TWI780213B - A photovoltaic charger for charging an electronic device, a method for producing the photovoltaic charger, and use of the photovoltaic charger for charging an electronic device - Google Patents

Abstract

The present invention relates to a photovoltaic charger (1) specially adapted for charging an electronic device, comprising a solar cell unit (2) comprising a working electrode comprising a porous light-absorbing layer (10) including dyed TiO₂, a porous first conducting layer (12) for extracting photo-generated electrons from the light-absorbing layer (10), wherein the light-absorbing layer is arranged on top of the first conducting layer, a porous substrate (14) made of an insulating material and extending through the entire solar cell unit, wherein the first conducting layer (12) is formed on one side of the porous substrate (14), a counter electrode including a second conducting layer (16), wherein the second conducting layer is formed on the opposite side of the porous substrate (14), and a conducting medium for transferring charges between the counter electrode and the light-absorbing layer, a encapsulation (5) enclosing the solar cell unit, a first conductor (18) electrically connected to the first conducting layer (12), and at least one second conductor (20) electrically connected to the second conducting layer (16). The photovoltaic charger contains only one single solar cell unit (2) and a boost converter (22) electrically connected to the first and second conductors (18, 20), and the boost converter is adapted to step up the voltage from the solar cell unit while stepping down the current from the solar cell unit.

Description

Photovoltaic charger for charging electronic devices, method for manufacturing the same and use of the photovoltaic charger for charging electronic devices

The present invention relates to a photovoltaic charger especially adapted for charging an electronic device, the use of the photovoltaic charger, and a method for manufacturing the photovoltaic charger.

Solar cells have long been used to convert the energy of light into electricity. A solar panel consists of a plurality of solar cells connected in series and is used to absorb sunlight as an energy source to generate electricity. A large number of solar panels are usually deployed together in a large solar park for generating electricity to a power supply grid.

Solar cells are becoming more efficient and cheaper to manufacture. It is therefore natural for companies to make all types of consumer products powered at least in part by solar cells. Many portable electronic devices today are provided with built-in rechargeable batteries for energy storage, and photovoltaic chargers configured to supply power to the batteries for charging them. A photovoltaic charger or a solar charger uses solar energy to supply power to the devices and to charge batteries. Examples of such portable devices are tablets, mobile phones, headsets, and computers. When the solar cells are used, the battery of the device is replenished so that the time of use before the device needs to be charged from an external source is increased. Depending on the efficiency of the photovoltaic charger and the power consumption of the device, the need to use an external source to charge the device may even have been eliminated, so that the device is then only powered by solar energy. For example, small computers are usually powered solely by photovoltaic chargers.

Photovoltaic chargers on the market today use various types of solar panels, ranging from thin film panels with efficiencies ranging from 7 to 15%, to somewhat more efficient monocrystalline panels offering efficiencies as high as 18%. The efficiency is typically tested using Standard Test Conditions, STC, which is an industry standard for the conditions under which solar panels are tested. In the STC, the irradiation was 1000 W/m ² , the temperature was 25° C., and the air quality was 1.5. For example, a solar panel giving an output power of 200W/m2 has an efficiency of ²⁰ %. These conditions simulate the efficiency of a solar panel outdoors under cloudless summer conditions. The wavelength spectrum of indoor light is different from that of outdoor light. For example, wavelengths outside the visible range typically do not exist in indoor light because glass windows filter UV light and indoor lights primarily produce light in the visible range. Therefore, the efficiency of a solar panel measured under outdoor conditions may not be applicable to indoor conditions. A typical human eye will respond to wavelengths from about 390 to 700 nm, and room light is mostly in the visible spectrum.

In the article "Comparison of Indoor Performance of 12 Commercially Available PV Products by a Simple Model" by Georgia Apostolou et al., it is explained how indoor lighting differs from outdoor lighting. The authors of the article stated that in the case of a double glazed insulating window, the reduction in radiated power at 1 m and 5 m from the window would be around 70% and 97%, respectively. This article shows that today's solar panels lose a large part of their efficiency in indoor lighting. Therefore, one disadvantage about those solar panels is that they have low efficiency at low light intensities.

Other disadvantages associated with existing solar panels for powering electronic devices are that some of them are toxic, have poor mechanical properties, and are expensive.

GB2510451(A) owned by OnBeat Ltd. shows a set of headphones powered by solar cells. A flexible solar panel is disposed on the outer surface of the headband and on the earphones. The headset can also be utilized to power an external device with stored solar energy. To onlookers, it is visually apparent that the OnBeat headband is covered with a panel of solar cells, but the type of solar cell is not specified.

The Battery Just In Case ^™ is a mobile phone case that has a backup battery and several solar panels for charging it. Also visually evident here is a panel of several solar cells on one side of the cover, but the type of solar cells is not specified.

The needs for solar panels used to power consumer products are quite different compared to stationary solar panels used in large solar parks to generate electricity. For example, solar panels in a consumer product need to be more robust, flexible, and able to withstand impacts. Again, they must be able to generate electricity under a variety of light conditions, both indoors and outdoors. Light conditions on different parts of a solar panel may also differ due to partial shading of the solar panel, which reduces the efficiency of the solar panel. It is also desirable that the solar panels have an aesthetic appeal since they are visible to the user.

It should be noted that there are many examples of photovoltaic chargers with a solar panel comprising a plurality of solar cells connected in series for powering portable electronic devices. However, there are several problems with known solar panels for powering portable electronic devices: they are very sensitive to light intensity and angle of incoming light. A solar panel with solar cells connected in series is sensitive to partial shading because if one solar cell is not producing a current, the entire series of solar cells will stop producing power. They are quite sensitive and break easily. For example, crystalline silicon solar cells are brittle and may crack when used in portable electronic devices. Also, the user may not agree with the aesthetics, where most of the product is covered by solar panels with a grid of visible current collectors on the upper side. Therefore, there is a need for improved photovoltaic chargers for portable electronic devices.

WO2013/149787 discloses a dye-sensitized solar cell module having a tandem structure, the tandem structure includes a plurality of dye-sensitized solar cell units arranged adjacent to each other and connected in series. Each battery cell includes a working electrode, a first conductive layer for extracting photon-generated electrons from the working electrode, and an opposing electrode including a second conductive layer for transporting electrons from the opposing electrode to the working electrode. The electrolyte of the electrode, and a series connection element for electrically connecting the opposing electrode to a working electrode of an adjacent battery cell. The solar cell module includes a porous insulating substrate, the first conductive layer is a porous conductive layer formed on one side of the porous insulating substrate, and the second conductive layer is a porous conductive layer formed on The porous conductive layer on the opposite side of the porous insulating substrate, and the series connection element is a conductive layer that penetrates the porous insulating substrate and extends over the first conductive layer of one of the battery cells and the corresponding between the second conductive layers of adjacent battery cells, thereby electrically connecting the first conductive layer of one of the battery cells with the second conductive layer of the adjacent battery cells.

It is an object of the present invention to at least partially overcome the above problems and to provide an improvement in rechargeable batteries adapted for charging electronic devices used in consumer applications, and more particularly for charging such electronic devices photovoltaic charger.

This object is achieved by a photovoltaic charger as defined in claim 1.

The photovoltaic charger comprises a solar cell unit comprising a working electrode comprising a porous light absorbing layer comprising dyed _TiO2 , a porous first conductive layer for The light-absorbing layer extracts photon-generated electrons, wherein the light-absorbing layer is disposed on top of the first conductive layer, a porous substrate made of an insulating material, and extends through the The entire solar cell unit, wherein the first conductive layer is formed on one side of the porous substrate, an opposite electrode, which includes a second conductive layer, wherein the second conductive layer is formed on the porous substrate On the opposite side of the substrate, and a conductive medium for transferring charge between the opposite electrode and the light absorbing layer. The photovoltaic charger further comprises an encapsulation enclosing the solar cell unit, a first conductor electrically connected to the first conductive layer, and at least one second conductor electrically connected to the second conductive layer . According to the invention, the photovoltaic charger comprises only a single solar cell unit and a boost converter electrically connected to the first and second conductors, and the boost converter is adapted to step down the voltage from the solar cell Stepping up the voltage from the solar cell while increasing the current to the cell.

