Today, two-dimensional materials are one of the key research topics for scientists around the world. Interest in 2D materials is not surprising because, thanks to their remarkable mechanical, thermal, electrical, magnetic, and optical properties, they promise to revolutionize electronics. The unique properties of graphene-like 2D materials give them the potential to create completely new types of devices for functional electronics, nanophotonics, and quantum technologies. This paper considers epitaxially grown two-dimensional allotropic modifications of single elements: graphene (C) and its analogs (transgraphenes) borophene (B), aluminene (Al), gallenene (Ga), indiene (In), thallene (Tl), silicene (Si), germanene (Ge), stanene (Sn), plumbene (Pb), phosphorene (P), arsenene (As), antimonene (Sb), bismuthene (Bi), selenene (Se), and tellurene (Te). The emphasis is put on their structural parameters and technological modes in the method of molecular beam epitaxy, which ensure the production of high-quality defect-free single-element two-dimensional structures of a large area for promising device applications.

Avalanche photodiodes have emerged as a promising technology with significant potential for various medical applications. This article presents an overview of the advancements and applications of avalanche photodiodes in the field of medical imaging. Avalanche photodiodes offer distinct advantages over traditional photodetectors, including a higher responsivity, faster response times, and superior signal-to-noise ratios. These characteristics make avalanche photodiodes particularly suitable for medical-imaging modalities that require a high detection efficiency, excellent timing resolution, and enhanced spatial resolution. This review explores the key features of avalanche photodiodes, discusses their applications in medical-imaging techniques, and highlights the challenges and future prospects in utilizing avalanche photodiodes for medical purposes. Special attention is paid to the recent progress in silicon-compatible avalanche photodiodes.

In this review the latest advances in the field of nanostructured photodetectors are considered, stating the types and materials, and highlighting the features of operation. Special attention is paid to the group-IV material photodetectors, including Ge, Si, Sn, and their solid solutions. Among the various designs, photodetectors with quantum wells, quantum dots, and quantum wires are highlighted. Such nanostructures have a number of unique properties, that made them striking to scientists’ attention and device applications. Since silicon is the dominating semiconductor material in the electronic industry over the past decades, and as germanium and tin nanostructures are very compatible with silicon, the combination of these factors makes them the promising candidate to use in future technologies.