Volume 5 Issue 1, January 2022

Autonomous vehicles are not a panacea for the issues that currently plague transportation systems. Smart policies — which are flexible enough to deal with emerging technologies — are required to help cities and states realize the benefits of these vehicles.

Electric vehicles could help reduce greenhouse gas emissions and deliver a sustainable transport system. But the full life cycle of electric vehicles needs to be considered in order to avoid creating resource issues while trying to achieve the necessary climate goals.

Technical and economic developments in battery and fast-charging technologies could soon make fuel cell electric vehicles, which run on hydrogen, superfluous in road transport.

Cities are central to increasing the uptake of electric vehicles. A range of situational and contextual factors will influence this process, and cities need to use a variety of mechanisms — including policies and incentives — to drive the necessary change.

Solid-state electronic components that control and convert electrical power are key to the energy management and lifetime of electrified transport.

By incorporating oxygen into the chemical vapour deposition growth of molybdenum disulfide, sulfur vacancies can be passivated and contact resistances lowered.

Field-effect transistors based on heterojunctions of hydrogen-terminated diamond and hexagonal boron nitride can offer surface carrier mobilities as high as 680 cm² V^–1 s^–1.

A molybdenum disulfide/tungsten diselenide van der Waals heterostructure can exhibit a room-temperature valley Hall effect with electrically tunable magnitude and polarity, which can be used to create a bipolar valleytronic transistor.

Sulfur vacancies in monolayer molybdenum disulfide can be passivated using an oxygen-incorporated chemical vapour deposition technique, which results in less n-type doping, enhanced photoluminescence and decreased contact resistance compared with growth without oxygen.

Wide-bandgap transistors with room-temperature hole mobility of 680 cm² V⁻¹ s⁻¹ can be created without surface doping using hydrogen-terminated diamond/hexagonal boron nitride heterostructures.

Solid-state tandem structures that use protons as the diffusing species can be used to create electrochromic devices that exhibit high contrast ratios, fast responses, good colouration efficiency and excellent cycling stability.

An integrated circuit fabricated using industry-standard 40 nm complementary metal–oxide–semiconductor technology can combine silicon quantum devices, digital addressing and analogue multiplexed dispersive readout electronics.