OLED/QLED Device Design & Physics

Organic Light-Emitting Diode (OLED)

Organic light-emitting diode (OLED) is an LED using organic molecules (or polymers) as semiconducting materials. Now OLEDs are widely used as a main display device of cell phones, tablet PCs, and so on, owing to the merits of high brightness, high color purity, and the flexible form factor as well.

We are designing the device structure of OLEDs for achieving effient, flexible and transparent displays.

Quantum Dot LED (QLED)

A quantum dot (QD) is a nano-sized (2-10 nm) semiconducting crystal. Because the physical size of the QD is generally smaller than the exciton Bohr radius, the excitons are confined in all three spatial dimensions, resulting in very unique and superior optical properties, such as wide absorption and narrow emission bandwidth. Furthermore, the emission or absorption range can be easily controlled by changing the size of QDs during their synthesis. Owing to these great properties, QDs are considered as the most promising emitter for LEDs and display devices.

Quantum Dot LED (QLED) is an LED incorporating QDs in the emitting layer. A QLED can exhibit a narrow electroluminescence spectrum (FWHM<30 nm) in the entire visible regions. Thus, QLEDs are considered as the most promising candidate for next-generation full-color displays and lighting devices. QLEDs can be used even as the UV and IR light sources.

Thermoelectrics

Organic thermoelectric devices

A thermoelectric (TE) device is a semiconductor device that change temperature differences to electric voltage and vice versa. The phenomena is called as the thermoelectric effect. The TE devices are used for electric power generation, cooling or heating.

What we are doing is to develop the thermoelectric generators (TEGs) by using polymers and organic molecules to fabricate such TEGs in a flexible and stretchable form for the novel applications, such as IoT sensors and wearable electronic devices.