Community Research and Development Information Service - CORDIS


UNIQDS Report Summary

Project ID: 340538
Funded under: FP7-IDEAS-ERC
Country: United Kingdom

Mid-Term Report Summary - UNIQDS (Universal Framework for Charge Transport in Quantum Dot Systems)

We reported comprehensive and fundamental understanding of underlying physics accounting for energy/charge transport dynamics in various QD systems to provide basic knowledge and platform of creating new structure and concept for various electronic and optoelectronic device applications, such as charge generation model for LEDs or charge separation model for solar cells. We have focused on developing charge transport dynamics with physical properties using energy band alignment and energy level modulation through both simulation and experiment. The charge transport behaviour depending on inside-QD structures in terms of QD shape, size, energy level modulation, and bandgap engineering of QD and its surface-bound layer were investigated. The relationship from QD-QD, QD/interface/matrix to QD-layer was also studied through the engineering inorganic and organic small molecule ligands and their inner surface which are crucial factors to define the charge transport behaviour in QQ system and to obtain high performance optoelectric and electric devices such as LEDs, solar cells, TFTs and various type of photo sensors. We also successfully set up the modelling framework based on the kinetic Monte Carlo or time dependent random walk which is used for charge transport model which provides an important research basis on charge transport dynamic studies to many various systems, such as ordered/disordered 1D QD chain/2D/3D system. For the practical usage of QD materials, we also designed and developed high quality Cd-free QDs, lead (Pb) and zinc (Zn) chalcogenide QDs which are well acknowledged to be the most promising QD candidates in terms of their applicability and sustainability. We reported the novel synthesis protocol of the high quality QDs and the modification of their electronic structures based on the framework described in the proposal. The produced Cd-free QD materials covers from UV to IR and their electronic structures such as band gap and Fermi level were tailored by size, stoichiometry control and/or surface ligand modification. The enhancement of charge transport in the QD devices were also achieved by the design of favourable band alignment structure with various size of QDs. Through the multi junction structured QD solar cell structure, we successfully demonstrate a CJQDSC can generate 10.05% PCE performance, which are higher than any of its constituent QDSC, particular with an outstanding high Jsc (33mA/cm2) and high Rsh (305Ωcm2). We explored monolayer MoS2 crystal for unique optical memory as well as interaction of QD-MoS2 for new photodetectors. Lastly, we developed monolayer level process techniques for fabricating devices using unique nano transfer printing technology.

Reported by

United Kingdom
Follow us on: RSS Facebook Twitter YouTube Managed by the EU Publications Office Top