Selective area growth and characterization of InGaN nanocolumns for phosphor-free white light emission

This work reports on the morphology and light emission characteristics of ordered InGaN nanocolumns grown by plasma-assisted molecular beam epitaxy. Within the growth temperature range of 750 to 650 °C, the In incorporation can be modified either by the growth temperature, the In/Ga ratio, or the III/V ratio, following different mechanisms. Control of these factors allows the optimization of the InGaN nanocolumns light emission wavelength and line-shape. Furthermore, yellow-white emission is obtained at room temperature from nanostructures with a composition-graded active InGaN region obtained by temperature gradients during growth.