With large surface-to-volume ratios and Debye length comparable to their small sizes, one-dimensional inorganic nanostructures have extensively been investigated and widely used to fabricate high-performance nanoscale electronic and optoelectronic devices This feature article reviews the state-of-the-art research activities that focus on the one-dimensional inorganic nanostructures and their photodetector applications It begins with a survey of one-dimensional inorganic nanostructures and the fundamentals of photodetectors Some remarkable photoresponse characteristics are then presented, which are organized into sections covering several kinds of important nanostructures, such as ZnO, V 2 O 5 , ZnS, In 2 Se 3 , InSe, CdS, CdSe, ZnSe, Sb 2 Se 3 , ZrS 2 , Ag 2 S, and Zn x Cd 1-x Se Each section describes the corresponding photodetective properties in detail Finally, the article concludes with some perspectives and outlook on the future developments in the field

Recent Developments in One-Dimensional Inorganic Nanostructures for Photodetectors

Magnetoresistive polyaniline-magnetite nanocomposites with negative dielectrical properties

Element doping has been extensively attempted to develop visible-light-driven photocatalysts, which introduces impurity levels and enhances light absorption However, the dopants can also become recombination centers for photogenerated electrons and holes To address the recombination challenge, we report a gradient phosphorus-doped CdS (CdS-P) homojunction nanostructure, creating an oriented built-in electric-field for efficient extraction of carriers from inside to surface of the photocatalyst The apparent quantum efficiency (AQY) based on the cocatalyst-free photocatalyst is up to 82% at 420 nm while the H2 evolution rate boosts to 1943 μmol·h–1·mg–1, which is 583 times higher than that of pristine CdS This concept of oriented built-in electric field introduced by surface gradient diffusion doping should provide a new approach to design other types of semiconductor photocatalysts for efficient solar-to-chemical conversion

Oriented built-in electric field introduced by surface gradient diffusion doping for enhanced photocatalytic H2 evolution in CdS nanorods

Magnetic graphene for microwave absorbing application: Towards the lightest graphene-based absorber

Graphene, a single two-dimensional sheet of carbon atoms with an arrangement mimicking the honeycomb hexagonal architecture, has captured immense interest of the scientific community since its isolation in 2004. Besides its extraordinarily high electrical conductivity and surface area, graphene shows a long spin lifetime and limited hyperfine interactions, which favors its potential exploitation in spintronic and biomedical applications, provided it can be made magnetic. However, pristine graphene is diamagnetic in nature due to solely sp2 hybridization. Thus, various attempts have been proposed to imprint magnetic features into graphene. The present review focuses on a systematic classification and physicochemical description of approaches leading to equip graphene with magnetic properties. These include introduction of point and line defects into graphene lattices, spatial confinement and edge engineering, doping of graphene lattice with foreign atoms, and sp3 functionalization. Each magnetism-imprinting strategy is discussed in detail including identification of roles of various internal and external parameters in the induced magnetic regimes, with assessment of their robustness. Moreover, emergence of magnetism in graphene analogues and related 2D materials such as transition metal dichalcogenides, metal halides, metal dinitrides, MXenes, hexagonal boron nitride, and other organic compounds is also reviewed. Since the magnetic features of graphene can be readily masked by the presence of magnetic residues from synthesis itself or sample handling, the issue of magnetic impurities and correct data interpretations is also addressed. Finally, current problems and challenges in magnetism of graphene and related 2D materials and future potential applications are also highlighted.

Emerging chemical strategies for imprinting magnetism in graphene and related 2D materials for spintronic and biomedical applications

Graphite oxide (GO) and reduced graphene oxide (RGO) have been prepared using standard chemical methods. The formations of the oxides are characterized by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) studies. Both the oxides exhibit weak superparamagnetism and hysteresis for the first time at room temperature. Magnetic moment for RGO is comparatively smaller than that of GO sample. The superparamagnetism in these oxides is attributed to the presence of single domains, each domain being cluster of defect induced magnetic moments coupled by ferromagnetic interaction. Apart from these single domain clusters there are other defect induced moments coupled by ferromagnetic interaction which show ferromagnetism and hysteresis.

A. Nayak

Papers

Magnetic properties of graphite oxide and reduced graphene oxide

Microstructure, dielectric response and electrical properties of polypyrrole modified (poly N-vinyl carbazole–Fe3O4) nanocomposites

Derivative spectra of polycrystalline zn3p2 thin films

Tuning of near infrared excitonic emission from InAs quantum dots by controlling the sub-monolayer coverage

Strong temperature and substrate effect on ZnO nanorod flower structures in modified chemical vapor condensation growth