CA1175478A - Method of rectifying alternating current and apparatus for performing this method - Google Patents
Method of rectifying alternating current and apparatus for performing this methodInfo
- Publication number
- CA1175478A CA1175478A CA000374740A CA374740A CA1175478A CA 1175478 A CA1175478 A CA 1175478A CA 000374740 A CA000374740 A CA 000374740A CA 374740 A CA374740 A CA 374740A CA 1175478 A CA1175478 A CA 1175478A
- Authority
- CA
- Canada
- Prior art keywords
- working element
- current
- working
- semiconductor
- cooler
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 238000000034 method Methods 0.000 title claims abstract description 26
- 239000004065 semiconductor Substances 0.000 claims abstract description 28
- 230000037230 mobility Effects 0.000 claims abstract description 16
- 238000010438 heat treatment Methods 0.000 claims abstract description 13
- 239000000463 material Substances 0.000 claims abstract description 12
- 238000001816 cooling Methods 0.000 claims abstract description 5
- 241001098636 Trichogramma alpha Species 0.000 claims abstract 3
- 239000000969 carrier Substances 0.000 claims description 13
- 229910052732 germanium Inorganic materials 0.000 description 7
- GNPVGFCGXDBREM-UHFFFAOYSA-N germanium atom Chemical compound [Ge] GNPVGFCGXDBREM-UHFFFAOYSA-N 0.000 description 7
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 4
- 241001663154 Electron Species 0.000 description 4
- 239000010949 copper Substances 0.000 description 4
- 229910052802 copper Inorganic materials 0.000 description 4
- 239000000243 solution Substances 0.000 description 4
- 238000002347 injection Methods 0.000 description 3
- 239000007924 injection Substances 0.000 description 3
- 241001527902 Aratus Species 0.000 description 2
- 229910001245 Sb alloy Inorganic materials 0.000 description 2
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 2
- 239000002140 antimony alloy Substances 0.000 description 2
- 229940000425 combination drug Drugs 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000005265 energy consumption Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 229910052710 silicon Inorganic materials 0.000 description 2
- 239000010703 silicon Substances 0.000 description 2
- 241000894007 species Species 0.000 description 2
- 230000003245 working effect Effects 0.000 description 2
- 102100039527 CBP80/20-dependent translation initiation factor Human genes 0.000 description 1
- 101000746131 Homo sapiens CBP80/20-dependent translation initiation factor Proteins 0.000 description 1
- 241000557769 Iodes Species 0.000 description 1
- 230000002730 additional effect Effects 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 239000004411 aluminium Substances 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- 235000010210 aluminium Nutrition 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 150000001768 cations Chemical class 0.000 description 1
- 229910052729 chemical element Inorganic materials 0.000 description 1
- ANTSCNMPPGJYLG-UHFFFAOYSA-N chlordiazepoxide Chemical compound O=N=1CC(NC)=NC2=CC=C(Cl)C=C2C=1C1=CC=CC=C1 ANTSCNMPPGJYLG-UHFFFAOYSA-N 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000001276 controlling effect Effects 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- FGXWKSZFVQUSTL-UHFFFAOYSA-N domperidone Chemical compound C12=CC=CC=C2NC(=O)N1CCCN(CC1)CCC1N1C2=CC=C(Cl)C=C2NC1=O FGXWKSZFVQUSTL-UHFFFAOYSA-N 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000008030 elimination Effects 0.000 description 1
- 238000003379 elimination reaction Methods 0.000 description 1
- OYFJQPXVCSSHAI-QFPUQLAESA-N enalapril maleate Chemical compound OC(=O)\C=C/C(O)=O.C([C@@H](C(=O)OCC)N[C@@H](C)C(=O)N1[C@@H](CCC1)C(O)=O)CC1=CC=CC=C1 OYFJQPXVCSSHAI-QFPUQLAESA-N 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 230000006870 function Effects 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- WPYVAWXEWQSOGY-UHFFFAOYSA-N indium antimonide Chemical compound [Sb]#[In] WPYVAWXEWQSOGY-UHFFFAOYSA-N 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000010355 oscillation Effects 0.000 description 1
- QHGVXILFMXYDRS-UHFFFAOYSA-N pyraclofos Chemical compound C1=C(OP(=O)(OCC)SCCC)C=NN1C1=CC=C(Cl)C=C1 QHGVXILFMXYDRS-UHFFFAOYSA-N 0.000 description 1
- 229910000679 solder Inorganic materials 0.000 description 1
- 238000013519 translation Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L29/00—Semiconductor devices specially adapted for rectifying, amplifying, oscillating or switching and having potential barriers; Capacitors or resistors having potential barriers, e.g. a PN-junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof ; Multistep manufacturing processes therefor
- H01L29/02—Semiconductor bodies ; Multistep manufacturing processes therefor
- H01L29/36—Semiconductor bodies ; Multistep manufacturing processes therefor characterised by the concentration or distribution of impurities in the bulk material
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
- H01L2924/0001—Technical content checked by a classifier
- H01L2924/0002—Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
Landscapes
- Engineering & Computer Science (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Power Engineering (AREA)
- Physics & Mathematics (AREA)
- Ceramic Engineering (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- General Physics & Mathematics (AREA)
- Computer Hardware Design (AREA)
- Rectifiers (AREA)
- Nitrogen And Oxygen Or Sulfur-Condensed Heterocyclic Ring Systems (AREA)
- Cooling Or The Like Of Semiconductors Or Solid State Devices (AREA)
- Bipolar Transistors (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
Disclosure is made of a method of rectifying alter-nating current by providing a gradient of the ratio of the mobilities of the electrons and holes in a semiconductor with aid of a temperature gradient in which the temperature gradient and bipolar conductivity are provided by self-heating of the material of the semiconductor by the rectified current, in combination with cooling of a part of the material of the semiconductor, with the value of the exponent of the power (.alpha.) of the temperature (T) dependence of the ratio (b) of the mobilities of the electrons and holes /??T.alpha. / being not less than 0.1. The apparatus for performing the method, in accor-dance with the invention, comprises a semiconductor working element with nonrectifying contacts and a cooler adjoining this working element, with the dimensions of the semiconductor working element being selected to provide, in combination with the cooler within the working current range, non-uniform self-heating by the rectified current, with the gradient of the ratio of the mobilities of electrons and holes
Disclosure is made of a method of rectifying alter-nating current by providing a gradient of the ratio of the mobilities of the electrons and holes in a semiconductor with aid of a temperature gradient in which the temperature gradient and bipolar conductivity are provided by self-heating of the material of the semiconductor by the rectified current, in combination with cooling of a part of the material of the semiconductor, with the value of the exponent of the power (.alpha.) of the temperature (T) dependence of the ratio (b) of the mobilities of the electrons and holes /??T.alpha. / being not less than 0.1. The apparatus for performing the method, in accor-dance with the invention, comprises a semiconductor working element with nonrectifying contacts and a cooler adjoining this working element, with the dimensions of the semiconductor working element being selected to provide, in combination with the cooler within the working current range, non-uniform self-heating by the rectified current, with the gradient of the ratio of the mobilities of electrons and holes
Description
-~ 17~4~8 MET~()D /~):F R}~CTIF~II\TG ALq'~N ATI~G
CURRE~ All~) APPARA~I~US E`()E~ PERFO~
1~ G 'l`E[IS I~E ' C rTO D
The present inven-tion relates to electrical engi-neerin~ ancl semiconduc-tor devices, and more particularly it relates to methods o~ recti~ying al-ternatinF; curren-t an(l ~o apparatus capable of performing such methods~
~ he most advantageous ~ield o~ aPplications of the present invention is the provision o~ recti~iers for pow-er transmission.
