CN101442079A - Photovoltaic power converter - Google Patents

Photovoltaic power converter Download PDF

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Publication number
CN101442079A
CN101442079A CN 200710301931 CN200710301931A CN101442079A CN 101442079 A CN101442079 A CN 101442079A CN 200710301931 CN200710301931 CN 200710301931 CN 200710301931 A CN200710301931 A CN 200710301931A CN 101442079 A CN101442079 A CN 101442079A
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layer
semi
power converter
photovoltaic power
emitter
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简·古斯塔夫·威尔森
刘强
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Flex Products Inc
Viavi Solutions Inc
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Flex Products Inc
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    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/50—Photovoltaic [PV] energy

Abstract

The invention provides a photovoltaic power converter which comprises a substrate, a first multilayered structure supported by the substrate, and a first current barrier layer. The first multilayered structure comprises: a first base layer of semiconductor material of a first conduction type; a first emitter layer of semiconductor material of a second conduction type; and a first conducting layer of semiconductor material of the second conduction type. The first conduction type is opposite to the second conduction type, so that a first junction area is formed between the first emitter layer and the first base layer. The first current barrier layer is manufactured by the semiconductor material of the second conduction type. The first current barrier layer is between the substrate and the first multilayered structure. The emitter layer is doped with carbon.

Description

Photovoltaic power converter
Cross reference to related application
[1] the present invention advocates in the U.S. Provisional Patent Application No.60/871 of submission on December 20th, 2006,108, name be called " be used for long-distance power delivery (〉〉1 kilometer) InP base photovoltaic power converter " priority and the U.S. Provisional Patent Application No.60/871 that submits on December 20th, 2006,125, name is called the priority of " photovoltaic power converter that is used for the novel Ultra-High Efficiency of long-distance power delivery ", by reference its content is incorporated among the application.
Technical field
[2] present invention relates in general to luminous power is transformed into the device of electrical power, especially, relate to the sectional type optical semiconductor power conversion device that contains current barrier layer.
Background of invention
[3] all having use that luminous power is transformed into the device of electrical power in many application, known to the public may be that sunlight is transformed into electric energy the most wherein, wherein generally uses silicon based opto-electronics battery (being also referred to as photocell or solar cell).In this class is used, the general photoelectric cell array that uses with big relatively photosensitive region.
[4] in this class was used, luminous power can be provided by high power laser light, and by optical fiber described luminous power is sent in the described module, and wherein, optical power signals is converted into electrical power signal.In this class was used, described light generally entered with the form of the limited infrared beam of high density, and corresponding to the low absorbing window of typical optical fiber, the wavelength of described light beam is generally in the scope of 900nm-1600nm.Luminous power transducer in this class is used has relatively little photosensitive region, preferred employing several square millimeters or littler circular photosensitive region, and described luminous power transducer is based on composite semiconductor, and described composite semiconductor (as InP, GaAs and their alloy) is more suitable for absorbing infrared light than silicon.This class is open in the United States Patent (USP) 5,342,45 that licenses to Virshup based on an example of the device of GaAs, it is incorporated among the application by reference at this
[5] as described in the patent document and present specification accompanying drawing 1 (reproduction of patent document Fig. 2 that this accompanying drawing 1 is Virshup) of Virshup, typical optical semiconductor power converter contains p-n junction 20, described p-n junction 20 is formed between base layer 16 and the emitter layer 18, described base layer 16 can be typical n utmost point layer, and described emitter layer 18 can be typical p utmost point layer.Described base layer 16 and emitter layer 18 are sandwiched between the high conductivity resilient coating 14 and high conductivity optical lens window layer 22 that is placed on the dielectric substrate 12, can add thicker conductive layer 24 after described optical lens window layer 22.Protective layer (Fig. 1 does not show) is positioned on the window layer, and as the metal gate ruling electrically contact head (Fig. 1 does not show) be deposited over as described on the protective layer.Protective layer is removed in (typical as 3 microns narrow gridlines) etching between described metal gate ruling, makes incident light can pass the window layer and is absorbed by following p-n junction 20.In order to finish circuit, generally also to erode to the n district of p-n junction by etching technique.Etch depth is generally several microns to guarantee to arrive base layer 16.In case when metal is deposited over the n utmost point layer that comes out, just can between the n utmost point and the p utmost point, connect.When absorbing when photon incident and by p-n junction 20, produce charge carrier, and produce at p-n junction under the condition of electric field, described carrier mobility also is collected to produce electrical potential difference betwixt at the electric contactor place.By connecting external circuit, just can extract electrical power.
