type photoconductive member on a support.
type a-81 layer and a-81 added with N, C, 0, etc.
The layers are laminated one after another, and a photosensitive layer is further laminated on top of the layers. However, in such a photoconductive member, N
, C, O, and the like will naturally increase the residual potential.On the other hand, if the a-8 layer is made thin so as not to increase the residual potential, dielectric breakdown or the like will occur.

[Purpose of the invention]

The present invention has been made in view of the above circumstances, and aims to provide a long-life photoconductive member that can improve chargeability and retention ability to the same level or even higher than conventional ones, and prevents peeling between S layers. be.

[Summary of the invention]

The present invention relates to a photoconductive member comprising a blocking layer and a photoconductive layer sequentially on a support.

All the layers of the blocking layer and the photoconductive layer commonly contain at least Si and the constituent elements of Group 1A and Group VA, and the ratio of the constituent elements other than S1 is continuous near the interface of each layer. It is characterized by the presence of parts that change.

In addition to 8i and elements of group 1A or group VA as the constituent elements of all the layers, C and H may be halodane.

The blocking layer may be a single layer, or more preferably two layers. In this case, the concentration of Group 1A or Group VA elements in the 1F locking layer (support side) and the 2nd blocking layer makes the optical bandgap of the 2nd blocking layer a little wider than that of the 1st blocking layer. It is preferable to set the first blocking layer to be higher than the second blocking layer because it is advantageous in terms of improving band 1, performance, and retention ability.

Next, a method for manufacturing the photoconductive member of the present invention will be explained.

First, place a conductive support into a vacuum reactor.

The inside of the reaction vessel is evacuated to 101 to 10<-4 >iorr using a mechanical booster pump and an oil diffusion pump. At this time, the support is maintained at a temperature of 100 to 400°C.

Next, a gas containing 81 atoms in one reaction vessel, e.g.
1H,,81! H6, SIF.

A doping gas containing a Group 1A element or a Group VA element, and if necessary, a gas containing a C atom such as CH, etc. are introduced at a desired mixing ratio, and the mixture is heated to a temperature of 0.1 to 1 torr.
Adjust the exhaust speed of the exhaust system to achieve a pressure of
Wait until steady state is achieved. Next, a 13.56 MHz high frequency power is applied between the electrodes in one reaction vessel to sequentially form a bronking layer, a photoconductive layer and a surface coating layer on the support. At this time, by sequentially adjusting the ratio of the doping gas or the ratio of the gas containing C atoms as necessary, it is possible to continuously change the ratio of the constituent elements near the interface of each layer.

Note that by exciting the doping gas in advance with electromagnetic waves such as fibrous waves, it is possible to improve doping efficiency and film formation speed.

- Therefore, the photoconductive member according to the second invention includes a blocking layer containing common constituent elements of at least St, Group 1A, and Group VA, a photoconductive layer, and a surface coating layer all sequentially laminated on a support, In addition, since the structure has a portion where the ratio of the constituent elements continuously changes near the interface of each layer, it is possible to reduce the strain difference between each layer, prevent delamination between layers, and achieve a long life. In addition, the layer structure is changed from the support side to 81 and 1A.
a blocking layer that includes at least a group VA in common;
By forming the photoconductive layer and the surface coating layer, it is possible to obtain a photoconductive member having the same charging ability and holding ability as conventional ones.

The blocking layer is divided into two layers, and the conductive impurity V content ratio is adjusted to ρN so that the second blocking layer has a smaller optical band gap than the first blocking layer.

By using C-containing amorphous silicon carbide as the second pronging layer, it is possible to obtain a photoconductive member that has significantly higher chargeability and retention ability than conventional photoconductive members. Also, the photoconductive layer.

By using p-type or n-type amorphous silicon carbide containing Group VA and C as the parent material of Group 1A, the resistivity can be reduced to 1O.
It has a high mobility of 11 to 10 11 Ω, and the same mobility is superior to that of ordinary amorphous silicon. One! ,vinegar.

When amorphous silicon carbide is made into an undoped intrinsic semiconductor, the specific resistance is often low, and even if a blocking layer is provided, the resistivity is 1! Carriers generated by light tend to travel not only in the thickness direction but also in the lateral direction, causing blur in an image. Note that amorphous silicon carbide is a material in which the number of bonds between Sl and C is extremely small compared to the number of bonds between 0 Si and 81 or Sl and H.

[Embodiments of the invention]

Next, an embodiment of the present invention will be described with reference to the drawings.

First, a conductive support 1 made of Al is placed in a vacuum reaction container.
The inside of the reaction vessel was brought to a vacuum of 10-3 to 1 O-' torr using a mechanical booster pump and an oil rotary pump. At this time, the support 1 was maintained at a temperature of 100 to 400°C. Subsequently, in one reaction vessel, the flow rate of B, H, /811 (, is 1X10-'').

CH4/ 81 8 so that the flow rate ratio of H4 is 8%
, I H4HBt Ha1 and CH, were introduced.

The exhaust speed of the exhaust system was adjusted so that the reaction pressure was Q, 5 torr. Continuing, when the reaction pressure reached a steady state, 200 W of high frequency power of 13.56 MHz was applied between the electrodes of one reaction container, and this state was maintained for 5 minutes. In 5 minutes, Hs / 8 l Ha increased to 5X10- The mixing bus is successively adjusted and introduced so that the flow rate decreases to the flow rate ratio of
10-”atan%, c/C s t is 1.0ato
A first blocking layer 2 made of m% amorphous silicon carbide was formed.