For the purposes o~ convertin~, trans~rming and transmitting electric power o~ high power values over con-siderable distances there are required nowadays recti~i-ers capable o~ handling high voltages and ~reat current values. The industrially used diode or uncontrolled pow-er rec-tifiers and -th~ristors are limi-ted by the dimensions o~ the rectifying layers and the technology o~ t~eir fab-rication. It is there~ore desirable -to develop principal-ly novel recti~ier units and methods not based on a tech-nologically built-in recti~ying layer.
Known in the art are methods of recti~ying alter-nating current with aid o~ semiconductor diodes of vari-ous types, includin~ technologically built-in rectifying layers (cf. "The Fundamentals o~ Physics o~ Semiconduc-tor Devices" by Y.A. ~edo-tov; in Russian, Moscow1 "Soviet-skoe Radio" Publishers, 1970, pp. 1~8-139).
The known semiconductor or solici-state diodes are 175~7 rectifying elements comprising a recti~ying layer tech-nologicall~ built-in either witLin tlle body or on the su~face o~ tf.e serrllcon~uctor, having -two electric leads and an appropriate construction.
The small -thickness and insu~icient tecllnical ho-~llogeneity o~ the rec-tifying layer have been ~ound to a~-fect its electric stren~jth. On account of this, -the known devices would not withstand higrl voltages and great cur-ren-t density values. The theore-tical limit oi current density in case of germanium and silico~iodes with a recti~ying layer is assessed as 106 A/m2, which, however, would not be attained in practical cases. Furthermore, -the necessit~ oP using technologies of providing a recti-fying layer either within the body or o~khe surface o~
a semiconductor both complicates and rises the co~t of manufacture o~ alternating-current rectifiers.
~ nown in the art is a met~od o~ recti~ying elect-ric current in a semiconductor without a -technologically built-in rectifying layer. This method is based on creat-ing a concentration gradient in a semiconductor with aid o~ a temperature g~radient (c~. "Photo- and ~hermoelectric Phenomena in Semiconductors" by J. Tauts; Russian -trans-lation, Moscow, "~oreign Literature" Publishers, 1962, p ~
Accordin~ to the known method, a temperature gradi-ent is induced in a homo~eneous e~trinsic or impurity semi-oonduc-tor by means of a heater and a cooler arranged at 1 175'L78 the opposi-te ends of a specimen, so as -to ensure a gra-dien-t of the concentration of the majority current car-riers. With this tempera-ture graclient being su~ficient-ly sharp, so that the concen-tration o~ the majority cur~
rent carriers significa~l-tly varies over the diffusion bias length, non-equilibrium current carriers appear, and the curren-t is rec-tified.
However, this known method o~ recti~yin~ alternat-in~ current is characterized by a 10W efficiency fac~tor on account of the low recti~ication ~actor. For this rea-son the method has failed to fi~d practical applications.
A hi~her efficiency factor is o~ered b~ another known method o~ rectifying alter~ating current (c~ et-ter3 of Journal of Technical Physics~' by Kh.I. Amirkha-nov, E.~. Aliev, R.I~ Bashirov, ~.~1. Gadzhialiev, Vol. 4, p. 660, 1978~. According to the known method, a heater and a cooler arranged at the opposite ends of a germanium wa~er are used to provide a gradient of the ratio of the mobilities of electrons and holes longitudinally of the wa~er, thus creating a tel~perature gradient and bipolar conduction by heating one end of the g~ermanium wafe~ and cooling its opposite end. '~he bipolar conduction is ensur-ed b~ the heater -temperature.
However, even this method which we consider -to be the closest prior art OI' the presen-t invention is charac-terized by a relatively low efficiency factor, on account, ~ - ~
~ 175~78 among other things, of energy consumption by the heater.
Furthermore, an apparatus for performing this method is structurally complicated:by the necessity of matching the heater to the semiconductor, of providing heat insulation of the heater, of having connection wires and a power source for supplying the heater.
It is an object of the present inventiontoeliminate the abovementioned disadvantages of 'he method and to broaden the operational capabilities of the apparatus for performing same.
According to the present invention there is provided a method of rectifying alternating current by providing a gradient of the ratio of the mobilities of electrones and holes in a semiconductor with the aid of a temperature gradient, wherein the temperature gradient and the bipolar conductivity are provided by self-heating of the material of the semicon-ductor by the current being rectified in combination with cooling a part of the material of the semiconductor, the value of the exponent of the power (a) of the temperature (T) de-pendence of the ratio (b) of the mobilities of electrones and holes (b ~ Ta) being not less than 0.1.
'^':: ^
: .
~ 175478 The efficiency factor of the rectifying operation is thus enhanced both by eliminating the energy consumption by the heater and by the appearance of the square-law characteristic of the relationship between the rectification effect and the current density (the positive feedback rela-tionship between rectification and the current density).
~he range of semiconductor materials usable for rectification has been also broadened.
Furthermore, the object of the invention is attained in an apparatus for performing the above-specified method, comprising a semiconductor working element with non-rectifying contacts and a cooler adjoining the working element, in which apparatus, in accordance with the invention, the dimensions of the working element are selected to ensure, in combination with the action of the cooler within the range of the working currents, non-uniform self-heating by the current being rectified, with the gradient of the ratio of the mobilities of electrons and holes ( db ) not less than 0.2 cm 1, and bipolar conduction of the working element.
The invention simplifies the structure of the recti-fier and makes it less costly, owing to the elimination ~ - 5 -~ ~ 75~78 v:e the heater.
To ~roaden the operational ab.ilities of the appara-tus 9 i t iS e~pedient -to have the cooler movable longi-tu-dinally OI' the -working elemerlt.
This enables to solve a number of technical problems associa-ted wit.l rectiLication by con-trolling -the volt-am-pere chaLacteristic with aid OI displacing the cooler.
The invention will be further described in connec-tion witll e~lbodimen-ts thereoI, with re~erence beingJ had to the accompanJing drawings, wherein:
FIG. 1 illustrates sche~latically an apparatus eor per~oIming the method ol recti~ying electric current in accordanca with -the invention;
FIG. ~ is a circuit diagram of wiring the apparatus into an ~-lectric circuit, with hal~-wave recti~ication;
FIG. 3 is a modi~ication Oe the aPparatus ~or per~
~orming the ~ethod Oe recti~ying alternating current in ac-cordance with the invention;
FIG. 4 is a circuit diagram O~e wiring the apparatus into an electric circuit, with full-wave recti~ication;
~ IG. 5 is another modifica-tion of the apparatus ~or performing the method Oe rectifying alternating current in accordance with ttle inven-tion;
FIGo 6 is the apparatus shown in FIG. 5, with addi-tional contacts.
Re~erring now to the drawings, -the apparatus 1 ~or rectif~ing alternatin,, current, according to the invention, compriseS a workin~, element 2 (FIG. 1) made oI~ a semicon-1 17~478 ductor wi-th different -temperat~e der)endences of trhe rno-bility ol el ctrons and holts. The two opposite end faces o:f -tne working elemerlt 2 have connected thereto non-rect ifyin~ con-tac-ts 3 and 4 by which the a-,opara-tus 1 is con-nectable to an electric circuitO The end of' -the worhing element 2 provided ~-rith the contact 4 is adjoined by a cooler 5 which is ei-ther air- or water-cooled.
The dimensions of -the working element are selected in accordance with the loss inde~ ( Nl ~ of the rec-ti~ied current in the wor-king element 2, to provide the highest possible temperature gradient; Nl = IlVl wherein Il is tile current through the working element 2 and Vl is the voltage drop ac.ross the working element 2.
By ~irst a~proxima-tion, the dimensions of the work-ing element 2 can be compu-ted from the formula:
s = T1 ~1 e herein ~e is the heat conductivity factor of the mate-rial of' the working element 2;
T is the ternperature differential between the ends of the working elements 2 at the con-tacts 3 and 4;
1 is the length of the working element 2;
S is the cross-sec-tional area of the working element 2.
