WO2005041205A1

WO2005041205A1 - Rewritable memory unit made from organic materials

Info

Publication number: WO2005041205A1
Application number: PCT/EP2004/052576
Authority: WO
Inventors: Christoph Brabec; Ralph Pätzold; Carsten Tschamber
Original assignee: Siemens Aktiengesellschaft
Priority date: 2003-10-22
Filing date: 2004-10-19
Publication date: 2005-05-06
Also published as: EP1683158A1

Abstract

The invention relates to a rewritable memory unit for data. Said device (2), for the storage of data, contains a memory device (4), a write device (6) and a read device, characterised in that the write device (6) and the read device are integrally embodied such that data is received by the incidence of light and written in the memory device (4).

Description

description

Rewritable storage unit based on organic materials

The present invention relates to a rewritable storage device for data, in particular it relates to a device in which each memory cell has its own writing device, i.e. with which the data are completely written in parallel.

Conventional storage devices usually consist of three separate units: the reading unit, the writing unit and the physical data carrier. This includes common mass storage devices such as hard disks or diskettes, magneto-optical storage media, optical storage devices such as one-off (CD-Rs) or rewritable CDs (CD-Rs) and the like. In existing technology, however, it is generally not possible to equip each individual logical storage unit with an individual reading or writing unit. That Data is essentially written serially, with a write head which is guided past the physical data carrier. Usually the read / write head and the data carrier are not one unit, i.e. the actual data carrier alone does not contain any devices for writing or reading data and can be physically separated from the read / write devices.

This causes possible adjustment problems between data carriers and read / write devices. For example, the

Adjust track with magnetic read / write heads, the same applies to laser heads with CD burners or the like.

There are various guard parts of stores that contain moving parts. These deficits can be explained using the example of hard drives. On the one hand, there would be the low shock resistance, especially in operation call. Violent mechanical loads could lead to a so-called "head crash", that is to say the read / write head falls onto the surface of the magnetic disk. This would inevitably result in the destruction of the hard disk during operation and can damage the read / write head or the surface of the data carrier even when the magnetic disks are stationary. The necessary movement of the heads consumes energy and causes an access time (latency). The same applies to the necessary rotation of the magnetic disks. In general, mechanical movement can produce unwanted noise and wear.

It is common to almost all existing storage devices that the writing or reading out of the data is essentially serial. This means that the writing or reading process takes a lot of time. The necessary positioning of the read / write head in relation to the data carrier can only take place in finite time, this causes the occurrence of a noticeable access time. A completely parallel writing of a storage device would be desirable to avoid the disadvantages described.

A system which contains read / write device and data carrier in one could be protected against problems of adapting the data carrier and read / write device. The

The properties of the read / write device could be optimally matched to the physical data carrier.

Conventional memories such as RAM memory modules can in principle be designed in such a way that data can be written in parallel. The main disadvantage of these widespread memories is that they rely on a constant energy supply in order to preserve their memory content Their content must be refreshed at intervals. This causes constant energy consumption during operation, even without writing operations occurring. In addition, the memory content remains without Energy supply not received, so it is volatile storage.

The object of the present invention is to provide a data storage device which has various advantages. It is made up of cheap, easy-to-manufacture and energy-saving components. Data can be written to the device in parallel, i.e. each cell of the memory device can be written to simultaneously.

The influence of organic electronics has multiplied in recent years. It enables the production of lighter, space-saving and cheaper electronic components based on organic materials such as "small molecules" and polymers. Another fundamental advantage is the ability to apply organic components to flexible substrates. The high point of this development to date has been organic light-emitting diodes (OLEDs) and organic displays as well as organic solar cells and photo detectors. The latter basically consist of thin organic films, which are stored as electrodes between two metal layers. If light falls through the transparent electrode, free charge carriers are created in the organic layer. A voltage can now be tapped between the electrodes via a resistor.

Bistable organic components, "Organic Bistable Devices" (OBDs), are components made of several alternating layers of metal and organic molecules, the conductivity of which can be switched back and forth between two discrete states by means of an applied voltage. In the basic state with no voltage applied, the resistance of the OBDs is considerable. However, if the contact voltage exceeds a certain value, the conductivity increases by four to five orders of magnitude. This state continues even after the voltage is switched off. However, the process is reversible. By briefly applying a low counter voltage, the component can be switched back to the basic state.

