Theoretical investigations of structural, electronic, magnetic, and optical properties of group V (X = V, Nb, Ta) added CeO2-X materials for optoelectronic applications.

CONTEXT: Depletion of natural resources, responsible for energy production, is a serious concern for researchers to develop alternate energy resources or materials. Scientists have proposed various energy materials which are based on semiconductors and their underlying physics. Cerium oxide (CeO2) is a versatile energy material which receives much attention owing to excellent photocatalytic, photonic, thermal stability, and optoelectronic applications. Even though CeO2 exhibited remarkable physical properties, but yet, they can be enhanced upon suitable doping. Focus on current research is to dope group V elements into CeO2 in order to enhance its electronic and optical response. The density of states (DOS) and band gaps of proposed materials are calculated, and significant improvement is noted after applying TB-mbj method. Optical absorption spectra of V/Nb/Ta-doped CeO2 show blueshift and decrease in reflectivity along with the presence of magnetism illustrate potential uses of these materials in future UV optoelectronics, spintronics, sensing, and energy harvesting devices. METHODS: This research is based on computational work carried using Wien2k code where PBE-GGA approximation is used to approximate exchange and correlation potentials. Supercells of vanadium/niobium/tantalum-doped CeO2 are constructed, and spin-polarized density of states (DOS) along with optical constant are calculated. TB-mbj method is used to bring improvements in DOS and band gaps of proposed materials. Iterations are conducted using convergence criterion, and non-relativistic calculations are performed.

Investigating structural, electronic, magnetic, and optical properties of Co-doped and Co-X (X = Fe, Mn) co-doped MoS2 for optoelectronic applications.

We employ first-principle calculations to investigate structural, electronic, magnetic, and optical properties of cobalt and Co-X (X = Fe, Mn) co-doped MoS2. Result demonstrates that pure MoS2 is nonmagnetic, while Co and Co-Fe/Mn co-doping brings magnetism into MoS2 with magnetic moment values of 0 [Formula: see text], 2.022 [Formula: see text], 3.906 [Formula: see text], and 3.643 [Formula: see text] respectively. d states of dopants and p-d hybridization bring significant improvements in electronic properties of MoS2. Novelty of current work lies not only in origin of magnetism in the proposed materials but also in absorption spectra which show blueshift. We notice reduction in optical band gap with Co and Co-Fe/Mn co-doping. Enhanced absorption and conductivity with decrease in reflectivity illustrate potential uses of these materials for revolutionizing future of optoelectronics, spintronics, magneto-optics, and photonics devices. Moreover, crossroads of MoS2 and allied materials may further explore new avenues in sensing, artificial intelligence, and miniaturization of existing technology.