- .~
1 ~7547~
AccordinP -to t;~ie irlvention7 t;le value of the tem-perature ,radient ~I^ovl(l be at least 0-2~ '1' , where-in '~ iS the temperature, ~, arld "b" is -the ratio of the rnobilities o~ -the elec-trons and holes. In practical appli-ca-tions, it i6 expedient -to a-ttain the highest tempera-ture gradient possible, so as to step up the ef~iciency factor. ~he cooler ifi e~pected -to provide the ma~imum withdrawal ol the heat dissipated in -the working element 2.
In opera-tion, the apparatus 1 is wired into an al--ternating-current circuit ~ . 2) in series wi-th a load 6 and a resistor 7 -through a control transformer 8. '~he required value o~ -the rectified voltage is preset Wit~l the trans~ormer 8, and the requi1ed current value is pre-set with -the resistor 7. With the workin~ current and volt-age range at-tained and the cooler 5 turned on, the work-in~ element 2 (FIG. 1) heats up. The temperature of the hot portion of the working element 2 provides for bipolar (in-trinsic) conduction, with at least a part OI the volume of the therrnally non-uniform workin~ elemen-t 2 displaying this bipolar conduction, i.e. beinK filled with electrons and holes within a tempera-ture field. As the working ele-ment 2 is made of a material wi-th di~ferent temperature de~endences OI the mobilities of electrons and holes, there is set within trLe working element 2 alongside of the temperatllre gradien-t a gradient of the ratio ( d~
o~ t-he rnobilities of electrons and holes:
1 17547~
b = b('~ T~ _ = c T
~lerein ~e is the mobility OI' electrons~
p is the mobili-ty o~ holes, c is a num~;rical coe~ficient.
'I'his results in variation of the injection ( ~ ) factor lorjnitudinally o~ the working element 2, alongside oL the temperature gradient:
(X ) = -1 ~ p~ xherein n is the concentration of elec-trons J
p is -the concentration of holes.
~ or the area o~ intrinsic conduction, the injection factor is:
k, (X ) 1 _ 1~ g~X) With the current flowing through -the portions of the workin, element 2 with different values o~ the in-jection factor ( ~ ), non-equilibrium current carriers are either injected or e~tracted i~ accordance with the relative direc-tions of the temperature gradient ( dT
and c ~ rent density (j).
In case oi intrinsic conduction, the concentration o~ non-equilibrium holes (~ p ) is deter~Qined by the gra-dient o~ the ratio of the mobilities and the current den~
1 17547d ~i~y ~ /) 2 ~ f q is the charge o~ an electron;
is the lifetirne o~ non-equilibrium current carriers~
j is the current densit~.
db In -the method o~ the pIior art, dx is provided by the temperature gradient, with aid of the heater and the cooler. ~herefore, in the method o~ the prior art there is a linear relationship between recti~icatio~ and the current density.
In accordance with the invention, the gradient o~
the ratio of the mobilities ( db ) is provided by sel~
heating: _ @=c~g'~ = o~t In ~irst apProximat;ion:
V
X ~
wherei~ V i9 the voltage drop across the working eleme~t
CURRE~ All~) APPARA~I~US E`()E~ PERFO~
1~ G 'l`E[IS I~E ' C rTO D
The present inven-tion relates to electrical engi-neerin~ ancl semiconduc-tor devices, and more particularly it relates to methods o~ recti~ying al-ternatinF; curren-t an(l ~o apparatus capable of performing such methods~
~ he most advantageous ~ield o~ aPplications of the present invention is the provision o~ recti~iers for pow-er transmission.
For the purposes o~ convertin~, trans~rming and transmitting electric power o~ high power values over con-siderable distances there are required nowadays recti~i-ers capable o~ handling high voltages and ~reat current values. The industrially used diode or uncontrolled pow-er rec-tifiers and -th~ristors are limi-ted by the dimensions o~ the rectifying layers and the technology o~ t~eir fab-rication. It is there~ore desirable -to develop principal-ly novel recti~ier units and methods not based on a tech-nologically built-in recti~ying layer.
Known in the art are methods of recti~ying alter-nating current with aid o~ semiconductor diodes of vari-ous types, includin~ technologically built-in rectifying layers (cf. "The Fundamentals o~ Physics o~ Semiconduc-tor Devices" by Y.A. ~edo-tov; in Russian, Moscow1 "Soviet-skoe Radio" Publishers, 1970, pp. 1~8-139).
The known semiconductor or solici-state diodes are 175~7 rectifying elements comprising a recti~ying layer tech-nologicall~ built-in either witLin tlle body or on the su~face o~ tf.e serrllcon~uctor, having -two electric leads and an appropriate construction.
The small -thickness and insu~icient tecllnical ho-~llogeneity o~ the rec-tifying layer have been ~ound to a~-fect its electric stren~jth. On account of this, -the known devices would not withstand higrl voltages and great cur-ren-t density values. The theore-tical limit oi current density in case of germanium and silico~iodes with a recti~ying layer is assessed as 106 A/m2, which, however, would not be attained in practical cases. Furthermore, -the necessit~ oP using technologies of providing a recti-fying layer either within the body or o~khe surface o~
a semiconductor both complicates and rises the co~t of manufacture o~ alternating-current rectifiers.
~ nown in the art is a met~od o~ recti~ying elect-ric current in a semiconductor without a -technologically built-in rectifying layer. This method is based on creat-ing a concentration gradient in a semiconductor with aid o~ a temperature g~radient (c~. "Photo- and ~hermoelectric Phenomena in Semiconductors" by J. Tauts; Russian -trans-lation, Moscow, "~oreign Literature" Publishers, 1962, p ~
Accordin~ to the known method, a temperature gradi-ent is induced in a homo~eneous e~trinsic or impurity semi-oonduc-tor by means of a heater and a cooler arranged at 1 175'L78 the opposi-te ends of a specimen, so as -to ensure a gra-dien-t of the concentration of the majority current car-riers. With this tempera-ture graclient being su~ficient-ly sharp, so that the concen-tration o~ the majority cur~
rent carriers significa~l-tly varies over the diffusion bias length, non-equilibrium current carriers appear, and the curren-t is rec-tified.
However, this known method o~ recti~yin~ alternat-in~ current is characterized by a 10W efficiency fac~tor on account of the low recti~ication ~actor. For this rea-son the method has failed to fi~d practical applications.
A hi~her efficiency factor is o~ered b~ another known method o~ rectifying alter~ating current (c~ et-ter3 of Journal of Technical Physics~' by Kh.I. Amirkha-nov, E.~. Aliev, R.I~ Bashirov, ~.~1. Gadzhialiev, Vol. 4, p. 660, 1978~. According to the known method, a heater and a cooler arranged at the opposite ends of a germanium wa~er are used to provide a gradient of the ratio of the mobilities of electrons and holes longitudinally of the wa~er, thus creating a tel~perature gradient and bipolar conduction by heating one end of the g~ermanium wafe~ and cooling its opposite end. '~he bipolar conduction is ensur-ed b~ the heater -temperature.
However, even this method which we consider -to be the closest prior art OI' the presen-t invention is charac-terized by a relatively low efficiency factor, on account, ~ - ~
~ 175~78 among other things, of energy consumption by the heater.
Furthermore, an apparatus for performing this method is structurally complicated:by the necessity of matching the heater to the semiconductor, of providing heat insulation of the heater, of having connection wires and a power source for supplying the heater.
It is an object of the present inventiontoeliminate the abovementioned disadvantages of 'he method and to broaden the operational capabilities of the apparatus for performing same.
