Visible and Infrared Nanocrystal-Based Light Modulator with CMOS Compatible Bias Operation

Abstract

Nanocrystals are now established light sources, and as synthesis and device integration have gained maturity, new functionalities can now be considered. So far, the emitted light from a nanocrystal population remains mostly driven by the structural properties (composition, size, and shape) of the particle, and only limited postsynthesis tunability has been demonstrated. Here, we explore the design of light amplitude modulators using a nanocrystal-based light-emitting diode operated under reverse bias. We demonstrate strong photoluminescence modulations for devices operating in the visible and near-telecom wavelengths using low bias operations (<3 V) compatible with conventional electronics. For a visible device based on 2D nanoplatelets, we demonstrate that the photoluminescence quenching is driven by the field-induced change of nonradiative decay rate and that the field is less involved than the particle charging. This work demonstrates that a simple diode stack can combine several functionalities (light-emitting diode, detector, and light modulator) simply by selecting the driving bias.