Co-Rich ZnCoO Nanoparticles Embedded in Wurtzite Zn 1– x Co x O Thin Films: Possible Origin of Superconductivity

Kumar

2019

Ind. Eng. Chem. Res.

185

ZnO nanoparticles are still a hot area for research even after ample work has been done by researchers across the world. It is a versatile material for doping of different transition metals among other metal oxides. Having a large family of morphological structures, high electron mobility, and n-type carrier defects, it is suitable for a number of applications such as memory devices, spintronics, optoelectronic devices, solar cells, and sensors. Here, we have emphasized a review of the effects of transition metal (TM) doping on the different physical properties of ZnO nanoparticles and their applications. We have gone through some theoretical models which were used by most of the researchers for explaining the variations in physical properties. Explanation of the sensing, photocatalytic, and optoelectronic processes in different classes of devices is briefly described. Lastly, the comparative studies of different devices are also made available for clear understanding.

Section: Industrial and Engineering Chemistry Researchmentioning

confidence: 99%

Section: Transition Metal Doping In Znomentioning

confidence: 99%

Progress on Transition Metal-Doped ZnO Nanoparticles and Its Application

Kumar

2019

Ind. Eng. Chem. Res.

185

Advanced Optical Materials

“…Given all these superior properties of 2D α‐C:H, self‐powered flexible photodetectors are fabricated by incorporation of the nanosheets with the ZnO film, one of the most extensively investigated semiconductors used in UV photodetectors owing to its wide bandgap (3.37 eV), high room‐temperature exciton binding energy (60 meV), and earth‐abundant, nontoxic characters. [ 20 ] Remarkable photoresponse has been achieved, especially an extended photoresponse range, a high responsivity of 195.16 mA W −1 , and 267‐fold rise‐time shortening. The fundamentals of these performance enhancements are congruously derived from the type II heterogeneous integration, the piezo‐phototronic effect, and the pyroelectric effect.…”

Section: Introductionmentioning

confidence: 99%

2D Allotrope of Carbon for Self‐Powered, Flexible, and Transparent Optoelectronics

Guo

Chen

Jin

et al. 2020

Flexible and transparent optoelectronics based on 2D materials are promising candidates for next‐generation technologies. Among all 2D materials, it is of numerous practical implications to explore nonmetal, earth‐abundant candidates. Herein, an exciting addition is unearthed—2D hydrogenized amorphous carbon (α‐C:H). The 2D α‐C:H nanosheets, with layered structural feature, are composed of crystalline sp2 nanoclusters embedded in sp3 amorphous matrix. The typical “vapor–solid” mechanism governs the growth of these nanosheets under the temperature–pressure combination above the Berman–Simon line. Their high transmittance over 97.7% covers the 425–1300 nm wavelength region. Optical characterizations also reveal a spectral overlap between the π–π* absorption edge and σ–σ* photoluminescence peak. Self‐powered and flexible photodetectors based on the 2D α‐C:H/ZnO heterostructure exhibit a remarkable photoresponse, with a broadened photosensitivity responsivity of 195.16 mA W−1 and a 267‐fold decrease of the rise time. This performance enhancement originates from the type II band alignment, the pyroelectric and piezo‐phototronic effects. As a new member in the 2D family, α‐C:H nanosheets promise to be appealing in transparent flexible optoelectronics with ultralow power consumption and real‐time, on‐site response.

“…Recently, a few research activities have been directed toward the development of heavily doping ferromagnetic semiconductors. − However, the technical realization of single phase semiconductor material with a high concentration of magnetic dopants remains a challenge. In the present work, we succeeded in growing wurtzite Co x Zn 1– x O 1‑ v single crystalline films with x up to 0.45 under conditions far from thermodynamic equilibrium.…”

Section: Introductionmentioning

confidence: 99%

Growth-Controlled Engineering of Magnetic Exchange Interactions in Single Crystalline GaCoZnO_1-v Epitaxial Films with High Co Concentration

Cao

Zhu

et al. 2017

Chem. Mater.

While semiconductor spintronics promises lower switching energy and faster speed, a major limitation on its development as a viable technology is the lack of room temperature ferromagnetic semiconductor materials. The material challenge is great, because not only magnetic and electronic doping but also thermally robust coupling between them are required for a room temperature ferromagnetic semiconductor. Here, we report the growth-controlled engineering of magnetic exchange interactions in single crystalline GaCoZnO 1-v epitaxial films with high Co concentrations (0.3 ≤ x ≤ 0.45) by controlling oxygen vacancy and carrier density through Ga 3+ doping. Strong ferromagnetism, spin-split impurity states, and spin-polarized electrical transport are realized and well controlled at room temperature by tailoring the s,p−d exchange coupling. This room temperature ferromagnetic semiconductor, which offers the ability to individually control carrier density and magnetic doping, will lay a solid foundation for the development of practical spintronic devices operating at room temperature.