According to the present invention there is provided a method of rectifying alternating current by providing a gradient of the ratio of the mobilities of electrones and holes in a semiconductor with the aid of a temperature gradient, wherein the temperature gradient and the bipolar conductivity are provided by self-heating of the material of the semicon-ductor by the current being rectified in combination with cooling a part of the material of the semiconductor, the value of the exponent of the power (a) of the temperature (T) de-pendence of the ratio (b) of the mobilities of electrones and holes (b ~ Ta) being not less than 0.1.
'^':: ^
: .
~ 175478 The efficiency factor of the rectifying operation is thus enhanced both by eliminating the energy consumption by the heater and by the appearance of the square-law characteristic of the relationship between the rectification effect and the current density (the positive feedback rela-tionship between rectification and the current density).
~he range of semiconductor materials usable for rectification has been also broadened.
Furthermore, the object of the invention is attained in an apparatus for performing the above-specified method, comprising a semiconductor working element with non-rectifying contacts and a cooler adjoining the working element, in which apparatus, in accordance with the invention, the dimensions of the working element are selected to ensure, in combination with the action of the cooler within the range of the working currents, non-uniform self-heating by the current being rectified, with the gradient of the ratio of the mobilities of electrons and holes ( db ) not less than 0.2 cm 1, and bipolar conduction of the working element.
The invention simplifies the structure of the recti-fier and makes it less costly, owing to the elimination ~ - 5 -~ ~ 75~78 v:e the heater.
To ~roaden the operational ab.ilities of the appara-tus 9 i t iS e~pedient -to have the cooler movable longi-tu-dinally OI' the -working elemerlt.
This enables to solve a number of technical problems associa-ted wit.l rectiLication by con-trolling -the volt-am-pere chaLacteristic with aid OI displacing the cooler.
The invention will be further described in connec-tion witll e~lbodimen-ts thereoI, with re~erence beingJ had to the accompanJing drawings, wherein:
FIG. 1 illustrates sche~latically an apparatus eor per~oIming the method ol recti~ying electric current in accordanca with -the invention;
FIG. ~ is a circuit diagram of wiring the apparatus into an ~-lectric circuit, with hal~-wave recti~ication;
FIG. 3 is a modi~ication Oe the aPparatus ~or per~
~orming the ~ethod Oe recti~ying alternating current in ac-cordance with the invention;
FIG. 4 is a circuit diagram O~e wiring the apparatus into an electric circuit, with full-wave recti~ication;
~ IG. 5 is another modifica-tion of the apparatus ~or performing the method Oe rectifying alternating current in accordance with ttle inven-tion;
FIGo 6 is the apparatus shown in FIG. 5, with addi-tional contacts.
Re~erring now to the drawings, -the apparatus 1 ~or rectif~ing alternatin,, current, according to the invention, compriseS a workin~, element 2 (FIG. 1) made oI~ a semicon-1 17~478 ductor wi-th different -temperat~e der)endences of trhe rno-bility ol el ctrons and holts. The two opposite end faces o:f -tne working elemerlt 2 have connected thereto non-rect ifyin~ con-tac-ts 3 and 4 by which the a-,opara-tus 1 is con-nectable to an electric circuitO The end of' -the worhing element 2 provided ~-rith the contact 4 is adjoined by a cooler 5 which is ei-ther air- or water-cooled.
The dimensions of -the working element are selected in accordance with the loss inde~ ( Nl ~ of the rec-ti~ied current in the wor-king element 2, to provide the highest possible temperature gradient; Nl = IlVl wherein Il is tile current through the working element 2 and Vl is the voltage drop ac.ross the working element 2.
By ~irst a~proxima-tion, the dimensions of the work-ing element 2 can be compu-ted from the formula:
s = T1 ~1 e herein ~e is the heat conductivity factor of the mate-rial of' the working element 2;
T is the ternperature differential between the ends of the working elements 2 at the con-tacts 3 and 4;
1 is the length of the working element 2;
S is the cross-sec-tional area of the working element 2.
- .~
1 ~7547~
AccordinP -to t;~ie irlvention7 t;le value of the tem-perature ,radient ~I^ovl(l be at least 0-2~ '1' , where-in '~ iS the temperature, ~, arld "b" is -the ratio of the rnobilities o~ -the elec-trons and holes. In practical appli-ca-tions, it i6 expedient -to a-ttain the highest tempera-ture gradient possible, so as to step up the ef~iciency factor. ~he cooler ifi e~pected -to provide the ma~imum withdrawal ol the heat dissipated in -the working element 2.
In opera-tion, the apparatus 1 is wired into an al--ternating-current circuit ~ . 2) in series wi-th a load 6 and a resistor 7 -through a control transformer 8. '~he required value o~ -the rectified voltage is preset Wit~l the trans~ormer 8, and the requi1ed current value is pre-set with -the resistor 7. With the workin~ current and volt-age range at-tained and the cooler 5 turned on, the work-in~ element 2 (FIG. 1) heats up. The temperature of the hot portion of the working element 2 provides for bipolar (in-trinsic) conduction, with at least a part OI the volume of the therrnally non-uniform workin~ elemen-t 2 displaying this bipolar conduction, i.e. beinK filled with electrons and holes within a tempera-ture field. As the working ele-ment 2 is made of a material wi-th di~ferent temperature de~endences OI the mobilities of electrons and holes, there is set within trLe working element 2 alongside of the temperatllre gradien-t a gradient of the ratio ( d~
o~ t-he rnobilities of electrons and holes:
1 17547~
b = b('~ T~ _ = c T
~lerein ~e is the mobility OI' electrons~
p is the mobili-ty o~ holes, c is a num~;rical coe~ficient.
'I'his results in variation of the injection ( ~ ) factor lorjnitudinally o~ the working element 2, alongside oL the temperature gradient:
(X ) = -1 ~ p~ xherein n is the concentration of elec-trons J
p is -the concentration of holes.
~ or the area o~ intrinsic conduction, the injection factor is:
k, (X ) 1 _ 1~ g~X) With the current flowing through -the portions of the workin, element 2 with different values o~ the in-jection factor ( ~ ), non-equilibrium current carriers are either injected or e~tracted i~ accordance with the relative direc-tions of the temperature gradient ( dT
and c ~ rent density (j).
In case oi intrinsic conduction, the concentration o~ non-equilibrium holes (~ p ) is deter~Qined by the gra-dient o~ the ratio of the mobilities and the current den~
1 17547d ~i~y ~ /) 2 ~ f q is the charge o~ an electron;
is the lifetirne o~ non-equilibrium current carriers~
j is the current densit~.
db In -the method o~ the pIior art, dx is provided by the temperature gradient, with aid of the heater and the cooler. ~herefore, in the method o~ the prior art there is a linear relationship between recti~icatio~ and the current density.
In accordance with the invention, the gradient o~
the ratio of the mobilities ( db ) is provided by sel~
heating: _ @=c~g'~ = o~t In ~irst apProximat;ion:
V
X ~
wherei~ V i9 the voltage drop across the working eleme~t
2. There~ore, in acc~rdarlce with the invention, there is a square-law characteristic o~ the relationship between the concentration of non-equilibrium current carriers (~ ) and the culrent density: , ~
/) T
1 17~478 wherein ~ is the exponent of the power of the te~-perature dependence of the ratio of the mobilities of the electrons and holes;
j is the current density;
V is the voltage drop across the working element Z;
is the heat conductivity factor of the material of the working element 2;
q is the charge of an electron;
T is the temperature, ~K;
T iS the lifetime of non-equilibrium current carriers.
Designating ~ =~b the following is obtained:
T
ap= ~T _ (2) Multiplying both sides of the equation by Mp-q(b+l), one obtains:
~P ~p~q(b+l)=~lpq(~+l) j2 V ~ _ a~-q(b+1)2 (3) The left-hand side of this equation is the specific conductivity of the working element 2, due to non-equilibrium current carriers, i.e. Qp;~p-q(b-~l)= a-aO
where a is the general conductivity of the working element 2.