[6] the single p-n junction open circuit voltage that can transmit is subject to the forbidden band of the semi-conducting material that is adopted, and the described voltage that transmits is generally less than 1 volt.By the form with transversary a plurality of described p-n junctions are connected, each voltage is added up just can produce the output voltage that meets or exceeds 12 volts.In order to make the single p-n junction element of this class, generally carry out etching at adjacent minute interblock.Described etching must be enough dark so that these p-n junctions are isolated from each other, and the typical degree of depth is about 25 microns.In order to finish the series connection of p-n junction, between adjacent p-n junction, form air bridges.The n district that is exposed of p-n junction is received on one side of described air bridges, and another side is received the p district of adjacent p-n junction.
[7] application of transmitting by the limited beam that has the circular section for luminous power, send by optical fiber as luminous power, shown in Fig. 2 (this Fig. 2 is the reproduction of Virshup patent document Fig. 3), these a plurality of p-n junction elements generally are divided into a plurality of fan-shaped device piecemeals 28 by the circular photosensitive region with semiconductor chip and make, described piecemeal 28 is isolated from each other by etching bath 26, and is connected in series by interconnection bridge 40; Though shown 6 piecemeals among the figure, typical devices can have 2-16 or more a plurality of piecemeals.
Summary of the invention
[10] one of purpose of the present invention is to overcome at least shortcomings more of the prior art, and the luminous power transducer of improvement is provided, and the luminous power transducer of described improvement has lower leakage current, the lower internal resistance and the light conversion efficiency of improvement.
[11] another object of the present invention provides a kind of efficient luminous power transducer that is operated in 1.3 μ m to 1.55 mum wavelength scopes.
[12] according to the present invention, a kind of photovoltaic power converter is provided, it comprises, semiconductor base material is by first sandwich construction of described substrate support; Described first sandwich construction comprises first conductive layer of the semi-conducting material of first emitter layer of semi-conducting material of first base layer, second conduction type of the semi-conducting material of first conduction type and second conduction type; Described first base layer is positioned on the described substrate and has first forbidden band; Described first emitter layer is adjacent with described first base layer, described second conduction type and described first conductivity type opposite, thereby form first tie region between described first emitter layer and described first base layer, described first emitter layer has second forbidden band that is equal to or greater than described first forbidden band; Described first conductive layer is set on described first emitter layer, and described first conductive layer has any the 3rd forbidden band of being wider than in first and second forbidden bands.First current barrier layer of the semi-conducting material of second conduction type is between described substrate and described first sandwich construction.The base stage electrical contact is configured to be used for and the described first base layer electric connection, the emitter electrical contact is set on the described conductive layer, be used for and the described first emitter layer electric connection, thereby produce relative voltage for described base stage electrical contact in response to the radiation of inciding the selected wavelength on described first emitter layer.
[13] according to an aspect of the present invention, at least one in described first emitter layer and the described conductive layer be by carbon dope, thereby make the acceptor doping concentration range 2 * 10 18To 1 * 10 19Cm -3
[14] photovoltaic power converter of the present invention may further include a plurality of grooves, described groove extends through described first sandwich construction and current barrier layer, and further extend partially into substrate, thereby form the device piecemeal that separates on a plurality of spaces by described substrate support; Each described device piecemeal comprises first metal contact and second metal contact, described first metal contact is used for and the first interior base layer electric connection of device piecemeal, described first metal contact is set on first base layer in the opening of described first emitter layer, described second metal contact is set on the conductive layer of described device piecemeal, is used for and the described first emitter layer electric connection.Provide a plurality of electric interconnectors, be used for each and only one first metal contact be electrically connected to the second adjacent separately metal contact, thereby form the device piecemeal chain that is connected in series, wherein, one first metal contact that is not connected in arbitrary second metal contact in described first metal contact is the base stage electrical contact, and one second metal contact that is not connected in arbitrary first metal contact in described second metal contact is the emitter electrical contact.
[15] according to an aspect of the present invention, described substrate, the semi-conducting material of each in first base layer and the emitter layer is GaAs, and the semi-conducting material of described conductive layer is a kind of alloy among AlGaAs and the InGaP.
[16] according to an aspect of the present invention, the semi-conducting material of described substrate and current barrier layer is InP, the semi-conducting material of described first base stage and emitter layer is a kind of alloy among InGaAs and the InGaAsP, and the semi-conducting material of described conductive layer is a kind of alloy among InP and the InGaAsP.
