Full Control of Solid‐State Electrolytes for Electrostatic Gating

Abstract

Ionic gating is a powerful technique to realize field‐effect transistors (FETs) enabling experiments not possible otherwise. So far, ionic gating has relied on the use of top electrolyte gates, which pose experimental constraints and make device fabrication complex. Promising results obtained recently in FETs based on solid‐state electrolytes remain plagued by spurious phenomena of unknown origin, preventing proper transistor operation, and causing limited control and reproducibility. Here, a class of solid‐state electrolytes for gating (Lithium‐ion conducting glass‐ceramics, LICGCs) is explored, the processes responsible for the spurious phenomena and irreproducible behavior are identified, and properly functioning transistors exhibiting high density ambipolar operation with gate capacitance of ≈20 − 50 µF cm−2\[20{\bm{ - }}50\;\mu F c{m^{{\bm{ - }}2}}\] (depending on the polarity of the accumulated charges) are demonstrated. Using 2D semiconducting transition‐metal dichalcogenides, the ability to implement ionic‐gate spectroscopy to determine the semiconducting bandgap, and to accumulate electron densities above 1014 cm−2 are demostrated, resulting in gate‐induced superconductivity in MoS2 multilayers. As LICGCs are implemented in a back‐gate configuration, they leave the surface of the material exposed, enabling the use of surface‐sensitive techniques (such as scanning tunneling microscopy and photoemission spectroscopy) impossible so far in ionic‐gated devices. They also allow double ionic gated devices providing independent control of charge density and electric field.

In‐Plane Heterostructured MoN/MoC Nanosheets with Enhanced Interfacial Charge Transfer for Superior Pseudocapacitive Storage

“…The specific or areal capacitance is determined from gravimetric capacitance and physical surface area. The measured double-layer capacitances of MoN/MoC-3 and MoN are 50.7 and 50.1 μF cm −2 , which are similar to the double layer capacitance for the most materials of ≈ 25-50 μF cm −2 [38]. However, the overall capacitance of MoN/MoC-3 (261.2 μF cm −2 ) in 1 m H 2 SO 4 electrolyte is much larger than that of MoN (191.0 μF cm −2 ), suggesting MoN/MoC-3 has a larger pseudocapacitance compared with MoN (Figure4g).The side-view SEM images of the MoN/MoC-3 electrodes with different thicknesses and corresponding GCD curves are depicted in Figure S13-S16 (Supporting Information).…”

“…The measured double‐layer capacitances of MoN/MoC‐3 and MoN are 50.7 and 50.1 µF cm −2 , which are similar to the double layer capacitance for the most materials of ≈ 25–50 µF cm −2 . [ 38 ] However, the overall capacitance of MoN/MoC‐3 (261.2 µF cm −2 ) in 1 m H 2 SO 4 electrolyte is much larger than that of MoN (191.0 µF cm −2 ), suggesting MoN/MoC‐3 has a larger pseudocapacitance compared with MoN (Figure 4g).…”

Defect Engineering Of Perpendicular Magnetic Anisotropy In Cobalt-Based Thin Films

“…The ability to induce phase transitions and modify material properties in a non-volatile manner is a unique advantage of ILG making it suitable for low power switching and ensures good retention properties over time. ILG has demonstrated significant potential in manipulating the magnetic properties of magnetic systems including ferromagnetic thin films [312]- [318], ferrimagnetic systems [319], [320], and antiferromagnetic and synthetic antiferromagnetic systems [321]- [325]. Extensive studies have yielded promising results for voltage control of magnetic properties using ILG in magnetic thin films.…”