- j2v Deslgnatlng ~ -~ ~hen a-aO=~. - (4) Since a = jL, where L is the length of the working element 2, a quadratic equation with respect to j is obtained: 2 2 j V B -j + aO V = O (5) ~RL L
1 175~7~
The solution of that equation is 1 4 Q'B V
~-L
2B-V ~-L (6) In the passing direction j > O, V> O.
It is evident from this equation that the max-imum value of the voltage drop on the working element 2 is obtained when j has a single solution il at which the apparatus is turned on and rectifies for all j ~ jl.
In order to find the value of Vl it should be assumed that:
r_ _ ~ 4 ~-B V~3 = O
~Q.L2 (7) from which V~ 1/3 (8) 4aO
Then, from equation 6, taking equation (7) into account j = _ L
2B~V12 (9) Inserting the value of Vl from equation (8) into equation (9), it follows that:
Ll/3S 1 ~( ~ ) 1/3 , ~O /3 (10) where ~ is the heat conductivity factor of the working element 2, ~O is the specific intrinsic conduction of the working element 2, L is the length of the working element 2, S is the area of the cross section of the working element 2, -b (b+l)-T
¦~ - lla --` I 175d~
T iS the life time of the non-equ~librium cur-rent carriers, ~ e,~p is the mobility of electrons and holes re-spectively, b-~P
~ is the exponent in the relationship b (T ) ~T~, T is the average temperature of the working element 2, j= J
J is the intensity of the working current.
With the implementation of the disclosed solu-tion of the problem, there is attained positive feedback relationship between the current density and the concen-tration of injected çurrent carriers, whereby the rectifi-cation factor sharply rises, and the efficiency factor rises accordingly.
Where the directions of thecurrent and tempera-ture gradient coincide, there takes place injection ofnon-equilibrium current carriers from some portions of the working element 2 into others; the re~istance of the working ~ - llb -l 1~5~78 -12~
element 2 drops, and the apl~aratus 1 (FlG. 2) is conduc--tive.
The direction oi t.he -temperature p,radient in the worling element 2 (~IG. 1) does no-t depend on the cur-ren-t alrection aad is deterrlined by -the arrangement of the cooler 5 ralative -to -the end faces of the working ele-men-t 2. 'f'here~lore, during the successive hal:e wave peIiod the directions ol~ -the current and temperature gradient become opposite; there takes place extraction o~ non-equi-librium current carriers; the resistance O:e the working element 2 rises, and the apparatus 1 curbs down the cur-ren-t value.
It can be seen from -the above formula -that the value oî ~ p determining the rectification process is dependent on the parameter ~ . When selectinf^; -the semiconductor material, i-t is expedient to chose the material with -the hi~"hest possible value of ~ , with otherwise similar values o:~ other parameters ( ~~, æ, ~ ). Thus, germanium ( ~ = 0.~7) is ~nore suitable than silicon ( ~ = 0.3).
Semiconductors with the value of ~ short of 0.1 in the apparatus in accordance with the invention render it incompetitive wi-th known semiconductor diodes.
Let us consider embodiments of the aPParatU9 1 il-lustrated in FIG. 2, comprising a germanium workinr element 2. In case of gerl.uanium, wi-th current dissipa-ted by tha thermal oscillation oL -the cr~vstal lattice, the e~ponent l 175~78 -J~3-o~ the polier o the -tempera-ture de~endence oL' the mobi-ll~y ratio ol' el~,ctrons and holes i9 0.67 ( ~ = 0.~7).
The worLini, element 2 was made oi? hole conduction ger~aniu,illNith speci~ic resistarlce ~ = 40 Ohm.cm, sLiaped into a rec-tangular wa~er with dimensions 2.0 x 1.0 ~
x 1.0 mm. 1~10rl-recti~ying contacts 3 and 4 were made by in~usion oP indium-antimony alloy into the end ~aces of -the workin~ element 2. The cooler 5 had a copper casing and was water-cooled.
~ et us consi(ler examples oi' the per~ormance o~ the abovespeci~ied embodiment o~7 -the appara-tus 1.
Example 1.
Wi-th working curren-t I = 0.02 A, the selec-ted dimen-sions o~ the working element 2 provided, in combination with -the operation o~ the cooler 5, non-uni~orm sel~-heat-ing of the working element 2 with the value of the gradi-ent ddb = 0.2. The e~iciency factor was ~ = 10%.
The power rating was -N = 1.5 W.
~ xample 2.
With workin~, current 1 = 0.5 A, the selected dimen-sions o~' the working element 2 provided, in combination with the operation o~ the cooler 5, non-uni~orm sel~-heat-ing o~ the working element 2 with the value o~ the gradi-ent ddb = 2Ø ~he e~iciency factor was 7 = 50 %.
'The power rating was N = 7 W.
~ 175478 _lLl,._ Exarnple 3.
With working current I = 1.0 A, -the selected dimen-sions of' the working elemen-t 2 provided ? in combination with the operation o~ the cooler 5, non-uniform self'-heat-ing of .the working element 2 with the valu~, oI' the gradi en-t ddb = 2.5. The e~f'iciency factor was ~ = 90 %.The power ratinK was N = lGO W.
Exarnple 4.
With working current I = 4.0 A, the selec-ted dimen-sions o~ the working element 2 provided, in combina-tion wit~ the operation o~ the cvoler 5, non-unif'orm sel~-heat-ing of the ~orking element 2 with the value of' -the gradi-en-t ddb = 4.0~ Th~ ef'ficiency factor was ~ = 99%. The power ratinf~ was N = 2 kW.
Let us consider an ernbodiment of' the apparatus 1 il-lustrated in ~IG. 1 with the worLing element 2 made oi si-licon. In case of' silicon the exponent of the power o~ the temperature dependence of' the mobility ratio of' electrons and holes is 0.3 ( ~ = 0.3).
The working elemen-t 2 was made of' hole conduction si-licon with the specific resistance ~ = 1200 Ohm.cm, shap-ed as a rectangular wafer with dimensions 4.0xl.0~1.0 mm.
~on-recti~ying contacts 3 and 4 were made by inf'using alu-minium into the end f'aces of' the working element 2. The working element 2 was soldered to -the cooler 5 witn aid o~
~, ,~ , --= ~
1 175~7~1 a speci~ic solder. T~e cooler 5 had a copper wa-teI-cooled casing.
Let us consider e~amples of the performance o~ the apparatus 1 ;Jith the si,licon working element 2.
hxalilp].e 1.
~ 'Jith working current I = 1.4 A, -the selected di-mensions OL the workin~ element 2 provided in cornbi~ation with t~le operation oi' the cooler 5, non-uni~orm sell'-heat-in~ o~ the working, element 2 with -the value o~ the gradi-ent db = 1.1. The e~iciency factor was ~ = 75 ~0. The power ratin,~ was N = 500 K~.
Example 2.
~ ith working current I = 1.5 A, -the selected dimen-sions o~ the working element 2 provided, in combination with the operation o~ the cooler 5, non-uni~orm sel~-heat-ing o~ the workin~ element 2 with -the value o~ the gradi-ent -dd~ = 1.23. The e~ficiency f`actor was ~ = 78 %.
The power rating was N - 600 W.
Example 3.
l~ith working current I = 1.8 A, -the selected dimen-sions of' the working elemen-t 2 in combina-tion with the operation of' the cooler 5 provided self-hea-ting o~ the vrorking element 2 with the value of` the gradient d- =
= 1.25. The ef'f'iciency f7actor was ~ = 82 % . The power ratin~, was li = 650 W.
