Semiconductors germanium preparation

A new family of hexagonal mesoporous all-germanium semiconductors was prepared by the surfactant-assisted cross-linking polymerization reaction of Zintl [Geg]" anions (Scheme 1) with Ge(lV) bridges in formamide/ethylenediamine solution (1) [43]. 

In some materials, semiconductors in particular, interstitial atoms play a crucial role in diffusion. Thus, Frank and Turnbull (1956) proposed that copper atoms dissolved in germanium are present both substitutionally (together with vacancies) and interstitially, and that the vacancies and interstitial copper atoms diffuse independently. Such diffusion can be very rapid, and this was exploited in preparing the famous micrograph of Figure 3.14 in the preceding chapter. Similarly, it is now recognised that transition metal atoms dissolved in silicon diffuse by a very fast, predominantly interstitial, mechanism (Weber 1988). 

Organogermanium compounds, including tetramethyl- and tetraethylgermanium, are used in the semiconductor industry to prepare deposits of germanium. Spirogermanium,... 

Elemental germanium is used primarily in the preparation of semiconductors in which it is combined with phosphorus, arsenic, or antimony to make n-type semiconductors or with gallium to make p-type semiconductors. 

Zone refining was developed originally to produce very pure germanium for the semiconductor industry. It Was successful in that Bell Laboratories produced 99.99999999 % pure germanium Since then, many elements have been prepared in high purity, as well as many organic compounds. 

A method combining laser ablation cluster formation and vapor-liquid-solid (VLS) growth was recently developed for the synthesis of single crystal semiconductor siiicon and germanium nanowhiskers [74], Specificaily, iaser abiation was used to prepare dusters of moiten metal catalyst particles with a nanometer diameter. The droplet diameter defines the diameter of the resulting nanowhiskers. Buik quantities of uniform silicon and germanium nanowhiskers with diameters from 6 to 20 and from 3 to 9 nanometers, respectiveiy, and lengths from 10 to 300 nanometers were obtained. 

An isotope dose calibrator is shaped as a cylinder and is often built in beneath the working area in the safety cabinet. It measures the radioactivity of a prepared dose in a vial or syringe. Each individual radionuclide can be measured accurately. Other equipment to measure radioactivity are scintillation counters (e.g. the Nal well counter) and semiconductor-based instruments (e.g. the Germanium detector). 

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