Organic ferroelectric non-volatile memories and opto-electronics

Promotie: dhr. K. Asadi, 13.15 uur, Academiegebouw, Broerstraat 5, Groningen

Proefschrift: Organic ferroelectric non-volatile memories and opto-electronics

Promotor(s): prof.dr. P.W.M. Blom, prof.dr. D.M. de Leeuw

Faculteit: Wiskunde en Natuurwetenschappen

Contact: Kamal Asadi, tel. 050-363 5211, e-mail: k.asadi@rug.nl

Organic ferroelectric non-volatile memories and opto-electronics

The ability to store information is essential to many of the envisioned applications of organic electronics. To store information, memory devices make use of a physical property that displays hysteresis in response to an external stimulus. Measuring the actual state of the hysteretic property retrieves the stored information. Volatile memories, memories based on a technology that the stored information needs to be restored at regular time intervals, are inappropriate for many applications like radio frequency identification (RFID) tags, where the stored information needs to be stored in absence of a power source. A nonvolatile memory, a storage system where the information is preserved after removing the external power, is the memory of choice for such applications.

This thesis addressed the development of a solution-processed organic nonvolatile memory device, to be use in ultra-low-cost applications. Applications that one can conceive for such plastic memory devices are low-cost data storage and large area displays. For data storage applications, in terms of production costs, the plastic memory would have to compete with Flash memory technology (currently a multibillion euro market). Another major application is integrated memory to be used in RFID tags intended to replace bar codes. In order to compete with bar codes, it is estimated that the purchase price of the tags must come down to a few cents or less. This is unattainable with traditional silicon technology, but it may be achievable by using organic. For display applications on the other hand, the polymer memory is employed as an electrical switch to address pixels. Here it has to compete with the well-established thin-film transistor technology used for this propose.

There are several scenarios towards development of an organic nonvolatile and rewritable memory device. Some of these efforts are focused on metal-organic semiconductor-metal junctions, charge trapping effects in field-effect transistors, and electromechanical switches. This thesis aimed to capture the developments for one particular approach, i.e. those based on ferroelectricity, reviewed the status of the field and demonstrated viability of a novel approach toward non-volatile ferroelectric memories for (opto)-electronics applications.