1 175~L78 Th~ apparatus 1 (l'IG. 1) wired in-to the circuit illustrated in FIG. 2 passes c~rren-t durin~?; one half-wave period~ i.e. per~orms hal~-v~ave recti~cation.
The use both h,llf-waves of alternatin~j c~ rent, there can be emp]oyed a modi~ication 9 O:e the appara-tus, illust-rated in FIG. 3, wired into the circui;t illustrated in ~'IG. 4. The ap~aratus ~ (FIG. 3) is a modi~ication oY t~le apparatus 1 (FIG. 1), wherein the workin~ member 10 (FIG.3) iS U-shaPed, with three non-rectieyirlr, contacts. The cold contact 11 is connected to a central point o~ the trans-~ormer 8 (FIG. 4). The hot contacts 12 and 13 (~IG. 3) are connected to the terminal points o~ the trans~ormer 8 (FIG. 4). In -this modieica-tion, the apparatus 9 wired into the circuit il]ustrated in FIG. 4 provides full-wave recti-~ication o~" alternating current.
Let us con~ider an embodiment o~ the apparatus 9.
The wor'~in~ element 10 (FIG. 3) was made OI' hole conduc-tion germanium wi-th speciI'ic resistance ~ = 40 Ohm.cm. The two le~s O:e the U-shar~ed workin~ element 10 had the common base. Theldimensions OI' each leg were 2.0 x 1,0 x 1.0 mm.
The base dimensions were 2.~ ~ 1.0 x 0.2 mm.
The working element 10 had three non-rectieying con-tacts 11, 12 and 13 made by iniusion of' an indiu~-antimorly alloy into the common end ~ace oiJ the working element 10 (contact 11) and into the end ~aces of both le~js ~contacts 12 and 13). The working element 10 was soldered to the t7547 cooler 14 at the side o~ the common end face. I`he cooler 14 had a ~!ater-cooled copper casi.n~. The per~ormance o~
the apparatus 9 was p~actically -the same as that illus-t-rated in the above e~amples O:e the per~ormance of the ap-paratus 1 (FIG. 1) ~ith the working elernen-t 2 made o~ ger-manium.
To extend -the operational capabilities oI' the appa-ratus in accordance with the present invention, it is expe-dien-t to raake the cooler 15 (FIG. 5) adjus-table longi-tu-dinally of -the working element 16, to arrange a non-recti-~ying con-tact 17 centrally of the worKin~ element 16 and to provide non~rectifying contacts 18 and 19 at tne oppo-site ends o~ the working element 16. I~ the cooler 15 is adjusted to adjoin one of -t~e ends o- -the working element 16, the apparatus can be wired into a circuit via the con-tacts 18 and 19, -to rectify al-terna-ting cur.rent similarly to the apparatus 1 (FIG. 1).
With -the cooler 1~ adjusted centrally of the working element 16, as it is shown in FIG. 5, the apparatus func-tions as two apparatus 1 of the first~described embodiment, connected in series in the non-conducting direction. With this arrangement o~ tne cooler 15 the resistance o~ the apparatus is at the maximum, and it curbs down the current in the circui-t ~or either half-wave of tne alternating-current voltage. I~, on t~le other hand, the contacts 18 and 19 (FIG. 6) are interconnected into a common lead, the wiring o~ the apparatus into a c~rent vie either the con-tacts 17 and l& or tne contacts 17 and 19 would result in the apparatlls ~)resenting the minirnurn resistance to al-ter-nating current, since each hall~ o~ the apparatu~ would pass one hal~-~ave o~ the al-ternating current voltage.
Let us consider an embodimen~t o~ the apparatus il-lustrated in FIGS 5 and 6.
'~he -~orking elernent 16 was made o~ germanium with specific resistance ~ = 40 Ohm.cm, shaDed as a cylinder 5 mm in diameter, 5 cm lor~. Non-recti~ying con-tacts 17, 18 and 19 o~ an indiurn-antimony alloy were in~used, res-pectively, at -the centre and ends o~ the workin~ element 16.
The cooler 15 was made o~ copper ~or air-cooling, ~or adjustment longitudinally of the working element 16.
Int~mate contact o~ the cooler 15 with the body o~ -the working element 16 was insured, ~vith the cooler being 5 mm thick and having a ribbed e~ternal surface.
'~he implemen-tation o:E ~the disclosed solution o~ the technical problet~ enables to step up the ef~iciency fac-tor o~ rectifiers devoid o~ a technologicall~ built-in recti-~ying layer, si~llpli~ies the struc-ture o~ semiconduc-tor power rectiEiers and reduces -their costi it also enables to recti~y hi~3her voltages and greater currents and to control -the current value in a circuit.
/) T
1 17~478 wherein ~ is the exponent of the power of the te~-perature dependence of the ratio of the mobilities of the electrons and holes;
j is the current density;
V is the voltage drop across the working element Z;
is the heat conductivity factor of the material of the working element 2;
q is the charge of an electron;
T is the temperature, ~K;
T iS the lifetime of non-equilibrium current carriers.
Designating ~ =~b the following is obtained:
T
ap= ~T _ (2) Multiplying both sides of the equation by Mp-q(b+l), one obtains:
~P ~p~q(b+l)=~lpq(~+l) j2 V ~ _ a~-q(b+1)2 (3) The left-hand side of this equation is the specific conductivity of the working element 2, due to non-equilibrium current carriers, i.e. Qp;~p-q(b-~l)= a-aO
where a is the general conductivity of the working element 2.
- j2v Deslgnatlng ~ -~ ~hen a-aO=~. - (4) Since a = jL, where L is the length of the working element 2, a quadratic equation with respect to j is obtained: 2 2 j V B -j + aO V = O (5) ~RL L
1 175~7~
The solution of that equation is 1 4 Q'B V
~-L
2B-V ~-L (6) In the passing direction j > O, V> O.
It is evident from this equation that the max-imum value of the voltage drop on the working element 2 is obtained when j has a single solution il at which the apparatus is turned on and rectifies for all j ~ jl.
In order to find the value of Vl it should be assumed that:
r_ _ ~ 4 ~-B V~3 = O
~Q.L2 (7) from which V~ 1/3 (8) 4aO
Then, from equation 6, taking equation (7) into account j = _ L
2B~V12 (9) Inserting the value of Vl from equation (8) into equation (9), it follows that:
Ll/3S 1 ~( ~ ) 1/3 , ~O /3 (10) where ~ is the heat conductivity factor of the working element 2, ~O is the specific intrinsic conduction of the working element 2, L is the length of the working element 2, S is the area of the cross section of the working element 2, -b (b+l)-T
¦~ - lla --` I 175d~
T iS the life time of the non-equ~librium cur-rent carriers, ~ e,~p is the mobility of electrons and holes re-spectively, b-~P
~ is the exponent in the relationship b (T ) ~T~, T is the average temperature of the working element 2, j= J
J is the intensity of the working current.
With the implementation of the disclosed solu-tion of the problem, there is attained positive feedback relationship between the current density and the concen-tration of injected çurrent carriers, whereby the rectifi-cation factor sharply rises, and the efficiency factor rises accordingly.
Where the directions of thecurrent and tempera-ture gradient coincide, there takes place injection ofnon-equilibrium current carriers from some portions of the working element 2 into others; the re~istance of the working ~ - llb -l 1~5~78 -12~
element 2 drops, and the apl~aratus 1 (FlG. 2) is conduc--tive.
The direction oi t.he -temperature p,radient in the worling element 2 (~IG. 1) does no-t depend on the cur-ren-t alrection aad is deterrlined by -the arrangement of the cooler 5 ralative -to -the end faces of the working ele-men-t 2. 'f'here~lore, during the successive hal:e wave peIiod the directions ol~ -the current and temperature gradient become opposite; there takes place extraction o~ non-equi-librium current carriers; the resistance O:e the working element 2 rises, and the apparatus 1 curbs down the cur-ren-t value.
