wanglin

Abstract

Two-dimensional (2D) transition metal dichalcogenide (TMDC) monolayers, a class of ultrathin materials with a direct bandgap and high exciton binding energies, provide an ideal platform to study the photoluminescence (PL) of light-emitting devices. Atomically thin TMDCs usually contain various defects, which enrich the lattice structure and give rise to many intriguing properties. As the influences of defects can be either detrimental or beneficial, a comprehensive understanding of the internal mechanisms underlying defect behaviour is required for PL tailoring. Herein, recent advances in the defect influences on PL emission are summarized and discussed. Fundamental mechanisms are the focus of this review, such as radiative/nonradiative recombination kinetics and band structure modification. Both challenges and opportunities are present in the field of defect manipulation, and the exploration of mechanisms is expected to facilitate the applications of 2D TMDCs in the future.

Abstract

Since Moore’s law in the traditional semiconductor industry is facing shocks, More Moore and More than Moore are proposed as two paths to maintain the development of the semiconductor industry by adopting new architectures or new materials, in which the former is committed to the continued scaling of transistors for performance enhancement, and the latter pursues the realization of functional diversification of electronic systems. Two-dimensional (2D) materials are supposed to play an important role in these two paths. In More Moore, the ultimate thin thickness and the dangling-bond-free surface of 2D channels offer excellent gate electrostatics while avoiding the degradation of carrier mobility at the same time, so that the transistors can be further scaled down for higher performance. In More than Moore, devices based on 2D materials can well meet the requirements of electronic systems for functional diversity, like that they can operate at high frequency, exhibit excellent sensitivity to the changes in the surroundings at room temperature, have good mechanical flexibility, and so on. In this review, we present the application of 2D materials in More Moore and More than Moore domains of electronics, outlining their potential as a technological option for logic electronics, memory electronics, radio-frequency electronics, sensing electronics, and flexible electronics.

Abstract

Doping of semiconductors, i.e., accurately modulating the charge carrier type and concentration in a controllable manner, is a key technology foundation for modern electronics and optoelectronics. However, the conventional doping technologies widely utilized in silicon industry, such as ion implantation and thermal diffusion, always fail when applied to two-dimensional (2D) materials with atomically-thin nature. Surface charge transfer doping (SCTD) is emerging as an effective and non-destructive doping technique to provide reliable doping capability for 2D materials, in particular 2D semiconductors. Herein, we summarize the recent advances and developments on the SCTD of 2D semiconductors and its application in electronic and optoelectronic devices. The underlying mechanism of STCD processes on 2D semiconductors is briefly introduced. Its impact on tuning the fundamental properties of various 2D systems is highlighted. We particularly emphasize on the SCTD-enabled high-performance 2D functional devices. Finally, the challenges and opportunities for the future development of SCTD are discussed.