Science Current Events | Science News |

Metal oxides hold the key to cheap, green energy

April 19, 2012

BINGHAMTON, NY - Harnessing the energy of sunlight can be as simple as tuning the optical and electronic properties of metal oxides at the atomic level by making an artificial crystal or super-lattice 'sandwich' says a Binghamton University researcher in a new study published in the journal Physical Review B.

"Metal oxides are cheap, abundant and 'green,'" said Louis Piper, assistant professor of physics at Binghamton University. "And as the study proved, quite versatile. With the right touch, metal oxides can be tailored to meet all sorts of needs, which is good news for technological applications, specifically in energy generation and flat screen displays."

Here's how it works: semiconductors are an important class of materials in between metals and insulators. They are defined by the size of their band gap, which represents the energy required to excite an electron from the occupied shell to an unoccupied shell where it can conduct electricity. Visible light covers a range of 1 (infrared) to 3 (ultraviolet) electron volts. For transparent conductors, a large band gap is required, whereas for artificial photosynthesis, a band gap corresponding to green light is needed. Metal oxides provide a means of tailoring the band gap.

But while metal oxides are very good at electron conduction, they are very poor "hole" conductors. Holes refer to absence of electrons, and can conduct positive charge. To maximize their technologically potential, especially for artificial photosynthesis and invisible electronics, hole conducting metal oxides are required.

Knowing this, Piper has begun studying layered metal oxides systems, which can be combined to selectively 'dope' (replace a small number of one type of atom in the material), or 'tune' (control the size of the band gap). Recent work revealed that a super-lattice of two hole-conducting copper oxides could cover the entire solar spectrum. The goal is to improve the performance whilst using environmentally benign and cheap metal alternatives.

For instance, indium oxide is one of the most widely used oxides used in the production of coatings for flat screen displays and solar cells. It can conduct electrons really well and is transparent. But it is also rare and very expensive. Piper's current research is aimed towards using much cheaper tin oxide layers to get electron and hole conduction with optical transparency.

But according to Piper, his research shows that one glove will not fit all purposes.

"It's going to be a case of some serious detective work," said Piper. "We're working in a world where physics and chemistry overlap. And we've reached the theoretical limit of our calculations and fundamental processes. Now we need to audit those calculations and see where we're missing things. I believe we will find those missing pieces by playing around with metal oxides."

By reinforcing metal oxides' 'good bits' and downplaying the rough spots, Piper is convinced that the development of new and exciting types of metal oxides that can be tailored for specific applications are well within our reach.

"We're talking battery storage, fuel cells, touch screen technology and all types of computer switches," said Piper. "We're in the middle of a very important gold rush and its very exciting to be part of that race to strike it rich. But first we have to figure out what we don't know before we can figure out what we do. One thing's for sure: metal oxides hold the key. And I believe that we at Binghamton University can contribute to these efforts by doing good science and taking a morally conscious approach."

Binghamton University

Related Metal Oxides Current Events and Metal Oxides News Articles

Revealing the nature of magnetic interactions in manganese oxide
For nearly 60 years, scientists have been trying to determine how manganese oxide (MnO) achieves its long-range magnetic order of alternating up and down electron spins.

NREL, SLAC scientists pinpoint solar cell manufacturing process
Scientists at the Energy Department's National Renewable Energy Laboratory (NREL) and SLAC National Accelerator Laboratory have been able to pinpoint for the first time what happens during a key manufacturing process of silicon solar cells.

Pumping up energy storage with metal oxides
Material scientists at Lawrence Livermore National Laboratory have found certain metal oxides increase capacity and improve cycling performance in lithium-ion batteries.

Chemically storing solar power
Nature shows us how it is done: Plants can absorb sunlight and store its energy chemically. Imitating this on large industrial scale, however, is difficult.

Lithium battery catalyst found to harm key soil microorganism
The material at the heart of the lithium ion batteries that power electric vehicles, laptop computers and smartphones has been shown to impair a key soil bacterium, according to new research published online in the journal Chemistry of Materials.