It can be seen from -the above formula -that the value oî ~ p determining the rectification process is dependent on the parameter ~ . When selectinf^; -the semiconductor material, i-t is expedient to chose the material with -the hi~"hest possible value of ~ , with otherwise similar values o:~ other parameters ( ~~, æ, ~ ). Thus, germanium ( ~ = 0.~7) is ~nore suitable than silicon ( ~ = 0.3).
Semiconductors with the value of ~ short of 0.1 in the apparatus in accordance with the invention render it incompetitive wi-th known semiconductor diodes.
Let us consider embodiments of the aPParatU9 1 il-lustrated in FIG. 2, comprising a germanium workinr element 2. In case of gerl.uanium, wi-th current dissipa-ted by tha thermal oscillation oL -the cr~vstal lattice, the e~ponent l 175~78 -J~3-o~ the polier o the -tempera-ture de~endence oL' the mobi-ll~y ratio ol' el~,ctrons and holes i9 0.67 ( ~ = 0.~7).
The worLini, element 2 was made oi? hole conduction ger~aniu,illNith speci~ic resistarlce ~ = 40 Ohm.cm, sLiaped into a rec-tangular wa~er with dimensions 2.0 x 1.0 ~
x 1.0 mm. 1~10rl-recti~ying contacts 3 and 4 were made by in~usion oP indium-antimony alloy into the end ~aces of -the workin~ element 2. The cooler 5 had a copper casing and was water-cooled.
~ et us consi(ler examples oi' the per~ormance o~ the abovespeci~ied embodiment o~7 -the appara-tus 1.
Example 1.
Wi-th working curren-t I = 0.02 A, the selec-ted dimen-sions o~ the working element 2 provided, in combination with -the operation o~ the cooler 5, non-uni~orm sel~-heat-ing of the working element 2 with the value of the gradi-ent ddb = 0.2. The e~iciency factor was ~ = 10%.
The power rating was -N = 1.5 W.
~ xample 2.
With workin~, current 1 = 0.5 A, the selected dimen-sions o~' the working element 2 provided, in combination with the operation o~ the cooler 5, non-uni~orm sel~-heat-ing o~ the working element 2 with the value o~ the gradi-ent ddb = 2Ø ~he e~iciency factor was 7 = 50 %.
'The power rating was N = 7 W.
~ 175478 _lLl,._ Exarnple 3.
With working current I = 1.0 A, -the selected dimen-sions of' the working elemen-t 2 provided ? in combination with the operation o~ the cooler 5, non-uniform self'-heat-ing of .the working element 2 with the valu~, oI' the gradi en-t ddb = 2.5. The e~f'iciency factor was ~ = 90 %.The power ratinK was N = lGO W.
Exarnple 4.
With working current I = 4.0 A, the selec-ted dimen-sions o~ the working element 2 provided, in combina-tion wit~ the operation o~ the cvoler 5, non-unif'orm sel~-heat-ing of the ~orking element 2 with the value of' -the gradi-en-t ddb = 4.0~ Th~ ef'ficiency factor was ~ = 99%. The power ratinf~ was N = 2 kW.
Let us consider an ernbodiment of' the apparatus 1 il-lustrated in ~IG. 1 with the worLing element 2 made oi si-licon. In case of' silicon the exponent of the power o~ the temperature dependence of' the mobility ratio of' electrons and holes is 0.3 ( ~ = 0.3).
The working elemen-t 2 was made of' hole conduction si-licon with the specific resistance ~ = 1200 Ohm.cm, shap-ed as a rectangular wafer with dimensions 4.0xl.0~1.0 mm.
~on-recti~ying contacts 3 and 4 were made by inf'using alu-minium into the end f'aces of' the working element 2. The working element 2 was soldered to -the cooler 5 witn aid o~
~, ,~ , --= ~
1 175~7~1 a speci~ic solder. T~e cooler 5 had a copper wa-teI-cooled casing.
Let us consider e~amples of the performance o~ the apparatus 1 ;Jith the si,licon working element 2.
hxalilp].e 1.
~ 'Jith working current I = 1.4 A, -the selected di-mensions OL the workin~ element 2 provided in cornbi~ation with t~le operation oi' the cooler 5, non-uni~orm sell'-heat-in~ o~ the working, element 2 with -the value o~ the gradi-ent db = 1.1. The e~iciency factor was ~ = 75 ~0. The power ratin,~ was N = 500 K~.
Example 2.
~ ith working current I = 1.5 A, -the selected dimen-sions o~ the working element 2 provided, in combination with the operation o~ the cooler 5, non-uni~orm sel~-heat-ing o~ the workin~ element 2 with -the value o~ the gradi-ent -dd~ = 1.23. The e~ficiency f`actor was ~ = 78 %.
The power rating was N - 600 W.
Example 3.
l~ith working current I = 1.8 A, -the selected dimen-sions of' the working elemen-t 2 in combina-tion with the operation of' the cooler 5 provided self-hea-ting o~ the vrorking element 2 with the value of` the gradient d- =
= 1.25. The ef'f'iciency f7actor was ~ = 82 % . The power ratin~, was li = 650 W.
1 175~L78 Th~ apparatus 1 (l'IG. 1) wired in-to the circuit illustrated in FIG. 2 passes c~rren-t durin~?; one half-wave period~ i.e. per~orms hal~-v~ave recti~cation.
The use both h,llf-waves of alternatin~j c~ rent, there can be emp]oyed a modi~ication 9 O:e the appara-tus, illust-rated in FIG. 3, wired into the circui;t illustrated in ~'IG. 4. The ap~aratus ~ (FIG. 3) is a modi~ication oY t~le apparatus 1 (FIG. 1), wherein the workin~ member 10 (FIG.3) iS U-shaPed, with three non-rectieyirlr, contacts. The cold contact 11 is connected to a central point o~ the trans-~ormer 8 (FIG. 4). The hot contacts 12 and 13 (~IG. 3) are connected to the terminal points o~ the trans~ormer 8 (FIG. 4). In -this modieica-tion, the apparatus 9 wired into the circuit il]ustrated in FIG. 4 provides full-wave recti-~ication o~" alternating current.
Let us con~ider an embodiment o~ the apparatus 9.
The wor'~in~ element 10 (FIG. 3) was made OI' hole conduc-tion germanium wi-th speciI'ic resistance ~ = 40 Ohm.cm. The two le~s O:e the U-shar~ed workin~ element 10 had the common base. Theldimensions OI' each leg were 2.0 x 1,0 x 1.0 mm.
The base dimensions were 2.~ ~ 1.0 x 0.2 mm.
The working element 10 had three non-rectieying con-tacts 11, 12 and 13 made by iniusion of' an indiu~-antimorly alloy into the common end ~ace oiJ the working element 10 (contact 11) and into the end ~aces of both le~js ~contacts 12 and 13). The working element 10 was soldered to the t7547 cooler 14 at the side o~ the common end face. I`he cooler 14 had a ~!ater-cooled copper casi.n~. The per~ormance o~
the apparatus 9 was p~actically -the same as that illus-t-rated in the above e~amples O:e the per~ormance of the ap-paratus 1 (FIG. 1) ~ith the working elernen-t 2 made o~ ger-manium.
To extend -the operational capabilities oI' the appa-ratus in accordance with the present invention, it is expe-dien-t to raake the cooler 15 (FIG. 5) adjus-table longi-tu-dinally of -the working element 16, to arrange a non-recti-~ying con-tact 17 centrally of the worKin~ element 16 and to provide non~rectifying contacts 18 and 19 at tne oppo-site ends o~ the working element 16. I~ the cooler 15 is adjusted to adjoin one of -t~e ends o- -the working element 16, the apparatus can be wired into a circuit via the con-tacts 18 and 19, -to rectify al-terna-ting cur.rent similarly to the apparatus 1 (FIG. 1).