The present invention is based on the understanding that this type of solar cell has excellent properties that make it particularly suitable for charging electronic devices for consumer applications both indoors and outdoors. The invention is also based on the understanding that having only a single solar cell in the photovoltaic charger provides further benefits and makes the photovoltaic charger even more suitable for charging electronic devices for consumer applications.

The photovoltaic charger according to the invention is capable of charging devices when the light conditions are very poor. For example, the photovoltaic charger is capable of charging the electronic device when the only light source is a lamp. This system makes it possible to charge electronic devices indoors at night.

Furthermore, since the photovoltaic charger has only a single solar cell, there will be no problem with partial shading. Even if portions of the surface of the solar cell unit are shaded, the unshaded parts will still generate a current. Therefore, even when the active area of the photovoltaic charger is partially shaded, the photovoltaic charger according to the invention is still able to charge the electronic device. The active area refers to the area of the solar cell unit that contributes to generating electricity when exposed to light.

The first conductor acts as a current collector and collects current from the first conductive layer. The second conductor acts as a current distributor and distributes current to the second conductive layer. The photovoltaic charger has a single expandable solar cell, which can be adapted to a portable electronic device any shape or size. It is not necessary to arrange multiple current collectors across the visible side of the photovoltaic charger, so the absence of multiple visible current collectors results in a visually homogeneous surface. Therefore, the photovoltaic charger can be utilized on the portable electronic device without affecting the design of the device. In other words, a portable electronic device can be powered by the photovoltaic charger when the photovoltaic charger is not visible to bystanders. Another advantage of not having many connecting elements arranged over the surface of the solar cell is that a larger area of the solar cell can be utilized to generate electricity because there are no current collectors that block incoming light device.

Further advantages related to the photovoltaic charger include low cost, impact resistance, flexibility, and independence from the angle of incoming light. A porous light absorbing layer comprising dyed _TiO2 is non-brittle and not dependent on the angle of incoming light. Furthermore, the size of the single solar cell unit is scalable, and thus the size and power of the photovoltaic charger can be adapted to the size and power requirements of different devices to be charged. By increasing the area of the solar cell unit, the power generated by the photovoltaic charger is increased.

The photovoltaic charger includes a boost converter electrically connected to the first and second conductors, and the boost converter is adapted to step up the current from the solar cell while stepping down the current from the solar cell unit. This voltage of the solar cell. Thus, the photovoltaic charger is capable of generating a voltage level sufficient for charging electronic devices in a wide range of different light conditions. Different types of battery systems require different voltage levels. The boost converter makes it possible to provide a rechargeable battery of an electronic device with a voltage level required for that type of battery. The voltage generated by the single solar cell unit is too low to charge certain types of batteries, such as lithium batteries which require about 3.6V. In the prior art, the required voltage is achieved by arranging a plurality of solar cells connected in series. According to the invention, the required voltage is achieved by connecting a boost converter to the single solar cell unit. Therefore, it is feasible to provide a photovoltaic charger capable of charging solar cell units with only one battery that require different voltage levels.

In one feature, the boost converter is configured to convert the output voltage from the solar cell unit to a voltage between 1 and 10V. Thus, the photovoltaic charger is capable of charging batteries, such as lithium or nickel based batteries, used in many types of electronic devices used in consumer applications.

The conductive medium used to transport charge between the counter electrode and the light absorbing layer can be, for example, a liquid, such as a liquid iodide/triiodide electrolyte, a liquid copper complex Either a liquid cobalt complex-based electrolyte, a gel, or a solid material such as a solid hole conductor.

According to a characteristic, the conductive medium is an ion-based electrolyte. The electrolyte can be a liquid, or a gel. An advantage of using an ion-based electrolyte is that it can lead to high long-term stability to the efficiency of the solar cell. Another advantage is that the efficiency of the photovoltaic charger is constant or increases with increasing temperature. Thus, the photovoltaic charger operates well over a wide range of temperatures.

According to an aspect of the invention, the solar cell unit produces more than 5 μW/cm ² measured on the active solar cell area when the light intensity received by the light absorbing layer is 200 Lux. It has been proven through tests that the photovoltaic charger system according to the invention is capable of generating more than 5 μW/cm ² when the light intensity received through the light absorbing layer is 200 lux. Lux is an appropriate unit for measuring light intensity because it measures the intensity of light as perceived by the human eye. Lux is commonly used to measure the intensity of room light, which is mostly within the portion of the electromagnetic spectrum visible to the human eye. It is then appropriate to relate the efficiency of the solar cell to the light intensity measured in lux.

According to an aspect of the invention, when the light intensity received by the light absorbing layer is 200 lux, the solar cell unit generates more than 5.5 μW/cm ² . It has been proven through tests that the photovoltaic charger according to the invention is capable of generating more than 5.5 μW/cm ² when the light intensity received through the light absorbing layer is 200 lux.

According to an aspect of the invention, when the light intensity received by the light absorbing layer is 5000 lux, the solar cell unit generates at least 150 μW/cm ² .

According to an aspect of the invention, when the light intensity received by the light absorbing layer is 20000 lux, the solar cell generates at least 600 μW/cm ² , and preferably at least 700 μW/cm ² . More specifically, when the light intensity received by the light absorbing layer is between 200 to 20000 lux, the solar cell unit can generate at least 5 to 600 μW/cm ² . When the light intensity received by the light absorbing layer increases from 200 to 20000 lux, the power generated by the photovoltaic charger increases substantially linearly. Thus, the photovoltaic charger is capable of generating power under a wide range of different light conditions. The photovoltaic charger operates during poor and excellent lighting conditions, such as indoors under artificial light, outdoors in shade, and when exposed to strong sunlight.

Where substantially linear means that the generated power increases linearly with increasing light intensity at least in a substantial part of the interval 200 to 20000 lux. For example, at intensities between 200 and 1000 lux, the power produced can vary slightly from linear.

According to an aspect of the invention, when the intensity of light received through the light absorbing layer varies between 200 and 50,000 lux, the solar cell generates a voltage that varies less than 40%. For example, when the intensity of light received by the light absorbing layer is varied between 200 and 50000 lux, the solar cell unit generates a voltage that varies less than 0.4V, and preferably less than 0.3V. In the interval of 200 to 50000 lux, the voltage generated by the solar cells is quite uniform. This means that the voltage generated is quite independent of the light intensity. Since the actual situation is that when the light intensity received by the light absorbing layer varies between 200 and 50000 lux, the output voltage from the solar cell has only a small change, so there is no large loss during the conversion. , it is feasible to use a boost converter to step up the voltage for a wide range of different light intensities of.

According to a feature of the invention, the electrolyte system includes ions, such as copper ions, or iodide and triiodide ions. The level of the generated voltage depends on the ions in the electrolyte. For example, if the electrolyte contains copper ions, the solar cell can generate a voltage of about 1 V in an open circuit when the light intensity received by the light absorbing layer is 20,000 lux, and if the electrolyte contains iodide and triiodide ions, the solar cell unit can generate a voltage of 0.65V in an open circuit when the light intensity received by the light absorbing layer is 20000 lux.

According to an aspect of the present invention, when the light intensity received by the light absorbing layer is 200 lux, the solar cell generates a voltage of at least 0.3V in an open circuit.

Furthermore, when the light intensity received by the light absorbing layer is 20000 lux, the solar battery unit generates a voltage less than 1.2V in an open circuit.

According to an aspect of the invention, the boost converter is capable of converting a voltage between 0.25 and 1V to a voltage exceeding 3V, and preferably exceeding 3.5V. Therefore, the photovoltaic charger can be utilized to charge a battery with a load voltage exceeding 3V, for example a lithium battery usually requires a load voltage between 3 and 4, 5V, depending on how the battery is loaded depends.

According to an aspect of the present invention, when the light intensity received by the light absorbing layer increases from 200 to 20000 lux, the current generated by the photovoltaic charger increases linearly.

