Becquerel cells

The photovoltaic effect, where an internal elecromotive force is created, was discovered by Becquerel (106) in 1839 in an electrolyte with selenium but the effect in a metal—Se contact was first reported by Adams and Day (107) in 1876. The first practical photovoltaic cell was constmcted by Uljanin (108) in 1888. 

In 1839 Alexandre-Edmtmd Becquerel, a French experimental physicist, did the earliest recorded experiments with the photovoltaic effect. Becquerel discovered the photovoltaic effect while experimenting with an electrolytic cell made up of two metal... 

The first observations of photoelectrochemical phenomena were made in 1839 by Antoine Becquerel (1788-1879). He used symmetric galvanic cells consisting of two identical metal electrodes in a dilute acid. When illuminating one of the electrodes he observed current flow in the closed electric circuit. 

The electrochemical photovoltaic effect was discovered in 1839 by A. E. Becquerelt when a silver/silver halide electrode was irradiated in a solution of diluted HN03. Becquerel also first described the photogalvanic effect in a cell consisting of two Pt electrodes, one immersed in aqueous and the other in ethanolic solution of Fe(C104)3. This discovery was made about the same time as the observation of the photovoltaic effect at the Ag/AgX electrodes. The term Becquerel effect often appears in the old literature, even for denoting the vacuum photoelectric effect which was discovered almost 50 years later. The electrochemical photovoltaic effect was elucidated in 1955 by W. H. Brattain and G. G. B. Garrett the theory was further developed... 

In 1896, Antonio Henri Becquerel (1852-1908) made a new type of battery and used a carbon rod. Ludwig Mond and Carl Langer produced a gas-powered battery and called their system a fuel cell in 1889. In 1889, Ludwig Mond (1838-1909) and assistant Carl Langer described their experiments with a hydrogen-oxygen fuel cell that attained 6 A (ampere) per square foot at 0.73 V. Mond and Langer s cell used electrodes of thin, perforated platinum. 

The recorded development of solar cell technology begins with the 1839 research of French experimental physicist Antoine-Edmond Becquerel [46,47]. At the age of nineteen he discovered the... 

Blood.1—The defibrinated blood of a dog was submitted to electrolysis by Becquerel. He made use of platinum electrodes and a current furnished by a battery of three Daniell cells. At the negative pole he observed the following phenomena ... 

Mar. 8,1788, Chatillon-sur-Loing, France - Jan. 18,1878, Paris, France) French scientist, professor of physics at the Museum of Natural History (Paris), developed the Constant Current Cell , but received recognition for this cell only in France whereas elsewhere the almost identical cell is called -> Daniell cell (- Daniell). Becquerel helped in validating -> Faradays law, extensively studied metal deposition in particular in metallurgy and... 

Electrocapillaric Becquerel phenomenon - Becque-rel [i] discovered the phenomenon that at membranes separating a metal solution containing a metal ion, e.g., of copper nitrate, from a solution of sodium sulfide, a metal salt (e.g., copper sulfide) precipitates on which crystals of the metal grow into the metal solution and sulfide is oxidized on the side of the sodium sulfide solution. The effect is only observed when the precipitated salt is a semiconductor. The effect is due to the formation of a —> galvanic cell with the semiconductor as the electronic conductor bridging the two solutions and some electrolyte pores in the membrane forming the ionic conductor [ii]. 

The dimension is s , and the unit is called becquerel (Bq) 1 Bq = 1 s . An older unit is the curie (Ci). It is still used sometimes, related to the activity of Ig of Ra, and defined as 1 Ci = 3.700 lO s = 37GBq. Smaller units are 1 milli-curie (mCi) = 37MBq, 1 microcurie (ixCi) = 37kBq, 1 nanocurie (nCi) = 37 Bq, and 1 picocurie (pCi) = 0.37 Bq. 1 Ci is a rather high activity which cannot be handled directly but needs special installations, such as hot cells. Activities of the order of several mCi are applied in medicine for diagnostic purposes, activities of the order of 1 pCi are usually sufficient for the investigation of the behaviour of radionuclides, and activities of the order of 1 nCi are measurable without special efforts. 

In addition to his scientific discoveries, Becquerel may have been the first person to suffer radiation bums. In 1890, he carried a vial containing a small sample of radium in the breast pocket of his jacket. He developed a wound that looked like a burn but that did not heal for several months. The danger of radiation to cells would not be understood for many years and was probably a factor in the death by cancer of a number of scientists. 

Up to now, only electron beam accelerators and gamma rays cells (Fig. 1) were used for commercial applications. The power of these facilities is measured in watts for electron beam accelerators, in becquerels for gamma-rays irradiators in this last case, we generally speak of activity, instead of power 1 becquerel (Bq) corresponds to a source where one disintegration happens per second (the old unit, 1 Ci = 3.7 x lO Bq). 

Muller R. H. and Spector A. (1932), The Becquerel effect as a special case of the barrier-layer photoelectric cell , Phys. Rev. 41, 371-372. 

In 1839 in Paris, nineteen year old experimenter Edmund Becquerel discovered the photovoltaic effect when he found that certain materials would produce electricity when exposed to light. In that same year William Grove experimented with reversing the process of electrolysis and invented the first gas battery or fuel cell. In the 21st century, these three discoveries converge in photovoltaic fuel cell system technology. 

Antoine Cesar Becquerel in France (1855) and Pavel Yablochkov in Russia (1877) have built electrochemical devices, using coal anodes in a molten potassium nitrate electrolyte. William Jacques (1896) obtained a US patent for his invention of a coal stack with a coal anode and an iron cathode immersed into molten alkali hydroxide. Despite the great doubts raised, as to the nature of the processes taking place in the stack, the electrical performance of this fuel cell stack, operating at temperatures from 400 to 500°C, had a rather impressive total power 1.5 kW, and current densities up to... 

The galvanoplastic phenomena of depositing a metal as part of a cell had been anticipated in similar cells by C. Sylvester, of Sheffield, and N. W. Fischer, which, like Dobereiner s, were early forms of constant cells before Becquerel s couple a oxygene (see p. 131). ... 

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