Affiliation: | 1. IPCMS‐CMRS UMR 7504, Université de Strasbourg, 23 Rue du Loess, 67034 Strasbourg, France;2. CNRS, Institut des NanoSciences de Paris, INSP, Sorbonne Université, F‐75005 Paris, France;3. HORIBA Scientific, HORIBA France S.A.S, Avenue de la Vauve, Passage Jobin Yvon, 91120 Palaiseau, France;4. Centre de Nanosciences et de Nanotechnologies, CNRS, Université Paris‐Sud, Université Paris‐Saclay, C2N–Marcoussis, 91460 Marcoussis, France;5. CNRS, Institut des NanoSciences de Paris, INSP, Sorbonne Université, F‐75005 Paris, FranceE‐mail: ,;6. https://orcid.org/0000-0001-5625-9263;7. IPCMS‐CMRS UMR 7504, Université de Strasbourg, 23 Rue du Loess, 67034 Strasbourg, FranceE‐mail: , |
Abstract: | Modulating the carrier density of 2D materials is pivotal to tailor their electrical properties, with novel physical phenomena expected to occur at a higher doping level. Here, the use of ionic glass as a high capacitance gate is explored to develop a 2D material–based phototransistor operated with a higher carrier concentration up to 5 × 1013 cm?2, using MoSe2 over LaF3 as an archetypal system. Ion glass gating reveals to be a powerful technique combining the high carrier density of electrolyte gating methods while enabling direct optical addressability impeded with usual electrolyte technology. The phototransistor demonstrates ION/IOFF ratio exceeding five decades and photoresponse times down to 200 µs, up to two decades faster than MoSe2 phototransistors reported so far. Careful phototransport analysis reveals that ionic glass gating of 2D materials allows tuning the nature of the carrier recombination processes, while annihilating the traps' contribution in the electron injection regime. This remarkable property results in a photoresponse that can be modulated electrostatically by more than two orders of magnitude, while at the same time increasing the gain bandwidth product. This study demonstrates the potential of ionic glass gating to explore novel photoconduction processes and alternative architectures of devices. |