Host-guest nanowires for efficient water splitting and solar energy storage
California is committed to 33 percent energy from renewable resources by 2020. With that deadline fast approaching, researchers across the state are busy exploring options.

New type of nanowires, built with natural gas heating
A team of Korean researchers, affiliated with UNIST has recently pioneered in developing a new simple nanowire manufacturing technique that uses self-catalytic growth process assisted by thermal decomposition of natural gas.

Switchable material could enable new memory chips
Two MIT researchers have developed a thin-film material whose phase and electrical properties can be switched between metallic and semiconducting simply by applying a small voltage.

Microwaves improve green workings of materials used to clean wastewater
A new method for making the material used for cleaning wastewater makes the production process greener - and 20 times faster.

Monolithic perovskite/silicon tandem solar cell achieves record efficiency
Organic-inorganic perovskite materials are one of the biggest surprises in solar cell research. In just six years, the efficiency of perovskite solar cells has increased five-fold; moreover, perovskite solar cells can be manufactured from solution and be cost-effectively printed on large areas in the future.
More Metal Oxides Current Events and Metal Oxides News Articles

Frontiers of 4d- and 5d-Transition Metal Oxides

Frontiers of 4d- and 5d-Transition Metal Oxides
by Gang Cao (Author), Gang Cao (Editor), Lance De-Long (Editor)

This book is aimed at advanced undergraduates, graduate students and other researchers who possess an introductory background in materials physics and/or chemistry, and an interest in the physical and chemical properties of novel materials, especially transition metal oxides. New materials often exhibit novel phenomena of great fundamental and technological importance. Contributing authors review the structural, physical and chemical properties of notable 4d- and 5d-transition metal oxides discovered over the last 10 years. These materials exhibit extraordinary physical properties that differ significantly from those of the heavily studied 3d-transition metal oxides, mainly due to the relatively strong influence of the spin-orbit interaction and orbital order in 4d- and 5d materials. The...

The Surface Science of Metal Oxides

The Surface Science of Metal Oxides
by Victor E. Henrich (Author), P. A. Cox (Author)

This book is the first to give a comprehensive account of the fundamental properties of metal-oxide surfaces and their interaction with atoms, molecules and overlayers. The surfaces of metal oxides play a crucial role in an extremely wide range of phenomena, including the environmental degradation of high-Tc superconductors and catalysis. They are also increasingly important in processes such as the passivation of metal surfaces and gas sensing for pollution monitoring and control. As well as giving a general overview of the properties of metal-oxides, an extensive and thorough compilation of the research that has been performed on well characterised oxide surfaces is provided, thus making the book suitable for those graduate students and established researchers in materials science,...

Functional Metal Oxide Nanostructures (Springer Series in Materials Science)

Functional Metal Oxide Nanostructures (Springer Series in Materials Science)
by Junqiao Wu (Editor), Jinbo Cao (Editor), Wei-Qiang Han (Editor), Anderson Janotti (Editor), Ho-Cheol Kim (Editor)

Metal oxides and particularly their nanostructures have emerged as animportant class of materials with a rich spectrum of properties and greatpotential for device applications. In this book, contributions from leadingexperts emphasize basic physical properties, synthesis and processing, and thelatest applications in such areas as energy, catalysis and data storage.  Functional Metal Oxide Nanostructuresis an essential reference for any materials scientist or engineer with aninterest in metal oxides, and particularly in recent progress in defectphysics, strain effects, solution-based synthesis, ionic conduction, and theirapplications.

Metal Oxides: Chemistry and Applications (Chemical Industries)

Metal Oxides: Chemistry and Applications (Chemical Industries)
by J.L.G. Fierro (Editor)

The chemistry of metals has traditionally been more understood than that of its oxides. As catalytic applications continue to grow in a variety of disciplines, Metal Oxides: Chemistry and Applications offers a timely account of transition-metal oxides (TMO), one of the most important classes of metal oxides, in the context of catalysis.

The first part of the book examines the crystal and electronic structure, stoichiometry and composition, redox properties, acid-base character, and cation valence states, as well as new approaches to the preparation of ordered TMO with extended structure of texturally defined systems. The second part compiles some practical aspects of TMO applications in materials science, chemical sensing, analytical chemistry, solid-state chemistry,...

Metal Oxide Nanostructures as Gas Sensing Devices (Series in Sensors)

Metal Oxide Nanostructures as Gas Sensing Devices (Series in Sensors)
by G. Eranna (Author)

Metal Oxide Nanostructures as Gas Sensing Devices explores the development of an integrated micro gas sensor that is based on advanced metal oxide nanostructures and is compatible with modern semiconductor fabrication technology. This sensor can then be used to create a compact, low-power, handheld device for analyzing air ambience. The book first covers current gas sensing tools and discusses the necessity for miniaturized sensors. It then focuses on the materials, devices, and techniques used for gas sensing applications, such as resistance and capacitance variations. The author addresses the issues of sensitivity, concentration, and temperature dependency as well as the response and recovery times crucial for sensors. He also presents techniques for synthesizing different metal...

Transition Metal Oxides: An Introduction to Their Electronic Structure and Properties (The International Series of Monographs on Chemistry)

Transition Metal Oxides: An Introduction to Their Electronic Structure and Properties (The International Series of Monographs on Chemistry)
by P.A. Cox (Author)

Transition metal oxides form a series of compounds with a uniquely wide range of electronic properties. They have important applications as dielectrics, semiconductors and metals, and as materials for magnetic and optical uses. The discovery of high temperature superconductors has brought the attention of a wide scientific community to this area and has highlighted the problems involved in trying to understand transition metal oxides. The present book is not primarily about Tc superconductors, although their main properties are discussed in the final sections. The main aim is to describe the varied electronic behaviour shown by transition metal oxides, and to discuss the different types of theoretical models that have been proposed to interpret this behaviour.

Physics of Transition Metal Oxides (Springer Series in Solid-State Sciences) (v. 144)

Physics of Transition Metal Oxides (Springer Series in Solid-State Sciences) (v. 144)
by Sadamichi Maekawa (Author), Takami Tohyama (Author), Stewart Edward Barnes (Author), Sumio Ishihara (Author), Wataru Koshibae (Author), Giniyat Khaliullin (Author)

The fact that magnetite (Fe304) was already known in the Greek era as a peculiar mineral is indicative of the long history of transition metal oxides as useful materials. The discovery of high-temperature superconductivity in 1986 has renewed interest in transition metal oxides. High-temperature su­ perconductors are all cuprates. Why is it? To answer to this question, we must understand the electronic states in the cuprates. Transition metal oxides are also familiar as magnets. They might be found stuck on the door of your kitchen refrigerator. Magnetic materials are valuable not only as magnets but as electronics materials. Manganites have received special attention recently because of their extremely large magnetoresistance, an effect so large that it is called colossal...

The Defect Chemistry of Metal Oxides (Monographs on the Physics & Chemistry of Materials (Hardcover))

The Defect Chemistry of Metal Oxides (Monographs on the Physics & Chemistry of Materials (Hardcover))
by D. M. Smyth (Author)

The Defect Chemistry of Metal Oxides is a unique introduction to the equilibrium chemistry of solid inorganic compounds with a focus on metal oxides. Accessible to students with little or no background in defect chemistry, it explains how to apply basic principles and interpret the related behavior of materials. Topics discussed include lattice and electronic defects, doping effects, nonstoichiometry, and mass and charge transport. The text distinctly emphasizes the correlation between the general chemical properties of the constituent elements and the defect chemistry and transport properties of their compounds. It covers the types of defects formed, the effects of dopants, the amount and direction of nonstoichiometry, the depths of acceptor and donor levels, and more. Concluding...

Nonstoichiometry, Diffusion and Electrical Conductivity in Binary Metal Oxides (Science & Technology of Materials)

Nonstoichiometry, Diffusion and Electrical Conductivity in Binary Metal Oxides (Science & Technology of Materials)
by P.K. Kofstad (Author)

  Metal-oxide Semiconductor and Special-purpose Bipolar Integrated Circuits and R-F Power Transistor Circuit Design (Texas Instruments electronics series)
by Texas Instruments Incorporated (Author)

© 2017