Controlling the charge carrier density is pivotal in nanoelectronic devices. To date, two main approaches have been engineered using either dielectric (SiO2, AL203 ..) or electrolyte (ion gel, polymer electrolyte..). Dielectric gating allows fast bias sweeping over a broad range of temperatures but requires a large operating bias. Electrolytes, thanks to large capacitances, lead to the significant reduction of operating bias but are limited to slow and quasi-room-temperature operation.
In a collaborating work lead by Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS) and Institut des Nanosciences de Paris (INSP), researchers demonstrated a novel technology of phototransistor using Ionic Glasses as gating medium. The Ionic Glass gate allows achieving very high doping levels exceeding those of dielectric, while preserving operability at lower temperature and providing top and bottom optical accesses not accessible with electrolyte technology.
The researchers demonstrate that Ionic Glass is optimal technology to build infra-red nanocrystal-based phototransistors. They unveil the unique property of this method to enable the unprecedented tunability of both magnitude and dynamics of the photocurrent, signal-to-noise ratio improved by a factor of 100, and boosted time photoresponse.
The performances of these photodetectors demonstrate the potential of Ionic Glass technology to explore novel photoconduction processes and alternative architectures of devices. The approach is generic, and can be easily extended to any photoconducting nanomaterials, including 2D material, organic thin film, and hybrid materials.
