Template method for nano-order positioning and dense packing of quantum dots for optoelectronic device application

In this paper, we present recent progress of our researches on positioning of quantum dot in the field of optoelectronics. The first research is aimed at quantum information device application. As a technology for production of quantum devices, we developed the method for positioning of a single colloidal quantum dot. Oxide lines on a Si substrate drawn by a scanning probe microscope were used as a negative etching mask with controlling their cross section in order to create a nanohole for trapping of a single quantum dot. The other research is aimed at solar cell application. It has been predicted that quantum-dot superlattice solar cell will achieve photoelectric conversion efficiency of more than 70%. After the sedimentation of the colloidal quantum dots into the pyramidal holes processed by anisotropic wet etching on a Si substrate, we observed characteristic photoluminescence from the quantum-dot sheet.