According to one aspect of the invention, a device is provided which is intended for storing data. The device contains a storage device. Furthermore, it contains a writing device which is designed to be integral with a reading device in such a way that the device can receive data through the incidence of light and write it into the storage device.

It is preferred that the memory device contains at least one memory component, which is a bistable component.

It is preferred that the writing device contains at least one writing component, which is a photodetector.

It is preferred that the reading device contains at least one reading component, which is a photodetector. This makes it possible to receive light and convert it into a proportional electrical signal in an easily and inexpensively available component.

It is preferred that a writing component of the

Writing device and a reading component of the reading device are integrally designed as a writing / reading component.

It is preferred that each memory component of the memory device is assigned a read / write component common to the write device and the read device.

It is preferred that the memory device is rewritable. This means that any data can be deleted or overwritten with new data. It is preferred that the memory device is a non-volatile memory. This means that the saved data is retained even after the write process without any additional energy supply.

It is preferred that the memory component is a bistable component that consists at least partially of organic material.

It is preferred that the writing component is a photodetector that is at least partially made of organic material.

It is preferred that the reading component is a photodetector that consists at least partially of organic material.

It is preferred that the writing device is electrically connected to the storage device.

It is preferred that the storage device that

Writing device and the reading device are mounted on a common carrier.

Further advantages, features and possible uses of the present invention result from the following description of a preferred exemplary embodiment in conjunction with the drawing.

FIG. 1 shows an embodiment of the device according to the invention.

Figure 2 shows another of the device according to the invention.

A storage device 4, a writing device 6 and a reading device are shown in the figures.

Memory components 8 of the memory device 4 are arranged in a layer that extends over a surface and in the storage device 4 in its entirety. Likewise, writing / reading components 18 of the writing device 6 and reading device are arranged in a layer which spreads over a surface and forms an integral combination of writing device 6 and reading device in its entirety. The two layers 4 are produced directly adjacent to one another or on top of one another. For reasons of clarity, the two layers are shown separated by a larger distance. There are conductive connections between a cell corresponding to a memory component 8 of the memory device 4 and a cell corresponding to a read / write component 18 of the write device 6 and read device, which enable the interaction of the memory components 8 with the read / write components 18. However, these are not shown here in order to be able to present the layers in a more clearly arranged manner.

The data is sent to device 2 using light. Each reading component of the reading device can collect light and convert it into a corresponding voltage. The step of receiving light corresponds to the reading function of the reading device. The write function is to control a memory component 8 of the memory device 4 by means of the voltage generated by the write unit 6 and to switch it to the desired of the two stable states. One of the states corresponds to binary "0" and the other to binary "1". A resistance value of a memory component 8 is then assigned to each possible value “0” or “1”. The two resistors, which correspond to the two possible states of a memory component 8, differ by approximately 4-5 orders of magnitude. Data that has been written into the memory device 2 in the manner described by means of light can now be read out electrically by applying a voltage to the memory components 8 of the memory device 4. It is only necessary to ensure that the polarity of the applied device Voltages must be the same direction as the writing voltage, and the level of the voltage must be clear must be below the switching voltage. Otherwise, the integrity of the memory content would not be guaranteed, since reading out with such a voltage can cause a switchover from one state to another. This is because the switching over of the individual cells can take place in the excited state by a low counter-voltage, or, if the cell is in the ground state, by a sufficiently high voltage. Data can be read out using a passive matrix. Since only resistances have to be measured, only low currents are required, and the reading out of the device 2 can thus be designed to save energy.

The great functional advantage of the described device is that each memory component 8 of the memory device 4 has its own write unit of the write device 6. This means that data can be written into the memory device 4 completely in parallel. Apart from an offset, which can result from the reaction time of the write components, the read components and the memory components 8, the speed of the write process is practically independent of the amount of data to be written. That Write operations can be reduced to a minimum. This is a great advantage compared to conventional, serial write processes with widespread data storage. With such memories, the time for writes scales essentially linearly with the amount of data to be written.

