Photonic crystal-assisted light extraction from a colloidal quantum dot/GaN hybrid structure

We present a study of the light extraction from CdSe/ZnS core/shell colloidal quantum dot thin films deposited on quantum well InGaN/GaN photonic crystal structures. The two-dimensional photonic crystal defined by nanoimprint lithography is used to efficiently extract the guided light modes originating from both the quantum dot thin films and the InGaN quantum wells. Far-field photoluminescence spectra are used to measure the extraction enhancement factor of the quantum dot emission ( x 1.4). Microphotoluminescence measurements show that the guided mode effective extraction lengths range between 70 and 180 mu m, depending on the wavelength of light.