With -the cooler 1~ adjusted centrally of the working element 16, as it is shown in FIG. 5, the apparatus func-tions as two apparatus 1 of the first~described embodiment, connected in series in the non-conducting direction. With this arrangement o~ tne cooler 15 the resistance o~ the apparatus is at the maximum, and it curbs down the current in the circui-t ~or either half-wave of tne alternating-current voltage. I~, on t~le other hand, the contacts 18 and 19 (FIG. 6) are interconnected into a common lead, the wiring o~ the apparatus into a c~rent vie either the con-tacts 17 and l& or tne contacts 17 and 19 would result in the apparatlls ~)resenting the minirnurn resistance to al-ter-nating current, since each hall~ o~ the apparatu~ would pass one hal~-~ave o~ the al-ternating current voltage.
Let us consider an embodimen~t o~ the apparatus il-lustrated in FIGS 5 and 6.
'~he -~orking elernent 16 was made o~ germanium with specific resistance ~ = 40 Ohm.cm, shaDed as a cylinder 5 mm in diameter, 5 cm lor~. Non-recti~ying con-tacts 17, 18 and 19 o~ an indiurn-antimony alloy were in~used, res-pectively, at -the centre and ends o~ the workin~ element 16.
The cooler 15 was made o~ copper ~or air-cooling, ~or adjustment longitudinally of the working element 16.
Int~mate contact o~ the cooler 15 with the body o~ -the working element 16 was insured, ~vith the cooler being 5 mm thick and having a ribbed e~ternal surface.
'~he implemen-tation o:E ~the disclosed solution o~ the technical problet~ enables to step up the ef~iciency fac-tor o~ rectifiers devoid o~ a technologicall~ built-in recti-~ying layer, si~llpli~ies the struc-ture o~ semiconduc-tor power rectiEiers and reduces -their costi it also enables to recti~y hi~3her voltages and greater currents and to control -the current value in a circuit.
Claims (3)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A method of rectifying alternating cur-rent by providing a gradient of the ratio of the mobil-ities of electrons and holes in a semiconductor with the aid of a temperature gradient, wherein the temperature gradient and the bipolar conductivity are provided by self-heating of the material of the semiconductor by the current being rectified in combination with cooling a part of the material of the semiconductor, the value of the exponent of the power (.alpha.) of the temperature (T) dependence of the ratio (b) of the mobilities of electrons and holes (b ? T.alpha.) being not less than 0.1.
2. An apparatus for performing the method of rectifying alternating current as claimed in claim 1, comprising a semiconductor working element with non-rectifying contacts and a cooler adjoining the working element, wherein the dimensions of the semi-conductor working element are selected such that the relationship is satisfied, wherein L is the length of the working element, S is the area of the cross-section of said working element, .sigma.0 is intrinsic conductivity of the working element, ? is the heat conductivity factor of the working element, J is the working current strength, µe, µp are the mobility of electrons and holes, ? is the lifetime of non-equilibrium current carriers, T is an average temperature of the working elements, .alpha. is the exponent of power of the dependence b (T) ~ T.alpha. .
3. An apparatus as claimed in claim 2, wherein the cooler is adapted for movement along the working element.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PCT/SU1981/000017 WO1982002982A1 (en) | 1981-02-23 | 1981-02-23 | Method and device for rectification of alternating current |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1175478A true CA1175478A (en) | 1984-10-02 |
Family
ID=21616720
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000374740A Expired CA1175478A (en) | 1981-02-23 | 1981-04-06 | Method of rectifying alternating current and apparatus for performing this method |
Country Status (7)
| Country | Link |
|---|---|
| JP (1) | JPS58500582A (en) |
| CA (1) | CA1175478A (en) |
| CH (1) | CH662445A5 (en) |
| DE (1) | DE3152734C2 (en) |
| GB (1) | GB2107520B (en) |
| SE (1) | SE445693B (en) |
| WO (1) | WO1982002982A1 (en) |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1049400B (en) * | 1959-01-29 | The Lummus Company, New York, N. Y. (V. St. A.) | Process for the production of granulated phosphate fertilizers |
-
1981
- 1981-02-23 GB GB08229669A patent/GB2107520B/en not_active Expired
- 1981-02-23 JP JP50123481A patent/JPS58500582A/en active Pending
- 1981-02-23 CH CH6145/82A patent/CH662445A5/en not_active IP Right Cessation
- 1981-02-23 DE DE3152734T patent/DE3152734C2/en not_active Expired
- 1981-02-23 WO PCT/SU1981/000017 patent/WO1982002982A1/en active Application Filing
- 1981-04-06 CA CA000374740A patent/CA1175478A/en not_active Expired
-
1982
- 1982-10-14 SE SE8205848A patent/SE445693B/en not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| DE3152734T1 (en) | 1983-02-24 |
| SE8205848D0 (en) | 1982-10-14 |
| CH662445A5 (en) | 1987-09-30 |
| GB2107520A (en) | 1983-04-27 |
| SE8205848L (en) | 1982-10-14 |
| SE445693B (en) | 1986-07-07 |
| DE3152734C2 (en) | 1985-09-05 |
| GB2107520B (en) | 1985-04-24 |
| JPS58500582A (en) | 1983-04-14 |
| WO1982002982A1 (en) | 1982-09-02 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Trivedi et al. | Performance evaluation of high-power wide band-gap semiconductor rectifiers | |
| Singh et al. | SiC power Schottky and PiN diodes | |
| Slack et al. | The maximum possible conversion efficiency of silicon‐germanium thermoelectric generators | |
| Adler | Accurate calculations of the forward drop and power dissipation in thyristors | |
| Treu et al. | Reliability of SiC power devices and its influence on their commercialization-review, status, and remaining issues | |
| Singh et al. | Large area, ultra-high voltage 4H-SiC pin rectifiers | |
| Khemka et al. | Characterization of phosphorus implantation in 4H-SiC | |
| Lades et al. | Dynamics of incomplete ionized dopants and their impact on 4H/6H-SiC devices | |
| Baptista et al. | High temperature characterization of electrical barriers in ZnO varistors | |
| US2928162A (en) | Junction type semiconductor device having improved heat dissipating characteristics | |
| CA1175478A (en) | Method of rectifying alternating current and apparatus for performing this method | |
| Fedison et al. | Electrical characteristics of 4.5 kV implanted anode 4H-SiC pin junction rectifiers | |
| Leung et al. | Heating mechanisms of LDMOS and LIGBT in ultrathin SOI | |
| Rai-Choudhury et al. | Electron irradiation induced recombination centers in silicon-minority carrier lifetime control | |
| Chudobiak | The saturation characteristics of np-ν-n power transistors | |
| US3519894A (en) | Low temperature voltage limiter | |
| US3369207A (en) | Temperature varied semiconductor device | |
| Pelaz et al. | The Poole-Frenkel effect in 6H-SiC diode characteristics | |
| Kinman et al. | Germanium and silicon power rectifiers | |
| Henkels | Germanium and silicon rectifiers | |
| Christou | Electro‐thermomigration in Al/Si, Au/Si interdigitized test structures | |
| Nallet et al. | Electrical and electrothermal 2D simulations of a 4H-SiC high voltage current limiting device for serial protection applications | |
| GB1599500A (en) | Solid state current limiter | |
| Kashiwa et al. | Comparative study on short-circuit and surge current capabilities of 1.2 kV SiC SBD-embedded MOSFETs | |
| Baliga et al. | Schottky rectifiers |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry | ||
| MKEX | Expiry |
Effective date: 20011002 |