JP2002287124A - Substrate for liquid crystal device, liquid crystal device, electronic appliance and method for manufacturing substrate for liquid crystal device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a substrate for a liquid crystal device prolonging operable time with a battery by utilizing external light. SOLUTION: The substrate for the liquid crystal device 10 is constructed by forming a photocell 20 on a projecting and recessing face 15 of a substrate 14, by forming a color filter 27 on the photo-electric cell 20 and by forming a transparent conductive film 28 on the color filter 27. The transparent conductive film 28 is optionally formed as pixel electrodes corresponding to respective pixels in a liquid crystal display and having active elements electrically connected thereto and the photocell is optionally formed corresponding to respective pixel electrodes.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a substrate for a liquid crystal device having a photovoltaic cell, a liquid crystal device using the same, and a method of manufacturing a substrate for a liquid crystal device.

[0002]

BACKGROUND OF THE INVENTION In recent years,
Portable electronic devices such as mobile phones, notebook computers, mobile computers, mobile information terminals, video cameras, and digital cameras have become very popular. Since such a portable electronic device is driven by a battery at least when it is carried, the length of time that can be driven without charging is an important point.

[0003] Therefore, various technologies for suppressing power consumption are incorporated in portable electronic devices in order to extend the driving time by battery driving. One of them is to use a liquid crystal device as a display device. Liquid crystal devices are characterized in that they consume less power than other display devices, but nevertheless account for a large proportion of power consumption in portable electronic devices. Therefore, further reduction in power consumption of the liquid crystal device has been attempted. However, at each point of technological development, there is a technically achievable limit in reducing the power consumption of the liquid crystal device itself.

On the other hand, since portable electronic devices are frequently used outdoors and the like, the liquid crystal device is more likely to receive intense light than electronic devices installed indoors.

The present invention has been made in view of the above points, and has as its object to use a liquid crystal device which can extend the operable time by a battery by utilizing external light. To provide a liquid crystal device substrate, a liquid crystal device, an electronic device, and a method of manufacturing a liquid crystal device substrate.

[0006]

(1) A substrate for a liquid crystal device according to the present invention comprises a substrate having an uneven surface, a photovoltaic cell arranged on the irregular surface, and a transparent conductive film arranged on the photocell. And having the following.

According to the present invention, since the substrate for a liquid crystal device is provided with a photovoltaic cell, the substrate for a liquid crystal device can generate power from the photovoltaic cell that receives light from the outside. Therefore, in a liquid crystal device using this liquid crystal device substrate,
In addition to consuming power to perform the display, the battery etc. can be charged with the power from the photocell,
The operating time by a battery or the like can be extended.

Further, since the photovoltaic cell is formed on the uneven surface of the substrate, the area of the light receiving portion of the photovoltaic cell is increased as compared with the case where the photocell is formed on a flat surface, and the amount of power generation can be increased. (2) The transparent conductive film may be disposed as a pixel electrode corresponding to each pixel in a liquid crystal display, and the photovoltaic cell may be disposed corresponding to each of the pixel electrodes.

(3) An active element electrically connected to the pixel electrode may be further provided.

(4) A color filter may be further provided between the photovoltaic cell and the transparent conductive film.

(5) The photovoltaic cell may have light reflectivity.

(6) A liquid crystal device according to the present invention is a liquid crystal device in which a liquid crystal is sandwiched between a pair of substrates for a liquid crystal device. It is characterized in that it is used as one of the substrates.

According to the present invention, since the liquid crystal device substrate is provided with a photovoltaic cell, power can be consumed for display, and a battery or the like can be charged by the power from the photovoltaic cell. The driving time of the device can be extended. In addition, since the photovoltaic cell is formed on the uneven surface of the substrate, the area of the light receiving portion of the photovoltaic cell increases and the amount of power generation increases as compared with the case where the photovoltaic cell is formed on a flat surface. large.

(7) An electronic apparatus according to the present invention includes the liquid crystal device as a display unit.

According to the present invention, since the substrate for the liquid crystal device is provided with a photovoltaic cell, it consumes power for display and can charge a battery or the like with the power from the photovoltaic cell. The driving time of the device can be extended. In addition, since the photovoltaic cell is formed on the uneven surface of the substrate, the area of the light receiving portion of the photovoltaic cell increases and the amount of power generation increases as compared with the case where the photovoltaic cell is formed on a flat surface. large.