According to a feature of the present invention, when the light intensity received through the light absorbing layer is 200 lux, the solar cell generates a current of at least 15 μA/cm ² , and when the light received through the light absorbing layer As the light intensity increases from 200 to 20000 lux, the current generated by the solar cell increases linearly. Due to the linearity and the fact that the solar cell does not generate any current when the light intensity is zero and generates a current of at least 15 μA/cm when the light intensity is ²⁰⁰ lux, the solar cell is A current of about 1500 μA/cm ² is generated when the light intensity received by the light absorbing layer is 20000 lux. Thus, the solar cell is capable of generating sufficient power to charge the battery of an electronic device over a wide range of light intensities.

According to a feature of the present invention, the first and second conductive layers include metal or a metal alloy. Metals and metal alloys are good conductors of electricity. Therefore, having the conductive layer made of metal or metal alloy results in little resistive power loss during current collection and distribution when high currents are generated in the solar cell.

According to a feature of the present invention, the first and second conductive layers include titanium or an alloy thereof. The use of titanium is advantageous because it is highly corrosion resistant and can withstand high temperatures in air without significant oxidation, which is advantageous during the manufacture of the solar cell unit.

According to an aspect of the invention, the boost converter is capable of handling currents between 15 and 9000 mA/cm ² . Thus, the boost converter is capable of handling current from the solar cell from 200 lux to 120,000 lux, which is full sunlight.

According to an embodiment of the present invention, the conductive medium includes iodide (I ⁻ ) and triiodide (I ₃ ⁻ ), and the content of triiodide in the conductive medium is between 1 mM and 20 mM. This embodiment makes it possible to achieve high power generation at low light intensities.

According to a feature, the first conductive layer and the porous substrate extend continuously through the entire solar cell unit.

According to a feature of the invention, the porous substrate is a sheet comprising woven microfibers extending through the entire solar cell unit. For example, the woven microfibers are made of glass fibers. The sheet comprising woven microfibers extending across the entire solar cell unit contributes to provide a flexible, twistable, and impact-resistant photovoltaic charger.

According to a feature, the solar cell has a top side facing the light and a bottom side, the first conductor is elongated and is arranged on the bottom side of the solar cell or along the solar cell An edge of the top side of the battery cell extends either, and the first Two conductors are elongated and disposed on the bottom side of the solar cell unit. If the first conductor is arranged along an edge of the top side of the solar cell unit, or at the bottom side of the solar cell unit, concealment is easy and will not be visible to the user of.

According to a feature, the solar cell unit has a top side facing the light and a bottom side, and the first and second conductors are elongate and are arranged on the bottom side of the solar cell unit. Therefore, the first and second conductors are invisible to the user, and the appearance of the top side of the solar cell unit is homogeneous.

According to a feature, the encapsulation comprises a plurality of through-throughs that are physically and electrically connected to the first and second conductors for connecting the photovoltaic device to the external device. In other words, there are penetrations in the package for accessing the power generated by the photovoltaic device. Some type of wiring will go through these penetrations. For example, the first and second conductors may extend from the package through the through-throughs to connect to wiring for powering the external device. Alternatively, wires from outside the package pass through the through-throughs and are electrically connected to the first and second conductors. The through-throughs fit snugly around the wiring through the package so that no gas or liquid can pass through the through-throughs. For example, the through-throughs are openings in the package that fit snugly around the wiring that passes through the package.

According to a feature, the encapsulation comprises an at least partially transparent top sheet covering a top side of the solar cell unit, and a bottom sheet covering a bottom side of the solar cell unit. Encapsulation therein means a covering that is sealed around the solar cell to prevent dust and moisture from entering the solar cell and to prevent electrolyte from inside from leaking out of the device. The purpose of the encapsulation is to maintain the integrity of the solar cell components and solar cell composition.

According to a feature, the first conductor is arranged on the top side of the solar cell unit and extends along an edge of the top side of the solar cell unit. The first conductor may then be covered, eg, with plastic, so that it is invisible to onlookers. Since the first conductor is positioned along the edge, it is easily covered without affecting the efficiency of the photovoltaic charger Or its overall appearance.

According to a feature, the first conductor and the second conductor are arranged on the bottom side of the solar cell unit. Therefore, there will then be no visible wiring on the upper side of the photovoltaic charger. The first and second conductors can be easily hidden by placing the photovoltaic charger on a surface of the device, or on a cover of the device. This means that when the photovoltaic charger is placed on a surface of the device, the first conductor is not visible to the user. This makes it possible to integrate the photovoltaic charger in the device or a covering of the device, so that the user will not even notice that there is a photovoltaic charger integrated in the device. A substantially entire surface of the device may be covered by the photovoltaic charger. Thus, the device, or the entire surface covered by the device, can be utilized to generate electricity without affecting the visible appearance of the device.

According to a feature, the second conductive layer and the porous substrate extend continuously through the entire solar cell unit.

According to a feature, the first conductive layer is non-transparent and extends continuously across the entire solar cell unit. The light absorbing layer extends continuously across the solar cell unit on top of the first conductive layer, except possibly for a small area of the first conductive layer reserved for the first conductor .

According to a feature, the appearance of the top side of the solar cell unit is homogeneous. Since the actual situation is that the photovoltaic charger contains only a single solar cell, the light absorbing layer extends continuously across the solar cell on top of the first conductive layer, and there are no visible conductors extending across the solar cell. The top surface of the battery cell, thus the surface of the top side of the solar cell becomes visually homogeneous. This means that the appearance of the upper side of the photovoltaic charger is homogeneous and not interrupted by any current collectors, or has any change in color. This makes it possible to integrate the photovoltaic charger in the electronic device without compromising the visible appearance of the electronic device. The user may not even notice the photovoltaic charger.

According to a feature, the top side of the solar cell unit is homogeneously black. The _TiO2 of the light absorbing layer is black and achieves a black surface of the solar cell. Due to the fact that the light absorbing layer comprises _TiO2 and extends continuously through the solar cell on top of the first conductive layer, the top surface of the solar cell becomes uniformly black. The top sheet covering the top side of the solar cell unit is preferably configured such that it will not affect the appearance of the top surface. The top sheet is transparent, or at least the portion covering the active area of the solar cell unit is transparent. Therefore, the upper surface of the photovoltaic charger is also uniformly black. An advantage of a homogeneously black light-absorbing active surface is that it has the property of maximal light absorption. Another advantage is that a uniform black surface is aesthetically pleasing and attractive.

According to a feature, the package is made of a transparent plastic. This feature contributes to provide a flexible, twistable, and impact-resistant photovoltaic charger.

According to certain features, the shape and size of the single solar cell unit is adapted to the size and shape of the portable electronic device it powers. Furthermore, the active area of the solar cell unit is adapted to the power required to charge the device.

According to a characteristic, the shortest distance from one side of the active area of the solar cell unit to the other is greater than 1 cm, and preferably greater than 1.5 cm.

According to a feature, the shortest distance from one side of the active area of the solar cell unit to the other is greater than 1.5 cm, and the active area of the solar cell unit is greater than 25 cm ² . Such photovoltaic chargers are for example useful for charging headphones.

According to a characteristic, the shortest distance from one side of the active area of the solar cell to the other is greater than 10 cm. Therefore, the active area of the solar cell is greater than 100 cm ² . Such a photovoltaic charger is useful, for example, for charging a tablet computer.

According to a feature, the portable electronic device is any one of a headset, a tablet computer, or a mobile phone.

According to another feature of the present invention, it includes the use of the above photovoltaic charger for powering a portable electronic device. For example, the portable electronic device is a headset, a mobile phone, or a tablet computer.

According to some features, the portable electronic device is a headset comprising a headband for reaching over a wearer's head, wherein the photovoltaic charger is disposed on the headband on a top surface.

According to some features, the portable electronic device is a tablet computer, wherein the photovoltaic charger is integrated in the tablet computer or a housing of the tablet computer.

According to some features, the portable electronic device is a mobile phone, wherein the photovoltaic charger is integrated in the mobile phone or in a casing of the mobile phone.

According to another feature of the present invention, it includes a method for manufacturing a photovoltaic charger for powering a portable electronic device.

