Researchers in the US and Saudi Arabia are the first to have observed negative transconductance (NTC) inside multilayer molybdenum-disulphide (MoS2) transistors with optimized graphene/metal hybrid contacts. The NTC behaviour comes about thanks to competition between inter-layer charge transport and charge transport through a vertical potential barrier in the MoS2. This unique effect could be exploited for making frequency doublers and phase-shift keying circuits with only one multilayer transistor – something that would greatly simplify circuit design compared to conventional technology, says the team.
Electrodes containing porous graphene and a niobia composite could help improve electrochemical energy storage in batteries. This is the new finding from researchers at the University of California at Los Angeles who say that the nanopores in the carbon material facilitate charge transport in a battery. By fine tuning the size of these pores, they can not only optimize this charge transport but also increase the amount of active material in the device, which is an important step forward towards practical applications.