Electroluminescence and Plasmon-Assisted Directional Photoluminescence from 2D HgTe Nanoplatelets

In the visible range, 2D nanoplatelets (NPLs) have brought significant benefits compared to their 0D counterpart with an inherently anisotropic emission, a narrower photoluminescence (PL) signal, and new degrees of freedom to design heterostructures. Compared to the properties of cadmium chalcogenide NPLs in the visible, similar research is still mostly lacking in the infrared, in spite of existing synthetic paths to obtain narrow band gap semiconductors in 2D colloidal form. Here, we focus on 2D HgTe NPLs and show how their PL can be stabilized through the proper choice of surface chemistry. We then demonstrate two important steps toward bright infrared light emitting diodes (LEDs) which are (i) the coupling to a plasmonic grating to control the magnitude and spatial direction of the PL signal and (ii) the observation of electroluminescence at 1300 nm, which is near telecom wavelength.