The method comprises: ‧creating a sheet with the single solar cell unit, ‧adapting the shape and size of the single solar cell unit to a surface on which the single solar cell unit will be placed, by cutting the sheet with the single solar cell unit One of the sheets of the solar cell unit has the shape and size, ‧the first conductor is configured to be in electrical contact with the first conductive layer, ‧the second conductor is configured to be in electrical contact with the second conductive layer , ‧ disposing a top sheet and a bottom sheet of the package so that they surround the block of the sheet and at least partially surround the first and second conductors such that the shape and size of the package are adapted to the single solar energy The shape and size of the battery cell, and • sealing the edges of the top sheet and the bottom sheet to form the package.

The method for manufacturing the photovoltaic charger is simple and cost-effective.

According to a feature, the method comprises disposing first and second conductors between the solar cell unit and the encapsulation on the bottom side of the single solar cell unit.

According to a feature, the method includes disposing the first conductor along at least a portion of an edge of the top side, and disposing the at least one second conductor on the bottom side of the single solar cell unit.

1: Photovoltaic charger

1a: Photovoltaic charger

1b: Photovoltaic charger

2: Solar cell unit

3: The first connecting element

4: Second connecting element

5: Encapsulation

5a: top piece

5b: Bottom piece

7a-b: through

10: Light absorbing layer

12: The first conductive layer

14: Porous substrate

16: Second conductive layer

18: First conductor

20: Second conductor

22: Boost Converter

24: Insulation gap

26: through hole

28: Tablet PC

29: shell

30: Headphones

32: headband

The invention will now be illustrated more closely by the description of different embodiments of the invention and with reference to the accompanying drawings.

FIG. 1 is a top view showing a photovoltaic charger according to one or more embodiments of the present invention.

FIG. 2 shows a cross-section through the photovoltaic charger shown in FIG. 1 in an enlarged view.

Figure 3 is a top view showing a portion of a photovoltaic charger according to one or more embodiments of the present invention.

FIG. 4 is a bottom view showing the portion of the photovoltaic charger shown in FIG. 3 .

FIG. 5 is a diagram showing a cross section through the portion of the photovoltaic charger shown in FIG. 3 .

Figure 6 is a cross-section showing a portion through a photovoltaic charger according to one or more embodiments of the present invention.

7 is a graph showing the voltage (mV) generated for light intensities between 200 and 20,000 lux for a first example of a solar cell unit with an electrolyte comprising iodide and tri-iodide ions A plot of the measured values.

Fig. 8 is a graph showing, for the first example of the solar cell, according to the measured values of the generated current (μA/cm ² ) for light intensities between 200 and 20000 lux.

Fig. 9 is a diagram showing measured values of power per area (μW/cm ² ) produced for light intensities between 200 and 20000 lux for the first example of the solar cell unit picture.

FIG. 10 shows the plot of measured values of the generated voltage (mV) for light intensities between 200 and 50000 lux for a second example of a solar cell with an electrolyte comprising copper ions picture.

Fig. 11 is a graph showing, for the second example of the solar cell, according to the measured values of the generated current (μA/cm ² ) for light intensities between 200 and 50000 lux.

Figure 12 is a graph showing for the second example of the solar cell unit according to the measured values of the generated power per area (μW/cm ² ) for light intensities between 200 and 50000 lux .

Figure 13 shows an example of a tablet computer with a photovoltaic charger integrated in a cover for charging the tablet computer.

14 is a top view showing an example of a headset with a photovoltaic charger integrated into a headband of the headset.

15a-b show side views of the headset shown in FIG. 14 .

FIG. 16 is a flowchart showing a method for manufacturing the photovoltaic charger.

Features of the present disclosure will be more fully described below with reference to the accompanying drawings. However, the photovoltaic chargers and methods disclosed herein may be implemented in many different forms and thus should not be construed as limited to the features set forth herein. Like element numbers in the drawings refer to like elements throughout.

The terminology used herein is for the purpose of describing specific features of the disclosure only, and thus is not intended to limit the present invention.

Unless otherwise defined, all terms used herein have the same meaning as this Disclosure The same meaning as commonly understood by those skilled in the art to which it belongs.

Fig. 1 is a top view showing a photovoltaic charger 1 according to an embodiment of the present invention. The photovoltaic charger 1 is especially adapted for powering portable electronic devices such as earphones, laptops, tablets, mobile phones, and remote control units that can be utilized indoors and outdoors. The photovoltaic charger 1 can also be used to power small electronic devices embedded in other physical devices such as vehicles and household appliances called Internet of Things (IoT).

The photovoltaic charger 1 includes a solar cell unit 2 , an encapsulation 5 surrounding the solar cell unit 2 , a first conductor 18 , and a second conductor 20 . The photovoltaic charger may further comprise a connecting element (not shown) for connecting the photovoltaic charger 1 to the electronic device. The solar cell is a dye-sensitized solar cell (DSC). Preferably, the solar cell unit is a monolithic type DSC. The monolithic type of DSC differs from a standard DSC in that it is fabricated on a single substrate on which multiple layers are disposed.

The package includes a plurality of through-holes associated with the first and second conductors for connecting the photovoltaic device to the external device. In other words, there are penetrations in the package for accessing the power generated by the photovoltaic device. Some kind of wiring will go through these penetrations. For example, the first and second conductors may extend from the package through the through-throughs to connect to wiring for powering the external device. Alternatively, wires from outside the package pass through the through-throughs and are electrically connected to the first and second conductors. The through-throughs fit snugly around the wiring through the package so that no gas or liquid can pass through the through-throughs. For example, the through-throughs are openings in the package that fit snugly around the wiring that passes through the package.

The package 5 comprises a plurality of through-throughs 7a-b arranged in relation to the first conductor 18 and the second conductor 20 for connecting the photovoltaic device 1 to the external device, and thereby access the power generated by the photovoltaic device. For example, the feedthroughs are guided through openings in the enclosure. Some type of wiring will pass through these openings. E.g, As shown in Figure 1, the first and second conductors 18, 20 may extend from the package through the through-throughs 7a-b to connect to wiring for powering the external device. Alternatively, wires from outside the package pass through the through-throughs and are electrically connected to the first and second conductors. The penetrations fit snugly around the wiring so that no gas or liquid can pass through it. The penetrations can be made by having wires or conductors that should pass through the holes be in place when the encapsulation is arranged on the solar cell unit 2 . For example, the top sheet 5 a and the bottom sheet 5 b are adhesive films, which are placed together on the solar cell unit 2 . Alternatively, the top and bottom sheets are made of a flexible plastic material, and the edges of the top and bottom sheets are joined to each other by melting the plastic material. If the wires/conductors are already in place between the sheets before the bonding and the edges of the sheets protrude, the penetrations will be created during the bonding. Alternatively, the through-holes include through-holes in the encapsulation made after encapsulation of the solar cell unit. The through holes are sealed after the wire/conductor has been disposed in the through holes. The locations of the penetrations will depend on the locations of the first and second conductors. The number of penetrations can vary. Each of the first and second conductors has at least one through. However, it is also possible that each of the first and second conductors has a plurality of penetrations.

FIG. 2 shows an enlarged cross-section through a part of the photovoltaic charger 1 shown in FIG. 1 . The solar cell unit 2 includes a working electrode comprising a porous light absorbing layer 10 , and a porous first conductive layer 12 for extracting electrons generated by photons from the light absorbing layer 10 . The light absorbing layer 10 includes dyed TiO ₂ . Conventional dyes known in the art can be used. The dye system was chosen to give good efficiency of the solar cell, especially in combination with a copper-based conductive medium. The light absorbing layer may also include silicon (Si) particles, or particles of CdTe, CIGS, CIS, GaAs, perovskite (perovskite) may also be applicable.

The light absorbing layer 10 is disposed on top of the first conductive layer 12 . The solar cell unit 2 further includes a porous substrate 14 made of an insulating material, and a An opposite electrode of the second conductive layer 16 . In this example, the second conductive layer is porous. However, in an alternative embodiment, the second conductive layer need not be porous. For example, the second conductive layer can be made of a metal foil. The first conductive layer 12 is formed on one side of the porous substrate 14 and the second conductive layer 16 is formed on the opposite side of the porous substrate 14 . The first conductive layer 12 is in direct electrical contact with the light absorbing layer 10 . The porous substrate 14 provides electrical insulation between the first and second conductive layers 12 , 16 . The first and second conductive layers 12 , 16 are physically and electrically separated by the porous substrate 14 . The porosity of the porous substrate 14 will enable the transport of ions through the substrate. For example, the thickness of the porous insulating substrate 14 is greater than 4 μm and less than 100 μm. The porosity of the first and second conductive layers 12, 16 will enable transport of ions through the conductive layers.

The porous light absorbing layer 10 is a porous TiO ₂ layer deposited onto the first conductive layer 12 . The TiO ₂ layer system includes the TiO ₂ particles dyed by absorbing dye molecules on the surface of the TiO ₂ particles. The light absorbing layer 10 is arranged on a top side of the solar cell 2 . The top side should face the light to allow the light to hit the dye molecules of the working electrode.

The photovoltaic charger 1 only includes a single solar battery unit 2 . At least the first conductive layer 12 and the porous substrate 14 extend continuously through the entire solar cell unit. The light absorbing layer 10 and the second conductive layer 16 continuously extend through at least a substantial portion of the solar cell unit. In an alternative example, a smaller portion of the light absorbing layer 10 may be removed along an edge of the solar cell to allow a first conductor on a top side of the solar cell 18 can electrically contact the first conductive layer 12 . In another alternative example, a smaller portion of the second conductive layer 16 may be removed to allow the first conductor 18 to make electrical contact with the first conductor 18 from a bottom side of the solar cell unit. Conductive layer 12. In this example, the solar cell unit is filled with an electrolyte for charge transfer between the opposite electrode and the light absorbing layer 10 . The electrolyte is, for example, a conventional I-/I ^{- 3} electrolyte or a similar electrolyte, or a copper (Cu)-based electrolyte, or a cobalt (Co) complex-based electrolyte. The electrolyte system includes ions, such as iodide ions (I ⁻ ) and triiodide ions (I ₃ ⁻ ), or copper ions (Cu ²⁺ and Cu ⁺ ). Sunlight is harvested by the dye, which generates photo-excited electrons, which are injected into the conductive bands of the _TiO2 particles and further collected by the first conductive layer. At the same time, the ions in the electrolyte transport electrons from the second conductive layer to the light absorbing layer 10 . The first conductor 18 collects the electrons from the first conductive layer, and the second conductor provides electrons to the second conductive layer, so that the solar cell unit can continuously generate electricity from the incoming photons.

The electrolyte system runs through the light absorbing layer 10, the first conductive layer 12, the porous substrate 14, and the pores of the second conductive layer 16, so that the ions can be transported in the light absorbing layer 10 and the second conductive layer 16. Between the two conductive layers 16, electrons are transported from the second conductive layer to the light absorbing layer.

There are many dyes available, and according to certain characteristics, the dye family includes triarylamine (triarylamine) organic dyes, which are included in the class of donor-π bridge-acceptor (D-π-A) and in Any one or a mixture of dyes in the class of donor-acceptor-π bridge-acceptor (D-A-π-A). Such dyes give good efficiencies of the solar cells, especially in combination with a copper-based conductive medium. The first class of photosensitizers are, for example, substituted (diphenylaminophenyl)-thiophene-2-cyanoacrylic acids, or substituted (diphenylaminophenyl)-thiophene-2-cyanoacrylic acids, Phenylaminophenyl)cyclopenta-dithiophene-2-cyanoacrylic acids (substituted(diphenylaminophenyl)cyclopenta-dithiophene-2-cyanoacrylic acids). This second class is, for example, substituted (((diphenylaminophenyl)benzothiadiazolyl)-cyclopentadithiyl)aryl/heteroaryl-2-cyanoacrylic acid (substituted (((diphenylaminophenyl)benzothia-diazolyl)-cyclopentadithiophenyl)aryl/heteroaryl-2-cyanoacrylic acids), or (((diphenylaminophenyl)-cyclopentadithiophenyl)benzothiadiazolyl) Aryl/heteroaryl-2-cyano-acrylic acids ((((diphenyl-aminophenyl)-cyclopentadithiophenyl)benzothiadiazolyl)aryl/heteroaryl-2-cyano-acrylic acids).

The first conductor 18 is electrically connected to the first conductive layer 12 , and the second conductor 20 is electrically connected to the second conductive layer 16 . For example, the first and second conductors are made of metal to achieve high conductivity.

The package 5 comprises a top sheet 5a covering a top side of the solar cell unit 2, and a bottom sheet 5b covering a bottom side of the solar cell unit. The encapsulation 5 encloses the solar cell unit and the electrolyte and acts as a liquid barrier for the electrolyte, thus avoiding leakage of the electrolyte from the photovoltaic charger 1 . The top sheet 5 a is transparent, or at least the part covering the active area of the solar cell 2 is transparent. The top sheet 5a on the top side of the solar cell covers the light absorbing layer 10 and allows light to pass through. The top and bottom sheets 5a-b are for example made of a polymer material. A polymer material is strong and impact resistant, yet flexible. The top and bottom sheets 5a-b are sealed at the edges in order to protect the solar cell against the surrounding atmosphere and avoid evaporation or leakage of the electrolyte from inside the solar cell.

The opposite electrode may include a catalyst layer. Alternatively, the second conductive layer 16 may include catalyst particles integrated in the second conductive layer.

For example, the first and second conductive layers 12, 16 are made of a material selected from the group consisting of titanium, titanium alloys, nickel alloys, graphite, and amorphous carbon, or mixtures thereof of. Preferably, the first and second conductive layers 12, 16 are made of metal or a metal alloy to provide high conductivity. Most preferably, the porous conductive layers are made of titanium or a titanium alloy. In this example, the first and second porous conductive layers 12, 16 are made of titanium (Ti).

In one example, the porous substrate is a sheet comprising a fabric with woven microfibers. A microfiber is a fiber having a diameter less than 10 μm and greater than 1 nm. A fabric with woven microfibers can be made to be very thin and mechanically very strong. The fabric with woven microfibers contains holes between the woven yarns. The porous substrate can further include one or more layers of non-woven microfibers disposed on the woven microfibers to at least partially block pores between the yarns. Furthermore, the non-woven layer provides a smooth surface on the substrate, which is suitable for applying a smooth conductive layer on the substrate by printing. The substrate is made of, for example, glass, silicon dioxide (SiO ₂ ), aluminum oxide (Al ₂ O ₃ ), aluminosilicate or quartz. Suitably, the non-woven and woven microfibers of the porous substrate, such as those made of glass fibers, provide a strong and flexible substrate. The thickness of the fabric with woven microfibers is suitably between 4 μm and 30 μm, preferably between 4 μm and 20 μm, to provide the required mechanical strength, while being thin enough to allow ions to pass through the Fast transfer between counter and working electrodes.

In one feature, the light absorbing layer 10 and the first conductive layer 12 are non-transparent. In this example, the upper surface of the solar cell unit 2 is uniformly black, ie as shown in FIG. 1 . The _TiO2 of the light absorbing layer is black. There are no surface conductors extending across the solar cells 2 as in prior art solar cell panels. This is because the photovoltaic charger 1 comprises only a single solar cell, rather than a plurality of solar cells connected in series as in solar panels used in prior art photovoltaic chargers.

The size of the solar cell unit 2 , ie the length and width of the solar cell unit can vary according to which device it is adapted to charge. The active area of the solar cell can then be varied according to the power requirements of the device to be charged. The possible shapes and sizes of the solar cells are not limited. For example, the size of the solar cell can vary from 1 x 1 cm with a 1 cm ² active area to 1 x 1 m with a 1 m ² active area. There is no upper limit to the length and width of the solar cell unit. However, a solar cell unit larger than 1 x 1 m may be too bulky to transport during the manufacture of the solar cell unit.

The photovoltaic charger 1 consists of a single solar cell unit 2 and an electrical connection to The boost converter 22 of the first and second conductors 18 , 20 . A boost converter (also known as a step-up converter or a step-up regulator) is a DC-to-DC power converter that steps up the voltage while stepping down the current from its input to its output. The voltage generated by the single solar cell unit is too low to charge certain types of batteries, such as lithium batteries which require about 3.6V. The boost converter is adapted to step up the voltage from the solar cell 2 while stepping down the current from the solar cell unit. The required voltage level is achieved by connecting a boost converter to the single solar cell unit. Therefore, it is possible to provide a photovoltaic charger with only a single solar cell capable of charging batteries requiring different voltage levels.