Next, Hs was given under the same high frequency power and the same reaction pressure.
/ 81 Has CHa / 81 I (a After holding for 5 minutes without changing the flow rate, CH, / 81 in 5 minutes
8 i H to reduce H, to about 0.01%
A mixed gas of 4 m Bt Ha and CH4 was gradually regulated and introduced.

2 μm thick on the first pronking layer z.

B/B+8 + layer maximum value is lXl0-' atom%
.

A second blocking film 11i13 made of amorphous silicon having a maximum layer value of 1.0 mtom% of C/C+81 was continuously formed.

Next, under the same high frequency power and the same reaction pressure, B, H
, /5ir-14, CH, /8th (, 81H without changing the flow rate ratio of 5x10", about 0.01%.

s A mixed gas of BtH@ and CH was introduced for 2 hours.

15 μm thick SB/B 10s on mud 2 blocking #3
1=lX10" atom%, C/C+81=2 Q, B from Qlatom% amorphous silicon carbide
, I(,/81H, flow rate ratio IX1.O-',
The flow rate ratio of CD4/81H decreased to about 300%,
81 H4# Bt ”+1 and CH, f to increase f
Adjust sequentially and introduce high-frequency power for only the last minute.
0 W was applied to the photoconductive layer 4 to a thickness of 0.1 μm.

The maximum layer value of B/B+s+ is 5 X 10-' atom
%, the maximum layer value of C/C+81 is 20 atom%
Surface coating layer 5'! ) A photoreceptor was manufactured by continuously forming a film (as shown in FIG. 1). Incidentally, a model for the amount of work in the thickness direction of such a photoreceptor is shown in FIG. In addition, O in Figure 3...
・・o is 81) T,, o-, is B, H, (2000pp
nl), 0---0 is B, Ha (20ppm
) I WFicH, and these gases are set at flow rates as shown in the table below.

3 4 However, in the electrophotographic photoreceptor of this example, there was no peeling between the layers, and a surface potential of 500 V was obtained under the condition that the charge flowing from the charger to the drum due to corona discharge was 0.4 μc/m. The withstand voltage against developing bias is over 1500V, which is a significant improvement compared to the conventional product, which had parts that caused dielectric breakdown at 200V.Furthermore, good images were obtained even after repeated use of 1 million sheets. was obtained, and it was confirmed that it had a sufficiently long life.

Note that in the above embodiments, the first blocking layer, the second blocking layer
Even when the following conditions were set for the blocking layer, photoconductive layer, and surface coating layer, a photoreceptor having similar effects could be obtained.

(1) The flow rate of the first blocking layer B, H, /S i H, is set to lXl0-'~
l×10-”, the same proportion of CH4/8 tH4 is 10
~100% B/B+81 = I X 10-”
~l atom%, C/C+8i=0.1~JQ
A first blocking layer of 1 atom % is deposited.

5 (II) Second blocking layer Bt Hll /'8 t H4 equal proportion'k l X
i O-' ~ I XI O-', CH, /8 tH
Set the same ratio of 4 to 10-100% and B/B+81 =
5.0XlO-” atom% or less, c/c+st=
Deposit a $2 blocking layer of 0.1-50 atom%.

(ill) Photoconductive layer B, H, /s eyes i, o same proportion t IXI O-' ~
The same ratio of I Xi O-', CH4/s tH, is 5
0% or less (but not less than I
/B+81=5. OX 10-atcm% or less, C
/C+81=0.05 atom% or less photoconductive layer gold film deposition.

(lv) The same proportions of surface coating layers B, H, /8iH,
10-', CH4/81H, the same ratio is 100% or more, B/B + 8i = 5.0XIO" atom% or less,
A surface coating layer of C/C+8i=10 atom% or more is formed.

〔Effect of the invention〕

As described in detail above, according to the present invention, the charging ability and the holding ability are improved to the same level or more than the conventional ones.

6. It is also possible to provide a photoconductive member which is effective as a photoreceptor for electrophotography and has an improved service life by preventing delamination.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of a photoreceptor manufactured in an example of the present invention, Figure 2 is a diagram showing an energy model in the thickness direction of the photoreceptor in Figure 1, and Figure 3 is a cross-sectional view of a photoreceptor manufactured in an example of the present invention. 8iH,,B! H6, CH. It is a figure showing a flow rate model of. J...Support, 2...First blocking layer, 3...
・Second blocking layer, 4...Photoconductive layer% 5...
・Surface coating layer. Applicant's agent Patent attorney Takehiko Suzue7

Claims (1)

Claims: a) A photoconductive member having sequentially a blocking layer and a photoconductive layer on a support, wherein the blocking layer and the layer of photoconductive material are at least 8i and Group 1A or V
1. A photoconductive material, characterized in that it contains a constituent element in common with Group A, and has a portion in which the ratio of the constituent elements other than 81 changes continuously near the interface of each layer. (21) The blocking layer is composed of a first blocking layer and a second blocking layer, and the concentration of the group VA element in the first blocking layer is set to 1, which is higher than that in the second blocking layer. A photoconductive member according to claim 1, characterized in that (31) all the layers contain at least one of C and H or halogen in addition to Si and Group 1A or Group VA. The photoconductive member according to claim 1, characterized in that the photoconductive member comprises: