Selenium Rectifier Research Articles

Trailblazers in Solid-State Electronics [Historical

The first person to investigate solid-state effects was the German physicist Karl Ferdinand Braun. It is little known that the first solid-state devices were made much earlier, even before thermionic tubes were conceived. The selenium rectifier was the first solid-state metal diode suitable for more general power uses.

Occupational Exposure to Selenium among Workers in Rubber Tire Repair Shops

Selenium concentration was determined in six tire repair shops in Alexandria. Concentrations of selenium were determined in tire damages repair, electric spot heater, and buffing positions. The results obtained revealed that there was a significant difference between the concentration of selenium in tire damages repair position and its concentration in electric spot heater position [t=2.47, 0.003*]. Also, there was a significant difference between the concentrations of selenium in electric spot heater position and its concentration in buffing position [t=2.86, 0.002*]. But, the difference between the concentrations of selenium in tire damages repair and in buffing positions was not significant. Workers at rubber tire repair shops were exposed to concentrations of selenium in the range of 0.7-7.3 μg/m3. This range is quietly below TLV of selenium [0.2 mg/m3], but this concentration is nearly equal to lower end of range of concentration reported to produce slight tracheobronchitis in 9 out of 62 exposed workers in a selenium rectifier plant. The present study determines the levels of selenium in the environment of rubber tire repair shops and recommends that routes of absorption of selenium other than respiratory and unlimited hours of exposure should be considered while health problem is evaluated.

Wirtschaftswunder in Pretzfeld, upper Franconia: Interactions between science, technology, and corporate strategies in Siemens semiconductor rectifier research & development, 1945–1956

Immediately after World War II, when emergency production of non‐electrotechnical products such as stoves, pots, etc. at Siemens amounted to more than 50% and the return to normal production and old standards was the primary company goal, one man, Eberhard Spenke, thought far ahead. Power semiconductor rectifiers were to be designed and manufactured on a scientific basis rather than as a result of trial and error methods. The theory of rectification in semiconductor‐metal contacts that had been found by the Siemens theoretical physicist Walter H. Schottky was to serve as a starting point. First, apartments for researchers had to be built in a former stable at Pretzfeld Castle, Upper Franconia; lab equipment was then procured. On September 1, 1947, research work began, and the first selenium rectifiers were made on three old kitchen tables. In 1956, Spenke proudly presented the world's first reproducible silicon power rectifier elements (for a reverse voltage of 1000 V and a maximum forward current of 300 A when forced‐air‐cooled) at the international semiconductor conference in Garmisch‐Partenkirchen, Bavaria. Siemens had thus become a world leader in power electronics. The example of Eberhard Spenke and his team can give valuable guidelines for organizing Research & Development efficiently within a big corporation. It shows that the amount of money spent on R&D is not necessarily the determining factor of success. At least equally important are such elements as personal leadership in small research groups rather than bureaucratic administration of research, the ability to foresee technological and market developments, direct contacts between the leading researchers and the top management, open‐mindedness of the top management to new ideas and approaches, and the motivation of employees.

The genotoxicity of selenium

Selenium at nutritional levels has been shown to have numerous anticarcinogenic or preventative effects against carcinogen-induced breast, colon, liver and skin cancer in animals. Many of these anticarcinogenic effects have been summarized. In addition, numerous mutagenic and antimutagenic effects of selenium compounds have been reported. Some of the selenium compounds frequently tested for mutagenicity are listed in Table 1. Because of the numerous reported anticarcinogenic and preventative effects of selenium, many individuals are supplementing their diets with amounts of selenium that are greater than the recommended daily requirement. Selenium is also used widely in industrial products such as selenium rectifiers, photoelectric batteries, alloys and paints. Because selenium at higher levels is known to be toxic, there should be a greater understanding about its genotoxic as well as its beneficial effect. The object of this review is to summarize experimental evidence both for the antimutagenic and the mutagenic effect of selenium.