The photovoltaic charger 1 comprises connecting elements 3, 4 for connecting the photovoltaic charger 1 to a battery of the electronic device it is charging. The boost converter 22 comprises an input terminal electrically connected to the first and second conductors 18 , 20 and an output terminal electrically connected to the connecting elements 3 , 4 .

The level of the generated voltage depends on the ions in the electrolyte. For example, if the electrolyte contains copper ions, the solar cell 2 generates a voltage of about 1 V in an open circuit when the light intensity received by the light absorbing layer is 20000 lux, and if the electrolyte contains iodine compound and triiodide ions, the solar cell unit generates a voltage of about 0.65V in an open circuit when the light intensity received by the light absorbing layer 10 is 20000 lux. However, when the light intensity received by the light absorbing layer varies between 200 and 20000 lux, the solar cell 2 generates a voltage that varies by at most 0.4V in an open circuit. The requirements on the voltage conversion of the boost converter 22 depend on the voltage requirements of the rechargeable battery. Most rechargeable battery types used in electronic devices for consumer applications require a voltage between 1 and 10V. The boost converter makes it possible to generate a stable voltage at a level required by the rechargeable battery. Preferably, the boost converter 22 is capable of converting the output voltage and current from the solar cell unit to a voltage level between 1 and 10V. Different boost converters can be utilized depending on the desired output voltage. Therefore, the photovoltaic charger 1 series is capable of charging many types of electronic devices installed batteries, such as lithium batteries (3.6V), NiCd and NiMH batteries (1.25V).

It has been shown from tests that the solar cell unit 2 is capable of generating a current of at least 15 μA/cm ² when the light intensity received through the light-absorbing layer is 200 lux, and when the light received through the light-absorbing layer 10 is An intensity of 20,000 lux produces a current of at least 1500 μA/cm ² . Thus, the solar cell unit is capable of generating sufficient power to charge the battery of an electronic device over a wide range of light intensities.

According to certain characteristics, at least the first conductive layer 12 and the porous substrate 14 extend continuously through the entire solar cell unit 2 . The light absorbing layer 10 and the second conductive layer 16 extend continuously through at least a substantial portion of the solar cell unit. In one example, as shown in FIG. 5 , a smaller portion of the light absorbing layer 10 can be removed so that the first conductor 18 on a top side of the solar cell unit 2 has a Direct electrical contact to the first conductive layer. In this example, the top side of the solar cell unit 2 is the top side of the light absorbing layer 10 and the top side of the first conductive layer 12 where the light absorbing layer has been removed. In another example, as shown in FIG. 6, one or more smaller portions of the second conductive layer 16 can be removed so that the first conductor 18 can have a The bottom side is in electrical contact with the first conductive layer 12 .

3-5 show a first example of how to arrange the first and second conductors 18 , 20 on the solar cell unit 2 . FIG. 3 shows a top view of a photovoltaic charger 1a. FIG. 4 shows a bottom view of the photovoltaic charger 1a, and FIG. 5 shows a cross section through the photovoltaic charger 1a. As shown in FIG. 1, the photovoltaic charger 1a may include a boost converter 22 (not shown) electrically connected to the first and second conductors 18, which is adapted to step up the voltage from the solar cell unit. 2 voltage. In this example, as shown in FIG. 3 , the first conductor 18 is electrically connected to the first conductive layer 12 and extends along an edge of the solar cell unit 2 on the top side. As shown in FIG. 4 , the second conductor 20 is electrically connected to the second conductive layer 16 and is arranged on the bottom side of the solar cell unit 2 . For example, the first and second conductors 18, 20 include a conductive foil or a wire. The first conductor 18 is is disposed on the first conductive layer 12 and extends along an edge of the first conductive layer. Therefore, the first conductor 18 does not interfere with the design of the photovoltaic charger, or the device it charges, and can be easily covered. An upper surface of the first conductive layer 12 includes an elongated surface portion facing the top sheet 5a, and the first conductor 18 is provided on the elongated surface portion. The first conductor 18 is in mechanical and electrical contact with the first conductive layer and extends along the elongated surface portion. The end of the light absorbing layer 10 is close to the first conductor 18 and does not cover the elongated portion of the first conductive layer 12 where the first conductor 18 is disposed.

The second conductive layer 16 has a bottom surface facing the bottom sheet 5b. The second conductor is in mechanical and electrical contact with the bottom surface, and the second conductor extends along the bottom surface. In this example, the photovoltaic charger 1 a has only a second conductor 20 . Alternatively, the photovoltaic charger may have a plurality of second conductors extending across the bottom surface of the second conductive layer 16 . In this example, as shown in FIG. 4 , the second conductor 20 extends along an edge of the bottom side of the solar cell unit 2 . However, the second conductor 20 can be configured in many different ways as long as it is in electrical contact with the second conductive layer 16 because the second conductor 20 is not visible from the outside of the photovoltaic charger 1a. of.

The first conductor 18 is elongated and extends between the top sheet 5 a of the encapsulation 5 and the first conductive layer 12 at the top side of the solar cell unit 2 . The second conductor 20 is elongated and extends between the bottom sheet 5b of the encapsulation 5 and the second conductive layer 16 at the bottom side of the solar cell unit. The enclosure is provided with a plurality of inlets connected to the ends of the first and second conductors 18, 20 to allow the photovoltaic charger 1a to be electrically connected to external devices that it will power. The ends of the first and second conductors 18, 20 extend through inlets in the package to the outside of the photovoltaic charger. Suitably, the inlets are arranged between the top and bottom sheets of the package. The conductors 18, 20 extend between the top and bottom sheets near the ends of the photovoltaic charger, and the sheets are sealed around the conductors. This will ease the manufacture of the photovoltaic charger.

FIG. 6 shows a second example of how the first and second conductors 18 , 20 are arranged on the solar cell unit 2 . Figure 6 shows a cross-section through a photovoltaic charger 1b. This example is different from the previous examples in that the first conductor 18 and the second conductor 20 are arranged on the bottom side of the solar cell unit 2 . Therefore, there are no visible conductors on a front side of the photovoltaic charger 1b. The first conductor 18 is disposed between the porous substrate 14 and the bottom sheet 5b. The first conductor 18 is electrically insulated from the second conductive layer 16 . For example, the second conductive layer 16 is terminated at a distance from the first conductor 18 such that an insulating gap 24 is formed between the first conductor 18 and the second conductive layer 16 . In this example, the first conductor 18 extends along an edge of the porous substrate. However, the first conductor 18 can be disposed on the porous substrate 14 in different ways. The first conductor 18 is in electrical contact with the first conductive layer 12 . This can be achieved in different ways. For example, the porous substrate includes a conductive material disposed between the first conductor and the first conductive layer to achieve electrical contact between the first conductor 18 and the first conductive layer 12 . For example, a portion of the porous substrate may include one or more through-holes 26 filled with a conductive material such as conductive particles, or the portion may include conductive particles received in the pores of the porous substrate. , and form a conductive path through the porous substrate. This can be achieved by infiltrating the porous substrate with conductive particles between the first conductor and the first conductive layer. The photovoltaic charger 1b may include a boost converter 22 (not shown) electrically connected to the first and second conductors 18, 20 and adapted to step up the voltage from the solar cell 2, i.e. as Those shown in Figure 1.

Measurements of the generated power per area for different light conditions have been made on an example of a photovoltaic charger of the present invention. In this example, the solar cell unit has a size of 14.5 x 23.4 cm, and an active area of 340 cm ² . The electrolyte system of the solar cell unit includes iodide and triiodide ions, and the first and second conductive layers are made of titanium (Ti). An unloaded photovoltaic charger was exposed to light between 200 and 20,000 lux (lumens per square meter), and the output voltage and output current from the photovoltaic charger were measured. The results of this measurement are shown in Table 1 below. The total power generated is determined from the measured current and voltage, and the power per area generated is determined by dividing the total power by the active area of the solar cell unit.

