Electrically-Driven Polarized Nano-Light Sources Based on Suspended Graphene Nanoscrolls.

Low-dimensional nanomaterials hold great promise for on-chip light-emitting applications and are expected to profoundly influence the evolution of next-generation photonic chips. Currently, microlasers and light-emitting diodes represent the predominant on-chip integrated light sources. Exploring how to employ low-dimensional materials to realize more miniaturized and controllable light sources remains a key research focus over the past decade. In this work, we demonstrate a high-efficiency nanolight source (NLS) based on graphene nanoscrolls (GNSs), with its emission modulated via an external electric field and device structural design. The GNS NLS features a widely tunable emission spectrum, covering wavelengths from the infrared to the visible range. Besides, we investigated the super-Planckian radiation effect in GNSs, which arises from enhanced absorption in the low-dimensional nanostructure. The theoretical calculations reveal that the absorption coefficient of GNSs in the normal direction is larger than 1, thereby indicating their strong radiative emission according to Kirchhoff's Law of thermal radiation. Furthermore, the emission from GNSs can exhibit fast switching behavior (response time ∼ 75 ms), with the degree of polarization reaching 20% in the visible light range. This work provides important support for the study of the emission characteristics of GNSs and holds profound significance for promoting the development of on-chip integrated NLS technology.