(8) A method for manufacturing a substrate for a liquid crystal device according to the present invention is a method for manufacturing a substrate for a liquid crystal device used for a liquid crystal display panel, comprising the steps of forming a substrate having an uneven surface by chemical treatment. A step of forming a photovoltaic cell on the uneven surface; and a step of forming a transparent conductive film on the photovoltaic cell.

According to the present invention, since the uneven surface is formed on the substrate by the chemical treatment, the pitch and depth of the unevenness can be easily controlled to manufacture the substrate for the liquid crystal device.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below more specifically with reference to the drawings.

1. <First Embodiment> 1.1 Liquid Crystal Device and Liquid Crystal Device Substrate FIG. 1 is a schematic exploded sectional view showing a liquid crystal panel 40 as a liquid crystal device of the present embodiment. The liquid crystal panel 40 holds the liquid crystal 3 between the liquid crystal device substrate 10 and the liquid crystal device substrate 35.
Reference numeral 3 denotes an STN-type passive matrix liquid crystal panel 40 in which the liquid crystal panel 3 is enclosed. The liquid crystal device substrate 35 includes a non-facing region 36 that does not face the liquid crystal device substrate 10, and an IC that drives the liquid crystal panel 40 is provided in the non-facing region 36.
Are mounted, and connection terminals are provided. The liquid crystal device substrate 10 includes a layer of a photovoltaic cell 20 and a layer of a transparent conductive film 28 that is one electrode for controlling liquid crystal on the inner surface side. The polarizing plate 6 is arranged outside the liquid crystal device substrate 35, and between the polarizing plate 6 and the liquid crystal device substrate 35,
Phase difference plate 8 for correcting coloring accompanying the STN liquid crystal
Is arranged.

FIG. 2 is a schematic partial sectional view showing the liquid crystal device substrate 10 in more detail. As shown in this figure, a liquid crystal device substrate 10 is a substrate 14 having an uneven surface 15.
And a photovoltaic cell 20 formed on the uneven surface 15 of the substrate 14
And a flattening film 26 formed on the photovoltaic cell 20, a color filter 27 formed on the flattening film 26, and a transparent conductive film 28 formed on the color filter 27. Note that one of the flattening film 26 and the color filter 27 may not be provided. When the color filter 27 is not provided, a transparent conductive film 28 is formed on the flattening film 26.

The substrate 14 may be made of transparent glass or synthetic resin, opaque silicon or ceramic. When silicon is used as the substrate 14, it is preferable to provide an insulating layer formed of, for example, a silicon oxide film between the substrate 14 and the back electrode 21.

The photovoltaic cell 20 is formed as a pn junction type photovoltaic cell, and has a back electrode 21 formed on the substrate 14.
, A p-type amorphous silicon layer 22, an n-type amorphous silicon layer 23, and a surface electrode 24.

The main absorption wavelength band of the photovoltaic cell 20 is outside the visible light region, and it is preferable that the photovoltaic cell 20 has a high reflectance for visible light. As a result, the visible light input from the outside is sufficiently reflected by the photovoltaic cell 20, so that the liquid crystal panel 40 using the liquid crystal device substrate 10 can perform reflective display with sufficient brightness.

A large number of transparent conductive films 28 are provided in parallel in a strip shape. The transparent conductive film 28 is made of, for example, ITO (In
dium Tin Oxide) film. Although only a few transparent conductive films 28 are shown in FIG. 2, many transparent conductive films 28 are actually provided corresponding to the resolution of matrix display. Although an alignment film made of polyimide is provided to cover the transparent conductive film 28, it is not shown.

The liquid crystal panel 40 of the present embodiment is preferably used for normally white display.
As a result, the amount of light that passes through the liquid crystal 33 and reaches the photovoltaic cell 20 is greater than that in the case of normally black, so that the amount of power generated by the photovoltaic cell 20 increases.

Since the liquid crystal device substrate 10 of the present embodiment includes the photovoltaic cells 20, the photovoltaic cells that receive external light can generate power. Therefore, in the liquid crystal panel 40 using the liquid crystal device substrate 10, power can be consumed for performing display, and a battery or the like can be charged with the power from the photovoltaic cell 20.
The operating time by a battery or the like can be extended.

The photovoltaic cell 20 is provided on the uneven surface 15 of the substrate 14.
Since it is formed on the upper surface, the area of the light receiving portion of the photovoltaic cell 20 is increased as compared with the case where it is formed on a plane, and the amount of power generation can be increased.

