Top > Research > Liquid Crystalline Organic Semiconductors

Liquid Crystalline Organic Semiconductors

A liquid crystal is a material that exhibits liquid-like fluidity and a liquid crystal phase in which the molecules are arranged in an orderly manner like a crystal. Liquid crystal displays make use of birefringence, an optical characteristic derived from this property. On the other hand, in organic materials with semiconducting properties and liquid crystal properties, molecules spontaneously line up, making it easy to fabricate high-quality organic semiconductor thin films with orientation and order.

The molecular structure of liquid crystalline organic semiconductors is a rigid aromatic ring with a flexible hydrocarbon chain, and rod-shaped liquid crystalline organic semiconductors exhibit a layered liquid crystalline phase (smectic liquid crystalline phase).

Liquid crystalline organic semiconductors can be used in liquid crystalline phase with fluidity, but they can also be used in crystalline thin films that exhibit high mobility. This is because the liquid crystal phase is an intermediate phase between liquid and crystal, and many materials exhibit the crystalline phase at room temperature when cooled. The use of liquid crystalline phase in crystalline thin films makes it possible to fabricate flat crystalline thin films with controlled orientation and high mobility, even at high speed, by using liquid crystalline properties in the thin film fabrication process.

In our laboratory, we are studying the development of materials for liquid crystalline organic semiconductors, the evaluation of their physical and electrical properties, and the development of processes that take advantage of their liquid crystalline properties. We are also developing organic thin-film transistors, organic light-emitting diodes, organic photodiodes, and organic thin-film solar cells using this organic semiconductor material, aiming to realize flexible and lightweight displays, light-emitting devices, and photoelectric conversion devices on inexpensive plastic substrates using the printing process.

Translated with www.DeepL.com/Translator (free version)

Liquid crystalline materials have the properties of liquid-like fluidity and crystal-like ordering of molecular aggregations. Liquid crystal displays make use of birefringence, an optical characteristic derived from this property. On the other hand, in organic materials with semiconducting properties and liquid crystal properties, molecules aligned in self-organizing manner and it is easy to fabricate high-quality organic semiconductor thin films having highly ordering and orientation.
The molecular structure of liquid crystalline organic semiconductors is a rigid aromatic ring with a flexible hydrocarbon chain, and rod-like liquid crystalline organic semiconductors exhibit layered liquid crystalline phase (smectic liquid crystalline phase).
Liquid crystalline organic semiconductors can be used in liquid crystalline phase with fluidity, but they can also be used in crystalline thin films that exhibit high mobility. Liquid crystal phase is mesophase between liquid and crystal phases, so many materials exhibit the crystalline phase at room temperature when they are cooled. The use of liquid crystalline phase in crystalline thin films makes it possible to fabricate flat and uniform crystalline thin films with controlled orientation and high mobility by using liquid crystalline properties even at high speed thin film fabrication process.
In our laboratory, we are studying the development of materials for liquid crystalline organic semiconductors, the evaluation of their physical and electrical properties, and the development of processes that take advantage of their liquid crystalline properties. We are also developing organic thin-film transistors, organic light-emitting diodes, organic photodiodes, and organic thin-film solar cells using these organic semiconductor materials, aiming to realize flexible and lightweight displays, light-emitting devices, and photoelectric conversion devices on inexpensive plastic substrates using the printing process.

Research