Tunable and white light photoluminescence from ZnO on porous Si with the addition of carbon quantum dots.

In this work we demonstrate a two-pixel solid-state photoluminescent device able to emit white light covering the entire visible spectrum from 380nm up to 800nm. The device is based on a combination of porous Si, hydrothermally grown ZnO and carbon quantum dots, in a two-pixel formation, with porous Si and ZnO acting independently while the carbon quantum dots are deposited on top of the entire device. All processing is done using standard Si processing techniques. Moreover, the device design allows for tunability of the emitted spectrum simply by choosing the desired combination of the materials. Overall, the demonstrated device is low cost, environmentally safe and biocompatible. .