1.2 Method for Manufacturing Liquid Crystal Device Substrate Next, a method for manufacturing the liquid crystal device substrate 10 will be described.

First, as shown in a schematic partial cross-sectional view of FIG. 3, a substrate 14 having an uneven surface 15 in a display area is formed by a chemical solution treatment. Specifically, the substrate 1
The display region on one surface of the substrate 4 is etched with a chemical solution having a different removal rate for each minute portion. This chemical is based on hydrofluoric acid, and depending on the material of the substrate to be treated, for example, nitric acid, sulfuric acid, hydrochloric acid, hydrogen peroxide, ammonium hydrogen difluoride, ammonium fluoride,
Any of ammonium sulfate and ammonium hydrochloride, or a combination of a plurality of them in an appropriate ratio is used. In addition, as the substrate 14, for example, any of soda lime glass, borosilicate glass, barium borosilicate glass, barium aluminosilicate glass, and aluminosilicate glass can be used. As described above, by appropriately adding the above-described auxiliary chemicals to the hydrofluoric acid aqueous solution, the substrate 14 made of the above-described glass material can be used.
Since the etching rate is different for each minute portion, the substrate 14 having the uneven surface 15 can be formed depending on the preparation of the chemical solution, the processing temperature, and the processing time.

Next, a photovoltaic cell 20 is formed on the uneven surface 15 formed on the substrate 14 so as to be in a state shown in a schematic partial sectional view in FIG. That is, first, the back electrode 21 is formed on the uneven surface 15 of the substrate 14 by sputtering of aluminum or the like. Next, an amorphous silicon layer is formed on the back surface electrode 21 by plasma CVD or the like, and a p-type impurity is doped by ion implantation or the like to form a p-type amorphous silicon layer 22, and the amorphous silicon layer is formed by plasma CVD or the like. The n-type amorphous silicon layer 23 is formed by doping n-type impurities on the amorphous silicon layer 22 by ion implantation or the like into the newly laminated amorphous silicon layer. Then, a surface electrode 24 is formed on the n-type amorphous silicon layer 23 by, for example, sputtering and patterning a substance (for example, ITO) having conductivity and light transmittance. The surface electrode 24 has
Instead of using a substance having conductivity and light transmittance, a substance having conductivity (for example, an Al thin film) formed to have a thickness capable of transmitting light may be used.

Next, silicon oxide is laminated on the photovoltaic cell 20 to form a flattening film 26, and further, a color filter 27 is formed on the surface thereof, as shown in a schematic partial cross-sectional view in FIG. And

Then, the transparent conductive film 28 is formed of, for example, ITO. For example, the transparent conductive film 28 has a thickness of 30 to 20.
It is formed by sputtering ITO to 0 nm and then patterning by wet etching with an aqua regia-based etchant or hydrobromic acid. Note that the etching may be dry etching using a methane-based etching gas.

The substrate 10 for a liquid crystal device of the present embodiment including the steps described above is formed as shown in a schematic partial cross-sectional view in FIG.

According to the manufacturing method of the present embodiment, since the uneven surface is formed on the substrate by the chemical solution treatment, the pitch and depth of the unevenness can be easily controlled to manufacture the liquid crystal device substrate 10.

2. Second Embodiment The second embodiment is different from the first embodiment in that a large number of fine openings are provided in the back electrode of the photovoltaic cell, and the liquid crystal device is formed as a transflective liquid crystal device. In the following, the first
The description will focus on the differences from the embodiment. The other points are the same as in the first embodiment, and a description thereof will be omitted. Corresponding parts in the drawings are denoted by the same reference numerals.

FIG. 6 is a schematic exploded sectional view showing a liquid crystal panel 46 as a liquid crystal device according to the second embodiment. As shown in this figure, since the liquid crystal panel 46 of the present embodiment is formed as a transflective type, a polarizing plate 54 is also arranged on the back side of the liquid crystal device substrate 50. A light guide plate 60 that guides light from the light source 58 toward the display area of the liquid crystal panel 50 is disposed on the back side of the polarizing plate 54.

FIG. 7 is a partial sectional view showing the liquid crystal device substrate 50 in further detail. The substrate 50 for a liquid crystal device of the present embodiment uses a transparent material, for example, glass or synthetic resin, as the substrate 14.
Have many fine openings 53. Accordingly, light from the light guide plate 60 can pass through the photocell through these openings and reach the liquid crystal. As a result, the liquid crystal panel 46 of the present embodiment can also perform transmissive display, and becomes a transflective type. Note that these openings 53 may be filled with a transparent material, for example, silicon oxide.

