In Situ Mapping of the Vectorial Electric Field within a Nanocrystal-Based Focal Plane Array Using Photoemission Microscopy

Abstract

Within a few years, nanocrystal-based infrared devices have achieved significant progress and advancements, including high-quality imaging systems. This raises the need to develop tools that can probe the active material of the device in situ and in operando to gain a deeper understanding of their operation beyond the overall response of the device. Here, we investigate a short-wave infrared imager based on HgTe nanocrystals with photoconductive operation, which now proposes imaging at wavelengths beyond the traditional InGaAs technology. We demonstrate that we can use photoemission microscopy to probe the energy landscape of this imaging array. Finally, we further use the high spatial resolution of the method to get access to the vectorial distribution of the electric field.

Infrared Imaging Using Thermally Stable HgTe/CdS Nanocrystals

“…PbS NC-based cameras have been demonstrated with extremely small pixel pitch − (i.e., <2 μm, whereas best strategies based on InGaAs still present a pixel pitch larger than 5 μm). Moreover, HgTe focal plane array (FPA) operation , from near- to mid-IR , has been achieved with all possible operation modes: photoconductive, ,− photovoltaic, and even phototransistor …”