Focal plane array based on HgTe nanocrystals with photovoltaic operation in the short-wave infrared
Rodolphe Alchaar, Adrien Khalili, Nicolas Ledos, Tung Huu Dang, Maxime Lebreton, Mariarosa Cavallo, Erwan Bossavit, Huichen Zhang, Yoann Prado, Xavier Lafosse, Victor Parahyba, Pierre Potet, David Darson, Emmanuel Lhuillier
Abstract
Thanks to their remarkable spectral tunability across the entire infrared range, HgTe nanocrystals present a unique platform for designing infrared optoelectronic devices. While in recent years most of the significant advances in this domain have been made on devices at the single-pixel level, there is a growing trend toward exploring the potential of this material for imaging applications. However, until recently, focal plane arrays based on HgTe colloidal nanocrystals have been limited to the photoconductive mode, which is inherently associated with a large dark current. In this work, we demonstrate a diode stack compatible with a readout integrated circuit whose back-end processing has been optimized to ensure compatibility with a complete diode stack deposition. The diode design is also optimized to generate a Fabry–Pérot cavity in which 50% of the light is effectively absorbed at the band edge. Finally, taking benefit from the full video graphics array format, high-resolution images are taken.