Further, a large number of openings 53 provided in the back electrode 52 of the photovoltaic cell 51 are formed so as to penetrate the upper p-type amorphous silicon layer 22, the n-type amorphous silicon layer 23, and the front electrode 24. The amount of light transmitted from the side may be further increased. Such an opening 53 can be formed by, for example, anisotropic etching using laser light. Further, it is desirable that the opening 53 be provided at a position corresponding to each pixel.
Thus, light from the back side can be efficiently used for image display.

Since the liquid crystal device substrate 50 of the present embodiment also includes the photovoltaic cell 51 as in the case of the first embodiment, power can be generated by the photocell 51 that receives light from the outside. Therefore, the liquid crystal device substrate 50
In the liquid crystal panel 46 using, power is consumed for performing display, and a battery or the like can be charged with the power from the photovoltaic cell 51, so that the driving time by the battery or the like can be extended. In the liquid crystal device substrate 50 of the present embodiment, even in a transmission mode in which display is performed using light from the light guide plate disposed on the rear surface, a battery or the like is generated by the power generated by the photovoltaic cell 51 by the light from the light guide plate 60. Can be charged.

The photovoltaic cell 51 is provided on the uneven surface 15 of the substrate 14.
Since it is formed on the upper surface, the area of the light receiving portion of the photovoltaic cell 51 is increased as compared with the case where it is formed on a plane, and the amount of power generation can be increased.

Further, according to the present embodiment, the photovoltaic cell 51
Can be formed in the display area.

3. Third Embodiment The third embodiment is different from the first embodiment in that a transparent conductive film is formed as a pixel electrode corresponding to each pixel, and an active element is provided for each pixel electrode. In the following, the points that are different from the first embodiment will be mainly described. The other points are the same as in the first embodiment, and a description thereof will be omitted. Corresponding parts in the drawings are denoted by the same reference numerals.

FIG. 8 shows a substrate 7 for a liquid crystal device according to the third embodiment.
FIG. 4 is a schematic partial cross-sectional view showing a line 0; In the liquid crystal device substrate 70 of the present embodiment, a transparent conductive film is formed as a pixel electrode 72 corresponding to each pixel. Each pixel electrode 7
2 includes an active element 74 provided for each pixel electrode 72, for example, a TFT (Thin Film Transistor) or a TFD (Th
in Film Diode) is connected.

A liquid crystal panel as a liquid crystal device can be formed by sandwiching liquid crystal between the liquid crystal device substrate 70 of the present embodiment and the opposing liquid crystal device substrate. Note that the formed liquid crystal panel is a liquid crystal panel using a switching element for each pixel electrode 72, that is, an active matrix liquid crystal panel. In an active matrix type liquid crystal panel, a TN type liquid crystal is often used as a liquid crystal. When the liquid crystal panel is formed by using the TN type liquid crystal, a phase difference plate is not required unlike the first and second embodiments.

Since the liquid crystal device substrate 70 of the present embodiment also includes the photovoltaic cell 20 as in the case of the first embodiment, power can be generated by the photocell that receives external light. Therefore, in the liquid crystal panel using the liquid crystal device substrate 70, power can be consumed for performing display, and a battery or the like can be charged by the power from the photovoltaic cell 20, and the driving time by the battery or the like can be extended. Can be.

The photovoltaic cell 20 is provided on the uneven surface 15 of the substrate 14.
Since it is formed on the upper surface, the area of the light receiving portion of the photovoltaic cell 20 is increased as compared with the case where it is formed on a plane, and the amount of power generation can be increased.

Further, according to the present embodiment, the photovoltaic cell 21
Can be formed in the display area.

4. <Fourth Embodiment> A fourth embodiment is different from the third embodiment in that a photovoltaic cell is formed as an independent individual cell corresponding to each pixel electrode. The following description focuses on the differences from the third embodiment. The other points are the same as in the third embodiment, and the description is omitted. Corresponding parts in the drawings are denoted by the same reference numerals. FIG. 9 is a schematic partial cross-sectional view showing a liquid crystal device substrate 80 of the fourth embodiment. As shown in this figure, in the liquid crystal device substrate 80 of the present embodiment, the photovoltaic cells 82 are formed as independent cells corresponding to the respective pixel electrodes 72. Each of the photovoltaic cells 82 is insulated by, for example, a silicon oxide layer 84.
It is continuous. In the manufacture of the liquid crystal device substrate 80 of the present embodiment, after stacking the layers constituting the photovoltaic cell 82, separating the photovoltaic cell by, for example, anisotropic etching using a laser, filling the etched region with silicon oxide. Formed.