Table 1 is the power per active area produced for a light intensity between 200-20000 lux for a solar cell unit with an electrolyte comprising iodide (I ⁻ ) and triiodide (I ₃ ⁻ ) ions , measurement of current, voltage and fill factor (ff) per active area. The content of triiodide is between 1mM and 20mM. The iodide system acts as ox, and the triiodide system acts as red.

The performance of the solar cell at different light intensities (intensities measured in lux units) can be measured by shining light on the solar cell and simultaneously sweeping an applied voltage across the solar cell to This is accomplished by measuring and collecting the current-voltage response of the solar cell. The measurements were performed using a warm white LED as the light source.

IV curves collected under illumination provide information on the open circuit voltage, short circuit current, fill factor, the power, and the power conversion efficiency. By collecting IV curves at different light intensities, it is possible to gather information on the light intensity dependence of the open circuit voltage, short circuit current, fill factor, the power and the power conversion efficiency, respectively.

The results from Table 1 are from measurements on a sample of a solar cell. Measurements on different solar cells of this type may vary. For example, the generated power per area might be 5 μW/cm ² to 8 μW/cm ² .

The light source for illuminating on this solar cell can be according to the application of this solar cell Use and change. For indoor applications, it may be useful to use fluorescent bulbs or indoor LED lighting. For solar cell applications utilizing outdoor light, it may be useful to utilize a solar simulator to generate artificial sunlight to shine on the solar cell.

The light intensity of the light source can be measured in different ways, for example by using an illuminometer or a spectroradiometer placed at the same position relative to the light source as the solar cell . In this example, the light intensity is measured using a lux meter.

Table 1 shows the determined power in microwatts per square centimeter (μW/cm ² ) for different light intensities measured in lux. As can be seen from the table, the solar cell produces 6.2 μW/cm ² when the light intensity received by the solar cell is 200 lux and when the light intensity received by the solar cell is 5000 lux 208 μW/cm ² is generated when the solar cell unit receives light intensity of 20000 lux and 730 μW/cm ² is generated. This shows that the photovoltaic charger is capable of generating more than 5 μW/cm ² , and even more than 5.5 μW/cm ² , when the light intensity received by the light absorbing layer is 200 lux. It also shows that the photovoltaic charger system can generate more than 700 μW/cm ² when the light intensity received by the light absorbing layer is 20000 lux. Therefore, when the light intensity received by the light absorbing layer is between 200 to 20000 lux, the solar cell unit can generate at least 5.5 to 700 μW/cm ² . When the light intensity received by the light absorbing layer increases from 200 to 20000 lux, the power generated by the photovoltaic charger increases substantially linearly. Thus, the photovoltaic charger is capable of generating power under a wide range of different light conditions.

FIG. 7 is a graph showing the voltage (mV) generated for light intensities between 200 and 20000 lux according to the measured values of Table 1. FIG. As can be seen from the figure and Table 1, the solar cell was able to generate a voltage of 480 mV in an open circuit when the light intensity received by the solar cell was 200 lux. Furthermore, the photovoltaic charger is able to use the solar cell When the light intensity received by the unit is 20000 lux, a voltage of 650mV is generated in an open circuit. As can be seen from the figure, the resulting increase in voltage is greatest between 200 and 3000 lux. The generated voltage is substantially linear between 3000 and 20000 lux. As can be seen from this Table 1, the difference in voltage generated between 200 and 20000 lux is only 167 mV. Therefore, when the intensity of light received by the light absorbing layer varies between 200 and 20000 lux, the solar cell unit generates a voltage that varies less than 0.2V in an open circuit. Thus, the difference in voltage generated between 200 and 20000 lux is about 35%.

FIG. 8 is a graph showing the generated current (μA/cm ² ) for light intensities between 200 and 20000 lux according to the measured values of Table 1. FIG. As can be seen from the figure, the current increases linearly.

9 is a graph showing the generated power per area (μW/cm ² ) for light intensities between 200 and 20000 lux calculated from the measured voltage and current values in Table 1. FIG. As can be seen from the figure, in the interval 200-20000 lux, the measured power is substantially proportional to the incoming light intensity.

Further measurements of the power per area produced for different light conditions have been made on another example of a photovoltaic charger of the present invention. In this example, the solar cell's electrolyte system included copper ions (Cu ⁺ and Cu ²⁺ ), which was the only difference between the photovoltaic chargers measured. These measurement conditions are the same. An unloaded photovoltaic charger was exposed to light between 200 and 20000 lux (lumens per square meter), and the output voltage and output current from the photovoltaic charger were measured. The results of these measurements are shown in Table 2 below.

Table 2 is the power per area, current per area, voltage and fill factor (ff) produced for a solar cell with an electrolyte comprising copper ions for light intensities between 200-20000 lux Measured; Cu ⁺ is red and Cu ²⁺ is ox.

As can be seen from the Table 2, the solar cell generates 12.8 μW/cm ² when the light intensity received by the solar cell is 200 lux, and when the light intensity received by the solar cell is 5000 lux 498 μW/cm ^{2 is produced at lux, and 2020 μW/cm 2 is} produced when the light intensity received by the solar cell unit is 20000 lux. This shows that the photovoltaic charger is capable of generating more than 12 μW/cm ² when the light intensity received by the light absorbing layer is 200 lux. It is also shown that the photovoltaic charger is capable of generating more than 2000 μW/cm ² when the light intensity received by the light absorbing layer is 20000 lux. When the light intensity received by the light absorbing layer increases from 200 to 20000 lux, the power generated by the photovoltaic charger increases substantially linearly. Thus, the photovoltaic charger is capable of generating power under a wide range of different light conditions.

FIG. 10 is a graph showing the generated voltage (mV) for light intensities between 200 and 50000 lux according to the measured values of Table 2. FIG. As can be seen from the figure and Table 2, the solar cell was able to generate a voltage of 699 mV in an open circuit when the light intensity received by the solar cell was 200 lux. Furthermore, the photovoltaic charger is capable of generating a voltage of 943mV in an open circuit when the light intensity received by the solar cell unit is 20000 lux. As can be seen from this figure, the voltage generated is substantially linear between 3000 and 50000 lux. as From this table 2 it can be seen that the difference in the voltage generated between 200 and 20000 lux is only 244mV. Thus, the difference in voltage generated between 200 and 20000 lux is about 35%. The difference in voltage produced between 200 and 50,000 lux is only 259mV. Therefore, when the intensity of light received by the light absorbing layer varies between 200 and 50,000 lux, the solar cell unit generates a voltage that varies less than 300 mV in an open circuit. Thus, the difference in voltage generated between 200 and 50,000 lux is about 37%.

FIG. 11 is a graph showing the generated current (μA/cm ² ) for light intensities between 200 and 50000 lux according to the measured values of Table 2. FIG. As can be seen from the figure, the current increases linearly.

12 is a graph showing the generated power per area (μW/cm ² ) for light intensities between 200 and 50000 lux calculated from the measured values of voltage and current in Table 1. FIG. As can be seen from the figure, in the interval 200-20000 lux, the measured power is substantially proportional to the incoming light intensity.

Figure 13 shows an example of a tablet computer 28 that includes a rechargeable battery (not shown), a housing 29, and a photovoltaic charger integrated in the housing 29 for charging the battery 1. The photovoltaic charger 1 may be of the type 1a or 1b. The tablet computer is shown in a top view. The shape and size of the solar battery unit 2 of the photovoltaic charger are adapted to the size and shape of an upper surface of the casing 29 . For example, the size of the solar battery unit is 15×20 cm, or 20×30 cm. The top surface of the photovoltaic charger was homogeneous and there were no visible conductors on the surface of the photovoltaic charger. The solar cells of the photovoltaic charger may completely cover the top surface of the housing, or they may terminate at a distance from the edge of the housing, ie as depicted by the dashed lines in the figure. If the photovoltaic charger 1a shown in FIG. 5 is used, the first conductor 18 is arranged along one of the edges of the package and thus can be easily covered and thus is not visible to the user. . The output terminal of the boost converter 22 is connected to the rechargeable battery of the tablet computer. pool.

