**Preface to "Feature Papers in Electronic Materials Section"**

Today, electronic materials are widespread in our society. In fact, cellular phones and wireless communication systems, computers, energy conversion devices, power modules, solid-state lighting devices, and sensors and detectors, are typically fabricated using a variety of electronic materials (e.g., semiconductors, metals, insulators, etc.) with specific functionalities. Hence, the deep comprehension of the fundamental properties of these materials, the development of their processing technology, and their integration in real electronic devices require continuous efforts from the scientific community.

This book entitled *Feature Papers in Electronic Materials Section*is a collection of selected regular and review papers recently published on the journal Materials, focusing on the latest advances in electronic materials and devices in different fields (e.g., power- and high-frequency electronics, optoelectronic devices, detectors, etc.).

In particular, in the first part of the volume, many papers are dedicated to wide band gap semiconductors (WBG), a class of materials that are pervasively entering the power- and high-frequency electronic devices market, replacing the traditional silicon devices. Among them, silicon carbide (SiC) and gallium nitride (GaN) are the most advanced ones in terms of crystalline quality and technology maturity. In fact, a variety of devices, e.g., Schottky diodes, MOSFETs, HEMTs, MISHEMT, etc., are already commercialized worldwide. In this context, the key technological issues related to contacts, doping, and dielectrics for SiC and GaN devices, together with important reliability issues associated to GaN-on-Si devices, are specifically addressed in some papers. Moreover, the radiation hardness of SiC, useful for detectors applications, and the perspectives of cubic silicon carbide (3C-SiC) materials and devices technology are also discussed. Finally, the current status of some emerging, but still less mature, WBG materials, such as gallium oxide (Ga2O3) and diamond, is also presented. On the other hand, the second part of the volume is a miscellaneous of other electronics materials for various applications, e.g., going from gallium arsenide (GaAs) nanomembranes for HEMT devices, to iron selenide (FeSe) for high-temperature superconductivity and silica for optical communications, up to the popular two-dimensional (2D) materials, such as graphene and molybdenum disulfide (MoS2), which can be applied in both optoelectronic and high-frequency devices. Furthermore, some recent advances in materials and flexible sensors for bioelectronics and medical applications are also reviewed at the end of the book.

> **Fabrizio Roccaforte** *Editor*