A liquid crystal panel as a liquid crystal device can be formed by sandwiching liquid crystal between the liquid crystal device substrate 80 of the present embodiment and the opposing liquid crystal device substrate.

Since the liquid crystal device substrate 80 of the present embodiment also includes the photovoltaic cells 82 as in the case of the first embodiment, power can be generated by the photocells 82 that have received external light. Therefore, this liquid crystal device substrate 80
In the liquid crystal panel using, power is consumed for performing display, and a battery or the like can be charged with the power from the photovoltaic cell 82, so that the driving time by the battery or the like can be extended.

The photovoltaic cell 82 is provided on the uneven surface 15 of the substrate 14.
Since it is formed on the upper surface, the area of the light receiving portion of the photovoltaic cell 82 is increased as compared with the case where it is formed on a plane, and the amount of power generation can be increased.

Further, according to the present embodiment, the photovoltaic cell 82
Can be formed in the display area.

5. Fifth Embodiment A fifth embodiment is characterized in that a photovoltaic cell is formed on a liquid crystal device substrate provided with a transparent conductive film over the entire display region, and that the transparent electrode is formed so as to also serve as a surface electrode of the photovoltaic cell. Different from the third embodiment. The following description focuses on the differences from the third embodiment. The other points are the same as in the third embodiment, and the description is omitted. Corresponding parts in the drawings are denoted by the same reference numerals.

FIG. 10 is a schematic partial sectional view showing a liquid crystal device substrate 86 of the fifth embodiment. As shown in this figure, in a liquid crystal device substrate 86 of the present embodiment, a transparent conductive film 87 also serving as a surface electrode of a photovoltaic cell 88 is formed over the entire display region. After the n-type amorphous silicon layer 23 constituting a part of the photovoltaic cell is laminated, the transparent conductive film 8 is formed by, for example, further sputtering ITO.
7 are laminated.

A liquid crystal panel as a liquid crystal device can be formed by sandwiching liquid crystal between the liquid crystal device substrate 86 of the present embodiment and the opposing liquid crystal device substrate. In the present embodiment, a liquid crystal device substrate provided with a transparent conductive film serving as a pixel electrode connected to each active element is used as the opposing liquid crystal device substrate. For example, in the liquid crystal device substrate 70 shown in FIG. 8, each of the layers constituting the photovoltaic cell 20 may be removed, and the respective upper layers may be formed directly on the substrate 14. A color filter is also provided on the liquid crystal device substrate as needed. In the case of the present embodiment, the substrate on which the active elements are formed is made of a light-transmitting substance such as glass.

Since the liquid crystal device substrate 86 of this embodiment also includes the photovoltaic cells 88 as in the case of the first embodiment, power can be generated by the photovoltaic cells 88 that receive external light. Therefore, this liquid crystal device substrate 86
In the liquid crystal panel using, power is consumed for displaying, and a battery or the like can be charged with the power from the photovoltaic cell 88, so that the driving time by the battery or the like can be extended.

The photovoltaic cell 88 is provided on the uneven surface 15 of the substrate 14.
Since it is formed on the upper surface, the area of the light receiving portion of the photovoltaic cell 88 is increased as compared with the case where it is formed on a plane, and the amount of power generation can be increased.

Further, in the liquid crystal device substrate 86,
The transparent conductive film 87 as an electrode for controlling the liquid crystal is
Since the surface electrode also serves as the surface electrode 8, the structure can be simplified and the time required for manufacturing can be shortened.

6. <Electronic Device Using Liquid Crystal Panel> FIGS. 11A, 11B, and 11C illustrate an example of an electronic device using a liquid crystal panel 40 as a liquid crystal device of the first embodiment as a display unit. FIG. Note that the liquid crystal panel is not limited to the liquid crystal panel of the first embodiment, and a liquid crystal panel of another embodiment can be used. FIG. 11A shows a mobile phone 88 having a liquid crystal panel 40 above the front surface thereof. FIG. 11B shows a wristwatch 92, in which a display unit using a liquid crystal panel 40 is provided at the center of the front of the main body. FIG. 11C illustrates a portable information device 96 including a display unit including the liquid crystal panel 40 and an input unit 98. These electronic devices include various circuits such as a display information output source, a display information processing circuit, and a clock generation circuit, and a power supply circuit that supplies power to those circuits, although not shown, in addition to the liquid crystal panel 40. It is configured to include a display signal generation unit. For example, in the case of the portable information device 96, a display signal generated by the display signal generation unit based on information input from the input unit 98 is supplied to the display unit to form a display image.

