Emissive ZnO-graphene quantum dots for white-light-emitting diodes

Tufan GhoshDepartment of Chemistry

Indian Institute of Technology Madras

Won Kook Choi et al., Nature Nanotecnol., 2012, 7, 465-471

Won Kook Choi et al., Nature Nanotecnol., 2012, 7, 465-471

Introduction Graphene has diverse applications in the field of physics, chemistry and material science

ZnO has been a promising material in development of exciton-based optoelectronic devices such as LEDs and photovoltaic cells

Quantum dots, because of the quantum confinement effect, has potential application in nanoscale devices such as next-generation electronic and optoelectronic devices (including LEDs and solar cells)

Won Kook Choi et al., Nature Nanotecnol., 2012, 7, 465-471

Chemical synthesis process for the ZnO-graphene quasi-quantum dots

Won Kook Choi et al., Nature Nanotecnol., 2012, 7, 465-471

Structural characterization of ZnO-graphene quantum dots

Won Kook Choi et al., Nature Nanotecnol., 2012, 7, 465-471

Optical characterization of ZnO-graphene quantum dots

Won Kook Choi et al., Nature Nanotecnol., 2012, 7, 465-471

Modelling of DOS

Won Kook Choi et al., Nature Nanotecnol., 2012, 7, 465-471

Modelling of DOS

Won Kook Choi et al., Nature Nanotecnol., 2012, 7, 465-471

Modelling of DOS

Won Kook Choi et al., Nature Nanotecnol., 2012, 7, 465-471

Characterization of ZnO-graphene quantum-dot LEDs

Won Kook Choi et al., Nature Nanotecnol., 2012, 7, 465-471

Summary and conclusion A novel, simple and facile technique have been developed for the synthesis of ZnO-graphene quasi-core-shell QDs

Blue emissions (406 nm and 432 nm) were observed in ZnO-graphene quantum dots which are absent in pure ZnO quantum dots

DFT calculations shows that these new peaks are due to the splitting of the LUMO of graphene in three orbitals with distinct energy levels

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