There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

There is a special reason for reviewing this book at this time: it is the 50th edition of a compendium that is known and used frequently in most chemical and physical laboratories in many parts of the world. Surely, a publication that has been published for 56 years, withstanding the vagaries of science in this century, must have had something to offer. There is another reason: while the book is a standard fixture in most chemical and physical laboratories, including those in medical centers, it is not as frequently seen in the laboratories of physician's offices (those either in solo or group practice). I believe that the Handbook can be useful in those laboratories. One of the reasons, among others, is that the various basic items of information it offers may be helpful in new tests, either physical or chemical, which are continuously being published. The basic information may relate

Handbook of Chemistry and Physics

https://chemistry.beloit.edu/classes/nanotech/ZnO/mattoday10_05_40.pdf

ZnO - nanostructures, defects, and devices

We present a review of current research on the optical properties of ZnO nanostructures. We provide a brief introduction to different fabrication methods for various ZnO nanostructures and some general guidelines on how fabrication parameters (temperature, vapor-phase versus solution-phase deposition, etc.) affect their properties. A detailed discussion of photoluminescence, both in the UV region and in the visible spectral range, is provided. In addition, different gain (excitonic versus electron hole plasma) and feedback (random lasing versus individual nanostructures functioning as Fabry-Perot resonators) mechanisms for achieving stimulated emission are described. The factors affecting the achievement of stimulated emission are discussed, and the results of time-resolved studies of stimulated emission are summarized. Then, results of nonlinear optical studies, such as second-harmonic generation, are presented. Optical properties of doped ZnO nanostructures are also discussed, along with a concluding outlook for research into the optical properties of ZnO.

Optical properties of ZnO nanostructures.

Photovoltaic (PV) technologies for solar energy conversion represent promising routes to green and renewable energy generation. Despite relevant PV technologies being available for more than half a century, the production of solar energy remains costly, largely owing to low power conversion efficiencies of solar cells. The main difficulty in improving the efficiency of PV energy conversion lies in the spectral mismatch between the energy distribution of photons in the incident solar spectrum and the bandgap of a semiconductor material. In recent years, luminescent materials, which are capable of converting a broad spectrum of light into photons of a particular wavelength, have been synthesized and used to minimize the losses in the solar-cell-based energy conversion process. In this review, we will survey recent progress in the development of spectral converters, with a particular emphasis on lanthanide-based upconversion, quantum-cutting and down-shifting materials, for PV applications. In addition, we will also present technical challenges that arise in developing cost-effective high-performance solar cells based on these luminescent materials.

Enhancing solar cell efficiency: the search for luminescent materials as spectral converters

Room-Temperature Lasing Observed from ZnO Nanocolumns Grown by Aqueous Solution Deposition

Laser emission in the range of 1.88-1.99 μm from a Tm3+-doped tellurite fiber is demonstrated when pumped with a diode-pumped Er3+/Yb3+-doped silica fiber laser operating at 1.57-1.61 μm. This pump source excites the Tm3+ ions directly into the F43 upper laser level and yields an output power of 280 mW with a slope efficiency of 76% in a 99%-12% laser cavity arrangement and a 32 cm long fiber. This result is very close to the Stokes efficiency limit of ~80%. This is, to the authors' knowledge, the first demonstration of high efficiency lasing in a tellurite fiber at wavelengths longer than 1.56 μm.

/pdf/efficient-2-mm-tm-3-doped-tellurite-fiber-laser-2kd2t6wxd1.pdf

Efficient ~2 μm Tm 3+ -doped tellurite fiber laser

Recent work in the area of Tm 3+ and Ho 3+ -doped tellurite fibre and bulk glass lasers operating close to 2 μm is re- viewed. Spectroscopic properties of these doped glasses are dis- cussed as well as the relevant pump schemes and energy trans- fer processes involved. Results of continuous wave (CW) and Q-switched Tm 3+ and Ho 3+ -doped tellurite fibre lasers are then presented and discussed. Finally, the results of tellurite bulk glass laser experiments conducted to date are reported.

Tellurite glass lasers operating close to 2 μm

Stuart K. Stubbs,1 Samantha J. O. Hardman,1 Darren M. Graham,1 Ben F. Spencer,1,2 Wendy R. Flavell,1 Paul Glarvey,3 Ombretta Masala,3 Nigel L. Pickett,3 and David J. Binks1,* 1School of Physics and Astronomy and the Photon Science Institute, The University of Manchester, Manchester M13 9PL, United Kingdom 2Cockcroft Institute, STFC Daresbury Laboratory, Warrington, Cheshire WA4 4AD, United Kingdom 3Nanoco Technologies Ltd., Grafton Street, Manchester M13 9NT, United Kingdom Received 26 October 2009; published 16 February 2010

Efficient carrier multiplication in InP nanoparticles

The infrared emission spectra and decay lifetimes of Tm(3+)-doped and Tm(3+)-Ho(3+), Tm(3+)-Yb(3+) co-doped tellurite fibres were measured using 808 nm and 978 nm diode laser pump sources in the range 1.35 mum to 2.2 mum. The spectra were compared with varying fibre lengths and core diameters. Tm(3+)-doped fibre shows strong emission at ~1.8 mum and when co-doped with Ho(3+), energy transfer results in strong Ho(3+) fluorescence at ~2.0 mum. These fibres show promise for compact mid-IR fibre laser sources.

David J. Binks

Papers

Room-Temperature Lasing Observed from ZnO Nanocolumns Grown by Aqueous Solution Deposition

Efficient ~2 μm Tm 3+ -doped tellurite fiber laser

Tellurite glass lasers operating close to 2 μm

Efficient carrier multiplication in InP nanoparticles

Infrared emission and energy transfer in Tm 3+ , Tm 3+ -Ho 3+ and Tm 3+ -Yb 3+ -doped tellurite fibre