The electronic devices in which the liquid crystal panel 40 of the present embodiment is incorporated are not limited to the above-described devices, but may be any of various types such as a notebook computer, an electronic organizer, a pager, a calculator, a POS terminal, an IC card, and a mini disk player. Electronic devices are conceivable.

7. <Modifications> 7.1 In each of the above-described embodiments, the liquid crystal device substrate including the pn junction type photovoltaic cell in the display area and the liquid crystal device using the same have been described. However, photovoltaic cells include Schottky barrier solar cells, heterojunction cells, heteroface junction solar cells, pin type solar cells,
Alternatively, it may be a field effect solar cell.

7.2 In each of the embodiments described above,
The liquid crystal panel has the optical characteristics of the STN type and the TN type. The liquid crystal panel that can be used in the present invention is not limited to these, and liquid crystal panels of various other optical characteristics such as a guest host type, a phase transition type, and a ferroelectric type can be used.

7.3 The present invention is not limited to the above embodiments, and various modifications can be made within the scope of the present invention or within the equivalent scope of the claims. .

[Brief description of the drawings]

FIG. 1 is a schematic exploded sectional view showing a liquid crystal panel according to a first embodiment.

FIG. 2 is a schematic partial sectional view showing a liquid crystal device substrate in detail.

FIG. 3 is a schematic partial sectional view illustrating a manufacturing process of the liquid crystal device substrate.

FIG. 4 is a schematic partial cross-sectional view illustrating a manufacturing process of a liquid crystal device substrate.

FIG. 5 is a schematic partial sectional view illustrating a manufacturing process of the liquid crystal device substrate.

FIG. 6 is a schematic exploded sectional view showing a liquid crystal panel according to a second embodiment.

FIG. 7 is a schematic partial cross-sectional view showing a liquid crystal device substrate in detail.

FIG. 8 is a schematic partial cross-sectional view illustrating a liquid crystal device substrate according to a third embodiment.

FIG. 9 is a schematic partial sectional view showing a liquid crystal device substrate according to a fourth embodiment.

FIG. 10 is a schematic partial cross-sectional view showing a liquid crystal device substrate according to a fifth embodiment.

11A and 11B are external views illustrating an electronic device using the liquid crystal panel according to the first embodiment, in which FIG. 11A is a mobile phone,
(B) is a wristwatch, and (C) is a portable information device.

[Explanation of symbols]

 10, 50, 70, 80, 86 Substrate for liquid crystal device 14 Substrate 15 Uneven surface 20, 51, 82, 88 Photovoltaic cell 40, 46 Liquid crystal panel 72 Pixel electrode 74 Active element 90, 92, 96 Electronic equipment

Claims (8)

[Claims] 1. A substrate for a liquid crystal device, comprising: a substrate having an uneven surface; a photovoltaic cell arranged on the irregular surface; and a transparent conductive film arranged on the photocell. 2. The liquid crystal display according to claim 1, wherein the transparent conductive film is disposed as a pixel electrode corresponding to each pixel in a liquid crystal display, and the photovoltaic cell is disposed corresponding to each of the pixel electrodes. Substrate for liquid crystal device. 3. The liquid crystal device substrate according to claim 2, further comprising an active element electrically connected to the pixel electrode. 4. The substrate for a liquid crystal device according to claim 1, further comprising a color filter between the photovoltaic cell and the transparent conductive film. 5. The liquid crystal device substrate according to claim 1, wherein the photovoltaic cell has light reflectivity. 6. A liquid crystal device having a liquid crystal sandwiched between a pair of liquid crystal device substrates, wherein the liquid crystal device substrate according to claim 1 is used for said pair of liquid crystal device substrates. A liquid crystal device used as one of substrates. 7. An electronic apparatus comprising the liquid crystal device according to claim 6 as a display unit. 8. A method for manufacturing a substrate for a liquid crystal device used for a liquid crystal display panel, comprising: a step of forming a substrate having an uneven surface by a chemical treatment; a step of forming a photovoltaic cell on the uneven surface; Forming a transparent conductive film thereon. A method for manufacturing a substrate for a liquid crystal device, comprising: