Heterojunction properties between quantum dots and low-dimensional nanostructures for enhanced optoelectronic applications

Abstract

Quantum dot (QD) is a nano-scale semiconductor, which has quantum confinement effect. Representative character of the QD is that when size of the QD is below Bohr radius, bandgap of the QD is changed by the size. Using this advantage, the QD has been vigorously studied for opto\electronic applications, such as solar cells, lightings, light-emitting diodes, photocatalysts, photodetectors and so on. In this dissertation, I enhanced optoelectrical efficiency of the QD applications using heterojunction properties between the QD and low dimensional nanomaterials, and suggested more applicability of the QD. Current efficiency of QD-based light emitting diodes was enhanced through heterojunction between 0-D ZnS nanoparticles and the QD. In addition, adapting heterojunction between carbon nanofiber and the QD, photocatalytic hydrogen production efficiency was enhanced. The former took advantage of a heterojunction property of suppressing non-radiative energy transfer between QDs, and the latter used a heterojunction property of splitting electron-hole pairs in the QD.