QD light emitting transistors for efficient wavelength division multiplexing

Colloidal Quantum Dot (QD) light-emitting transistors (QLETs) represent an emerging class of QD optoelectronic devices, wherein the electrical switching capability of field-effect transistors (FETs) and the light-generation capability of light-emitting diodes (LEDs) are inherently incorporated in a single device. In contrast to conventional FETs and LEDs, the planar device geometry and the versatile multifunctional nature of QLETs not only endow them with numerous technological opportunities such as wavelength division multiplexing but also render them ideal scientific scaffolds to address the fundamental physical events of charge transport and recombination dynamics. CdSe and PbS QDs have shown remarkable mobilities in FETs, and quantum efficiency in LEDs but their LET performance is poor (external quantum efficiency below<0.002%). In addition, it is essential to get away from toxic elements such as Cd and Pb, and obtain a good light emitting performance before these versatile and solution-processed LETs can be well-integrated into optical communication, display and lighting technologies. In this CDT project, there will be three objectives:

Developing QD LETs based on III-VI compound semiconductors (InP).

Investigating materials processing, device design and operation parameters for wavelength division multiplexing.

Understanding of light and electric-field induced charge transport and exciton dynamics using ultrafast spectroscopy and impedance spectroscopy.