Sensors based on 2D rGO/2D MoS2 van der Waals hybrid composites exhibited high sensitivity, extreme selectivity, fast response/recovery, and good reliability to humidity detection.

A new type of wearable electronic device, called a textile memory, is reported. This is created by combining the unique properties of Al‐coated threads with a native layer of Al2O3 as a resistance switching layer, and carbon fiber as the counter‐electrode, which induces a fluent redox reaction at the interface under a small electrical bias (typically 2–3 V). These two materials can be embroidered into an existing cloth or woven into a novel cloth. The electrical resistance of the contacts is repeatedly switched by the bias polarity, as observed in the recently highlighted resistance switching memory. The devices with different structure from the solid metal‐insulator‐metal devices show reliable resistance switching behaviors in textile form by single stitch and in array as well that would render this new type of material system applicable to a broad range of emerging wearable devices. Such behavior cannot be achieved in other material choices, revealing the uniqueness of this material system.

Reduced graphene oxide (rGO) possesses a similar electronic structure to graphene but can be synthesized on a larger scale. Hence, rGO is considered as an attractive alternative to graphene. Here we report the carrier transport properties of thermally reduced graphene oxide (TrGO) as a function of reduction temperature. The transfer curve of a field effect transistor fabricated with TrGO exhibited ambipolar properties, and the charge neutrality point of TrGO was shifted from negative to positive as the reduction temperature increased. Furthermore, as revealed in Arrhenius plots of the carrier densities and carrier mobilities, TrGO behaved as a metallic conductor at all reduction temperatures. To investigate the effect of reduction temperature on the thermoelectric properties of TrGO, the Seebeck coefficients of the fabricated TrGOs were calculated from the transfer curve using Mott's equation for metallic materials. All samples showed ambipolar carrier transport. At V g = 0 V, the Seebeck coefficient switched sign from negative to positive as the reduction temperature became higher, indicating that electron and hole carrier transport dominates at higher and lower reduction temperature, respectively. The calculated Seebeck coefficients at zero gate bias were compared with the measured coefficients in TrGO bulk films. The thermoelectric properties of the measured and calculated coefficients showed similar trends with increasing reduction temperature, and the charged carrier transport (i.e., the energy states) of TrGO can be tuned by varying the reduction temperature without doping with impurities.