Research Fields

Printed flexible electronic devices

Organic semiconductors have great potential for future electronic applications owing to their inherent flexibility, low cost, light weight and ability to easily cover large areas. There are a few solution-based techniques such as spin-coating and inkjet printing that meet the above criteria.

Transparent conductive films (TCFs)

Transparent conductive films are indispensable components for various optoelectronic devices. Recently, the development of flexible TCFs has received attention for applications in flexible and wearable electronics. TCFs can be deposited by solution process and it has the advantage of low cost and can be applied to a large-scale devices using a solution process.

Solution processed metal oxide transistors

Metal-oxide semiconductors have emerged as potential replacements for organic and silicon materials in thin-film electronics. Moreover their solution processability and optical transparency have opened new horizons for low-cost printable and transparent electronics on plastic substrates.

High performance organic single crystal field-effect transistors

Organic single crystal field-effect transistors (SC-FETs) have much higher mobility than organic thin-film transistors (OTFTs) because grain boundaries in thin film can act as obstacles, which disturb the movement of charge carriers. We expected that the study of SC-FETs would contribute to fundamental study of small-molecule semiconductor with high mobility.

Zone casting organic semiconductors

Many researchers have been focused on organic semiconductors over the past decade because these devices have many advantages such as low-cost, large-area deposition, and flexibility. Soluble organic small-molecule materials with high crystallinity can be deposited by zone casting technique. The high mobility and easy fabrication of organic small-molecule materials make it very attractive in terms of organic thin-film transistors.

Ambipolar transistors

Organic materials have gained interest for use in flexible electronic devices. Ambipolar materials have the unique property that they can operate as p- or n-type organic transistors with one active layer. To investigate the charge injection characteristics of ambipolar transistors, these devices are processed via various types of self-assembled monolayer treatments and annealing. To extract contact resistance of ambipolar transistors, we used simultaneous extraction model and their results were compared to gate four point probe measurement.

Electronic textile

A new type of wearable electronic device, called a textile memory, is reported. This is created by combining the unique properties of Al-coated threads with a native layer of Al2O3 as a esistance switching layer, and carbon fiber as the counter-electrode, which induces a fluent redox reaction at the interface under a small electrical bias (typically 2-3 V).

Flexible Piezoelectric energy harvester

Recently Energy harvester have attention as a smart module such as drive way and sport wear and so on. We can obtain electrical energy through the flexible piezoelectric energy harvester and use for measure system. Flexible piezoelectric energy harvester uses PVDF film which is a polymer material that hydrogen and fluorine are arranged in a straight line on carbon. When pressure is applied to the material, the size of the dipole is changed and it makes the mechanical energy generate electrical energy.