Electrical forming action in Te-Se-Cd structures

Improved techniques have been developed for the fabrication of rectifying Te-Se-Cd sandwich structures, where the selenium is present as a thin monocrystalline film. The electrical forming action, which has been used for many years to improve the performance of selenium rectifiers, has been investigated in these simple structures. Analysis of capacitance-voltage characteristics indicates that the electrical forming process is a progressive reduction in the concentration of acceptors in the selenium within a region of about half a micrometer from the junction. Scanning-electron microscopy has failed to reveal CdSe at the Cd-Se interface after electrical forming, although this compound is found after thermal forming. The studies indicate that, contrary to previously held views, CdSe is not necessary for the rectification and that the device involves essentially a Schottky junction rather than a heterojunction of n-CdSe and p-Se.

Measurement of semiconductor junction parameters using lock-in amplifiers

A phase-sensitive detection scheme is described that allows the equivalent circuit of semiconductor diodes to be determined over a wide range of operating conditions. Under reverse bias, a direct plot may be obtained of the bias dependence of the exhaustion region width through impedance measurements. In the forward sense, the diode admittance may be measured even when large currents are flowing through the diode. The capability of the method, both to yield valuable information regarding physical conditions at the junction of the device and to give insight into the charge-transport mechanisms at the interface, is illustrated through a series of measurements on selenium rectifiers.

Static relaxation of selenium rectifiers subjected to x-irradiation and a reverse current

Static relaxation of selenium rectifiers subjected to x-irradiation and a reverse current

Piezoresistance effect of a selenium rectifier

physica status solidi (a)Volume 4, Issue 1 p. K53-K57 Short Note Piezoresistance effect of a selenium rectifier M. Seki, M. Seki Electrical Communication Laboratory, Nippon Telegraph, and Telephone Public Corporation, Musashino-shi, TokyoSearch for more papers by this authorY. Mizushima, Y. Mizushima Electrical Communication Laboratory, Nippon Telegraph, and Telephone Public Corporation, Musashino-shi, TokyoSearch for more papers by this authorO. Ochi, O. Ochi Electrical Communication Laboratory, Nippon Telegraph, and Telephone Public Corporation, Musashino-shi, TokyoSearch for more papers by this authorT. Takagi, T. Takagi Electrical Communication Laboratory, Nippon Telegraph, and Telephone Public Corporation, Musashino-shi, TokyoSearch for more papers by this author M. Seki, M. Seki Electrical Communication Laboratory, Nippon Telegraph, and Telephone Public Corporation, Musashino-shi, TokyoSearch for more papers by this authorY. Mizushima, Y. Mizushima Electrical Communication Laboratory, Nippon Telegraph, and Telephone Public Corporation, Musashino-shi, TokyoSearch for more papers by this authorO. Ochi, O. Ochi Electrical Communication Laboratory, Nippon Telegraph, and Telephone Public Corporation, Musashino-shi, TokyoSearch for more papers by this authorT. Takagi, T. Takagi Electrical Communication Laboratory, Nippon Telegraph, and Telephone Public Corporation, Musashino-shi, TokyoSearch for more papers by this author First published: 16 January 1971 https://doi.org/10.1002/pssa.2210040143AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Volume4, Issue116 January 1971Pages K53-K57 RelatedInformation

Some effects of water vapour on selenium rectifiers: H P D Lanyon, Phys Status Solidi (a), 2 (2), June 1970, 287–2944.

Some effects of water vapour on selenium rectifiers: H P D Lanyon, Phys Status Solidi (a), 2 (2), June 1970, 287–2944.

High Power Cockcroft-Walton Generator

To utilize the full current capability of the regular or symmetrical cascade generator, the conventional selenium rectifiers have to be replaced by a series-connection of silicon diodes which are rather sensitive to overvoltages and overcurrents. The problem of the application and protection of silicon diodes in high voltage generators had to be overcome in connection with the design of an air-insulated 770-kV dc power supply with a rated current of 180 mA dc for the ATOMIC ENERGY OF CANADA, LTD., Chalk River, Ontario and also for a 2 MV, 30 mA test facility.