Furthermore, the storage device described has the advantage of being written, ie optically, by means of light. You could also say that it is able to convert data from an optical form to an electrical form. This results in a wide range of possible uses and advantages. For example, the device can be used in applications in which data must be transmitted between two systems which are to be electrically separated from one another. Or it can be used in situations where it is necessary to store information in an optical form available. In contrast to electrical data signals, optical data signals do not rely on a transmitting conductor, which results in a number of possible advantages that are certain to be apparent to experts.

FIG. 2 shows the layer structure of a device according to the invention from the side. It is extended in a direction perpendicular to the drawing surface. The carrier material of the carrier 12 is located at the lower position, above which the memory components 8 are then applied. The top layer is formed by the read / write components 18, which are connected directly to the storage components 8 located underneath. The data are written in by means of light beams L which fall on the read / write components 18 from above. The layer of the read / write component 18 in its entirety forms the integral write device 6 and the read device.

Organic components (OBDs, OLEDs, photodiodes and the like) are just as inexpensive to manufacture as they are lightweight, energy-saving and extremely compact. Combining the bistable organic components described above with the organic photodetectors also mentioned, novel memory modules can be produced with excellent properties. These memory cells can be used in optically relevant applications in which light has to be converted directly into information. They can also be used in electronic data processing. They offer the possibility of producing the described memory device 2 very easily using existing techniques (structuring, etc.). By mounting the necessary memory components 8 and the read / write components 18 on a common carrier 12, large arrangements of a device 2 according to the invention can also be produced in a simple and very inexpensive process. The steps for structuring the memory components 8 and the write / read components 18 can be identical in part, the manufac The storage device 2 is essentially limited to the application of different layers of metal and organic material to the carrier 12. The necessary connections between the storage device 4 and the writing device 6 can be realized in the layer structure in a very simple manner.

The device 2 is made up entirely of semiconductor components, i.e. it has no moving parts. This avoids the disadvantages described above which arise when storing with moving parts. The device 2 therefore also operates with little noise. The device 2 is also characterized by low energy consumption, which is based on the use of organic semiconductors.

Since the memory cells are bistable organic components, the memory content is retained after the write process without an energy supply. It is a non-volatile memory, in contrast to conventional RAM memory modules, for example.

The device according to the invention has no moving parts. It can be used to convert light into information. It is largely insensitive to mechanical shock loads since it contains no moving parts.

It is rewritable. The device is a non-volatile memory.

Claims

claims

1. Device (2) for storing data, containing a storage device (4), a writing device (6) and a reading device, characterized in that the writing device (6) and the reading device are integrally formed such that they contain data by the idea received by light and written into the memory device (4).

2. Device according to claim 1, wherein the memory device (4) contains at least one memory component (8), characterized in that the memory component (8) is a bistable component.

3. Device according to one of the preceding claims, wherein the writing device (6) contains a writing component, characterized in that the writing component is a photodetector (18). , Device according to one of the preceding claims, wherein the reading device contains a reading component, characterized in that the reading component is a photodetector (18).

5. Device according to one of the preceding claims, wherein in each case a writing component () of the writing device (6) and a reading component of the reading device are designed integrally as a writing / reading component (18).

6. Device according to one of the preceding claims, wherein each memory component (8) of the memory device (4) is assigned a write / read component (18) common to the write device (6) and the read device.

7. Device according to one of the preceding claims, characterized in that the memory device (4) is rewritable.

8. Device according to one of the preceding claims, wherein the memory device (4) is a non-volatile memory.

9. Device according to one of the preceding claims, wherein the storage component (8) is a bistable component which consists at least partially of organic material.

10. The device according to claim 3, wherein the writing component () is a photodetector which consists at least partially of organic material.

11. The device according to claim 4, wherein the reading component is a photodetector which consists at least partially of organic material.

12. Device according to one of the preceding claims, wherein the writing device (6) is electrically connected to the storage device (4).

13. Device according to one of the preceding claims, characterized in that the storage device (4), the writing device (6) and the reading device are mounted on a common carrier (12).