Nanocrystal-Based Active Photonics Device through Spatial Design of Light-Matter Coupling
Tung Huu Dang, Adrien Khalili, Claire Abadie, Charlie Gréboval, Mariarosa Cavallo, Huichen Zhang, Erwan Bossavit, James K. Utterback, Erwan Dandeu, Yoann Prado, Grégory Vincent, Sandrine Ithurria, Yanko Todorov, Carlo Sirtori, Angela Vasanelli, Emmanuel Lhuillier
Abstract
The integration of photonic structures in nanocrystal (NC)-based photodetectors has been demonstrated to improve device performances. Furthermore, bias-dependent photoresponse can be observed in such devices as a result of the interplay between hopping transport and inhomogeneous electromagnetic field. Here, we investigate the main physical concepts leading to a voltage-dependent photoresponse. We first bring evidence of bias-dependent carrier mobilities in a NC array over a wide range of temperatures. Then, we fabricate an infrared sensing device using HgTe NCs, where the electrodes also play the role of a grating, inducing a spatially inhomogeneous absorption. The obtained device exhibits a significant bias-dependent photoresponse while possessing a competitive detection performance in the extended short-wave and mid-wave infrared, with detectivity reaching 7 × 1010 Jones at 80 K and a fast response time of around 70 ns. This work provides the foundation for further advancements in NC-based-active photonics devices.