Injection and thermal effects in selenium rectifiers undergoing reverse current flow

The change with time of the voltage drop across a selenium rectifier passing a constant current is studied. For high current densities a thermal relaxation mechanism is assumed and the thermophysical state is formulated for this case.

Measurement of selenium rectifiers at high current densities

Measurement of selenium rectifiers at high current densities

A contribution to the capacity measurements of selenium rectifiers

A contribution to the capacity measurements of selenium rectifiers

Prebreakdown condition in selenium rectifiers

This paper reports data from an experimental investigation of the prebreakdown and breakdown conditions of factory production selenium rectifiers in the temperature range from 100 ° to −196 ° C when a unit voltage pulse with steep leading edge (rise time about 10−8 sec) is applied to the rectifier in the non-conducting direction. Change in voltage across the rectifier and in current through it were recorded by a two-channel high-speed electronic oscilloscope. On the basis of this test data, the variation of discharge rise-time in the selenium p-n junction as a function of overvoltage and temperature was determined, the formation of current pulses was detected in the junction, both before and during breakdown in the temperature range from 100 ° to −196 ° C, and it was also established that breakdowns of selenium rectifier p-n junctions are due to joint action of the Zener effect and impact ionization.

Property of selenium rectifier as a high-frequency capacitor

A wide-band capacitor utilizing a backward-biased selenium rectifier is reported. The capacitor is capable of covering a wide baseband frequency from low frequency to several hundred megahertz, and the series resonant frequency of the element having a capacitance of 0.01 µF exists above 100 MHz.

Temperature dependence of the piezoelectric effect in selenium rectifier elements

Results are given for an investigation of the temperature dependence of the piezoelectric effect in selenium rectifier elements. A scheme is offered to explain the mechanism of this effect.

The Solid State

Modern semiconductor physics has developed from the quantum mechanical work on energy band theory of charge carriers in semiconductors associated with the name of A. H. Wilson and his classic papers on the subject, and also with the name of Schottky who pioneered the atomistic approach to disorder phenomena in solids. This work dates from about 1930 and theoretical developments up to the beginning of the War were relatively slow. Semiconductor technology in the same period was represented by a few devices only. These included the copper oxide and selenium rectifiers which were in use in certain equipment and in the process of further development. The silicon whisker detector was being used for the detection and measurement of microwave power. It will be recalled that silicon carbide and galena had been used as detectors of radio waves before the common usage of the thermionic valve. The development of radar during the War, which required semiconductor devices for detecting and mixing microwaves meant that considerable work was carried out on silicon, and parallel work on germanium meant that by the end of the War high‐back voltage rectifiers, using germanium, were available in developmental quantities. Problems of thermal detection meant that photo‐conductive and photo‐voltaic cells were developed for this purpose based on the materials thallium sulphide and lead sulphide. Attention was also focussed on electronic processes in ionic crystals in terms of improving display screens for cathode ray and similar tubes.

Beitrag zur Klärung des Grossen Flusswiderstandes von Selengleichrichtern

The differential resistance of selenium rectifiers in the linear part of the V–I characteristic in the forward direction is considered; its value is three orders of magnitude higher than that of monocrystalline Ge-or Si-rectifiers and is closely connected with the current carrying capacity of selenium rectifiers. X-ray pictures showing the crystalline structure of selenium layers after heat treatment of different duration show increasing crystal growth in the polycrystalline selenium layer so that the differential resistance should be reduced. Measurement of the differential resistance, however, showed a gradual increase following an initial decrease, which is obviously connected with the process of ageing.

RECTIFYING Te–Se–Cd STRUCTURES USING A SELENIUM SINGLE-CRYSTAL FILM

Rectifying Te–Se–Cd structures have been prepared in the laboratory using (101̄0) and (0001) selenium single-crystal films. In the forward direction the current density below 1 V follows the rectifier equation for a heterojunction and above 1 V it approaches a quadratic voltage dependence. In the latter voltage region a conventional selenium rectifier, however, shows a linear dependence.

Contribution to the study of the prebreakdown region of the selenium rectifiers

The behavior of current-voltage fluctuations in the prebreakdown region of the selenium rectifier is studied.