Figures 14 and 15a-b show an example of a headset 30 comprising a headband 32 with a photovoltaic charger 1 configured on a top surface of the headband. Figure 14 shows a top view of the headset 30, and Figures 15a-b show side views of the headset. The headset includes a rechargeable battery (not shown), and the output terminal of the boost converter 22 is connected to the battery so that the battery is charged by the photovoltaic charger. The shape and size of the solar cell unit 2 of the photovoltaic charger is adapted to the size and shape of the headband 32 of the headset. For example, the size of the solar battery unit 2 is 1.5×25 cm. The top surface of the photovoltaic charger was homogeneous and there were no visible conductors on the surface of the photovoltaic charger. The output terminal of the boost converter 22 is connected to a rechargeable battery of the headband.

FIG. 16 is a flowchart showing a method for manufacturing the photovoltaic charger. The method includes producing S1, a sheet having a single solar cell. There are several possible variations of this solar cell unit and how it is produced. Apart from the details disclosed here, the published patent applications WO2013149787 (A1 ) and WO2014184379 (A1 ), and the unpublished EP application EP17209762.8 describe how to produce the solar cell 2 . Accordingly, these three documents are hereby disclosed by reference.

The method further includes adapting S2 the shape and size of the single solar cell unit to a surface on which the single solar cell unit is to be disposed by cutting one of the sheets with the single solar cell unit into the shape and size is achieved. Any shape and size according to the limitations discussed above is possible. The single solar cell unit can thus be cut into a shape chosen by the designer of a product.

The method further includes configuring S3 the first conductor to be in electrical contact with the first conductive layer, and configuring S4 the second conductor to be in electrical contact with the second conductive layer. Alternatives for how the first and second conductors are configured have been discussed previously.

The method further comprises configuring S5 a top sheet and a bottom sheet of the package such that they surround the block of the sheet and at least partially surround the first and second conductors such that the shape and dimensions of the package are adapted to The shape and size of the single solar cell unit.

The method further includes sealing S6 edges of the top sheet and the bottom sheet to form the package. The top sheet and bottom sheet may be adhesive facing the side of the piece of the sheet so that when they are deployed over the sheet they adhere to the sheet. According to certain features, the top sheet and the bottom sheet are larger than the pieces of the sheet so that they are attached to each other at the ends. According to certain features, an adhesive may be provided on the sheets instead of them being sticky.

The method further includes disposing S3a, S4a the first and second conductors on the bottom side of the single solar cell unit. Where they should be configured has been discussed previously. Alternatively, the method comprises disposing S3b, S4a the first conductor along at least part of an edge of a top side of the solar cell unit, and disposing at least a second conductor on a bottom side of the single solar cell unit . Which side the first conductor is configured on is a choice of the system designer.

According to certain features, configuring S3 the first conductor to make electrical contact with the first conductive layer, and configuring S4 the second conductor to electrically contact the second conductive layer is comprised in configuration S5 of the top tab of the package and a bottom sheet, attaching the first conductor to the top sheet 5a or a bottom sheet 5b, and attaching the second conductor to the bottom sheet 5b. Therefore, the first and second guides, the top sheet and the bottom sheet are arranged at appropriate places at the same time as they are arranged. The at least one first conductor is then attached to the top sheet 5a or the bottom sheet 5b so that it is in electrical contact with the first conductive layer when the package is formed, and wherein the at least one second conductor is attached to the bottom sheet 5b such that it is in electrical contact with the second conductive layer when the cover is formed. The method provides a way to manufacture the device without requiring any adhesive material between the first and second conductors and the first and second conductive layers. Handling of the thin conductors is also easy when they are attached to the surface of the package. In other words, when manufacturing the photovoltaic device, the solar cell unit is set, and when the first When the first and second conductors are to be arranged on the solar cell unit, they are first arranged at corresponding positions on the top sheet 5a and the bottom sheet 5b, so that when the top sheet 5a and the bottom sheet 5b are arranged While on the solar cell unit, the first and second conductors are juxtaposed to their position on the solar cell unit.

The invention is not limited to the disclosed embodiments, but changes and modifications are possible within the scope of the following claims. For example, a porous substrate may comprise a first portion comprising a network of conductive particles housed in the pores of the porous substrate, and a second portion free of conductive particles, so as to shorten the relative The distance between the electrodes and the light absorbing layer. The photovoltaic device may include more than one second conductor disposed between the encapsulation and the solar cell unit. The photovoltaic device may also include more than one first conductor disposed between the encapsulation and the solar cell unit.

1a: Photovoltaic charger

2: Solar cell unit

3: The first connecting element

4: Second connecting element

5: Encapsulation

5a: top piece

18: First conductor

20: Second conductor

22: Boost Converter

Claims (9)

A photovoltaic charger (1; 1a; 1b) particularly adapted for charging electronic devices, comprising: a solar cell unit ( ₂ ) comprising: a working electrode comprising a porous light-absorbing Layer (10), a porous first conductive layer (12) for extracting photon-generated electrons from the light absorbing layer (10), wherein the light absorbing layer is disposed on top of the first conductive layer , a porous substrate (14) made of an insulating material and extending through the entire solar cell unit, wherein the first conductive layer (12) is formed on the porous substrate (14) On one side, the opposite electrode, which comprises a second conductive layer (16), wherein the second conductive layer is formed on the opposite side of the porous substrate (14), and a conductive medium, which is used for the Charge transmission between the opposite electrode and the light absorbing layer, encapsulation (5), which encloses the solar cell unit, a first conductor (18), which is electrically connected to the first conductive layer (12), and at least one first Two conductors (20) electrically connected to the second conductive layer (16), wherein the photovoltaic charger comprises only a single solar cell unit (2) and electrically connected to the first conductor and the second conductor (18, 20) the boost converter (22), and the boost converter is adapted to step up the voltage from the solar cell unit when stepping down the current from the solar cell unit, when by the light When the light intensity received by the absorbing layer is between 200 and 20000 lux, the solar battery unit system can generate at least 5 to 600 μW/cm ² . The photovoltaic charger as claimed in claim 1, wherein the boost converter (22) is configured to convert the voltage from the solar battery unit (2) into a voltage between 1 and 10V. The photovoltaic charger as described in claim 1, wherein the boost converter (22) is capable of converting The voltage between 0.25 and 1V is changed to a voltage exceeding 3V, and preferably exceeding 3.5V. The photovoltaic charger as claimed in claim 1, wherein when the light intensity received through the light absorbing layer is 5000 lux, the solar battery unit (2) generates at least 150 μW/cm ² . The photovoltaic charger as claimed in claim 1, wherein when the intensity of light received by the light absorbing layer varies between 200 and 50000 lux, the solar cell (2) generates a voltage that varies less than 40%. The photovoltaic charger as claimed in claim 1, wherein when the light intensity received by the light absorbing layer (10) is 200 lux, the solar battery unit (2) generates a current of at least 15 μA/cm ² , and When the light intensity received by the light absorbing layer increases from 200 to 20000 lux, the current generated by the solar cell unit increases linearly. A photovoltaic charger for powering a portable electronic device (28; 30), wherein the photovoltaic charger is the photovoltaic charger according to claim 1, wherein the shape and size of the single solar cell unit (2) are Adapt to the size and shape of the portable electronic device it powers. A photovoltaic charger for powering a portable electronic device, wherein the photovoltaic charger is a photovoltaic charger according to any one of claims 1-6, wherein the portable electronic device is a headset (30) comprising a headband (32) for reaching over the wearer's head, and the photovoltaic charger (1) arranged on the top surface of the headband. A method for manufacturing a photovoltaic charger, wherein the photovoltaic charger is a photovoltaic charger according to any one of claims 1-6, wherein the method comprises: producing a sheet (S1) with the single solar cell unit, adapting The shape and size of the single solar cell unit to a surface on which the single solar cell unit is disposed by cutting one of the sheets having the single solar cell unit into the shape and size (S2), the a first conductor configured to be in electrical contact with the first conductive layer (S3), disposing the second conductor in electrical contact with the second conductive layer (S4), disposing the top sheet and the bottom sheet of the package such that they surround the block of the sheet and at least partially surround the first conductor and the a second conductor, adapting the shape and size of the package to the shape and size of the single solar cell unit (S5), and sealing the edges of the top sheet and the bottom sheet to form the package (S6).

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