Hydrogen Sensing Performance of ZnO Schottky Diodes in Humid Ambient Conditions with PMMA Membrane Layer Enhanced hydrogen sensing performance of Pt Schottky diodes on ZnO single crystal wafers in humid ambient conditions is reported using a polymethylmethacrylate (PMMA) membrane layer. ZnO diode sensors showed little change in forward current when switching to wet ambient H2 conditions with 100% relative humidity. This sensitivity drop in the presence of water vapor can be attributed to surface coverage of hydroxyl groups on the Pt surface in humid ambient conditions. The hydrogen sensitivity of PMMAcoated diode sensors recovered up to 805% in wet H2 ambient conditions at room temperature. The PMMA layer can selectively filter water vapor and allow H2 molecules to pass through the membrane layer. It is clear that the PMMA layer can effectively serve as a moisture barrier because of low water vapor permeability and its hydrophobicity. In both dry and wet conditions, ZnO diodes exhibited relatively fast and stable onoff switching in each cycle with good repeatability.

Mos2 transistor gated by PMMAbased electrolyte for sub1 V operation The fabrication of highperformance MoS 2  transistor with a reliable gate dielectric layer remains an obstacle due to the lack of dangling bonds for dielectric deposition. Here, we demonstrate the employment of PMMAbased electrolyte film as the gate dielectric for Mos2 transistors. The electrolyte can be utilized to form high quality and uniform thin film by spincoating method at room temperature. Based on this PMMAbased electrolyte film, topgated Mos2 field effect transistors (FETs) are fabricated and exhibit exceptional device performance. The ultrahigh capacitance of the electrolyte, resulting from the formation of an electric double layer (EDL), yields a current onoff ratio about 105 and a steep subthreshold swing (90 mVdec) within a low supply voltage (1 V). Furthermore, we investigate the dynamic response of a Mos2 inverter with a switching speed over 100 Hz. This result provides the possibility for realizing low power logic circuit and nanoelectronics.