[17] in one embodiment of the invention, the semi-conducting material of described substrate is that doped level is less than 10 15Cm -3Have a GaAs that intrinsic electricity is roughly led; Described current barrier layer comprises the p Doped GaAs, and the acceptor doping concentration range of described p Doped GaAs is at 5 x 10 17To 1 x 10 19Cm -3, thickness range is 0.1 to 0.3 μ m; Described resilient coating comprises n Doped GaAs p, and the donor doping concentration range of described n Doped GaAs is at 5 x 10 17To 2 x 10 18Cm -3, thickness range is 1 to 10 μ m; Described first base layer comprises that GaAs and aluminium doping content are no more than a kind of in 35% the AlGaAs alloy, and its donor doping range of concentrations is 5 x 10 17To 1 x 10 19Cm -3, thickness range is 1 to 3 μ m; Described first emitter layer comprises that GaAs and aluminium doping content are no more than a kind of carbon doped layer in 35% the AlGaAs alloy, and its thickness range is 0.6 to 1 μ m, and the acceptor doping concentration range is at 2 x 10 18To 5 x 10 18Cm -3And, described conductive layer is the p type, comprise following one of them: Zn or Be doping InGaAsP, be no more than 35% carbon doped with Al GaAs with the aluminium doping content, and the forbidden band of described first emitter and base layer is wider than in the forbidden band that has of described conductive layer, thickness range is 1 to 3 μ m, and the donor doping concentration range is 2 x 10 18To 2 x 10 19Cm -3
[18] in another specific embodiment of the present invention, the semi-conducting material of described substrate is a semi-insulating indium phosphate (InP); Described current barrier layer comprises that acceptor doping concentration is 5 x 10 17Cm -3Or higher p doping InP, thickness range is 0.2 to 0.3 μ m; Described resilient coating comprises that donor doping concentration is 5 x 10 17Cm -3Or higher n doping InP, thickness range is 5 to 10 μ m; Described first base layer comprises the InGaAs alloy with the InP lattice match, and its donor doping concentration is 5 x 10 17Cm -3Or higher, thickness range is 1 to 3 μ m; Described first emitter layer comprises and the p doping InGaAs alloy of InP lattice match that its acceptor doping concentration is 2 x 10 18Cm -3Or higher, thickness range is 0.5 to 1.5 μ m; And described conductive layer comprises that donor doping concentration is 2 x 10 18Cm -3Or higher p doping InP, its thickness range is 1.5 to 2.5 μ m.
Description of drawings
[19] below in conjunction with the accompanying drawing more detailed description the present invention who represents the preferred embodiment of the present invention, wherein, identical reference identification is used to indicate identical device, wherein:
[20] Fig. 1 is the layer structural representation of the optical semiconductor energy converter under the prior art;
[21] Fig. 2 is the plane graph of the sectional type optical semiconductor energy converter under the prior art;
[22] Fig. 3 is the plane graph of photovoltaic power converter according to an embodiment of the invention, and described photovoltaic power converter contains core;
[23] Fig. 4 is the sectional view along the A-A line of photovoltaic power converter shown in Figure 3, so that its illustrative layers structure to be described;
[24] Fig. 5 is the sectional view along B-B line among Fig. 3 of Fig. 3 and photovoltaic power converter shown in Figure 4;
[25] Fig. 6 is the plane graph of photovoltaic power converter according to an embodiment of the invention, and described photovoltaic power converter contains independent addressable core;
[26] Fig. 7 is the sectional view along C-C line among Fig. 6 and D-D line of an exemplary embodiment of photovoltaic power converter shown in Figure 6;
[27] Fig. 8 is the sectional view along C-C line among Fig. 6 and D-D line of another optional embodiment of photovoltaic power converter shown in Figure 6;
[28] Fig. 9 is current-voltage (I-V) characteristic of GaAs/AlGaAs photovoltaic power converter according to the present invention under the 50mW illumination condition and the curve synoptic diagram of power output-voltage (P-V) characteristic;
[29] Figure 10 be InGaAs/InP photovoltaic power converter according to the present invention at wavelength 1430nm, the curve synoptic diagram of (I-V) characteristic of the current-voltage under the illumination condition of intensity 100mW and power output-voltage (P-V) characteristic.
Embodiment
[30] below at first the example embodiment with reference to Fig. 3,4 and 5 pairs of photovoltaic power converters of the present invention (PPC) be described.
[31] at first referring to Fig. 3, PPC 50 contains multiple arrangement piecemeal 51-55, described piecemeal is arranged with circular compound mode, it has core or center piecemeal 55 and a plurality of described center piecemeal 55 piecemeal 51-54 on every side that is arranged on, and described a plurality of piecemeals form circulus around described center piecemeal 55.Piecemeal 51-54 and center piecemeal 55 are isolated from each other by narrow groove 100 and 200, and each piecemeal 51-54 is at this ring-type piecemeal that is otherwise known as.Annular or be generally unremitting groove 200 center piecemeal 55 is isolated with other ring-type piecemeals 51-54, and groove 100 radially extends and each ring-type piecemeal 51-54 is isolated from each other from groove 200.Groove 100 and 200 adopts in the etching technique field the known method with high aspect ratio to carry out etching in epitaxially grown semiconductor wafer, and described engraving method with high aspect ratio is reactive ion etch method (RIE) for example.Electric interconnector 70 is connected piecemeal 51-55 between contact mat 61 and 62, electric interconnector 70 will describe in further detail hereinafter with the form of air bridges, so that described device can produce voltage on each piecemeal during by the rayed of suitable wavelength, thereby the voltage that produces on each piecemeal is added up, to produce higher respectively output voltage V between contact mat 61 and 62 OutThough the PPC50 shown in Fig. 3 has only four ring-type piecemeals, the ring-type piecemeal that contains among other embodiment can be lower than the quantity that maybe can be higher than the piecemeal of ring-type shown in Fig. 3, so that higher output voltage is provided.Usually, the device based on low gap material will need more to install piecemeal to realize for example desired output voltage values V of 6V OutFor example, hereinafter the InP based devices of Miao Shuing may have 12 or multiple arrangement piecemeal more, and the GaAs based devices may be suitable for disposing 5 device piecemeals.
[32] Fig. 4 is the partial cross section figure of edge " A-A " line of PPC shown in Fig. 3 50, in order to the layer structure of explanation PPC 50; Described layer structure comprises a semi-insulating or dielectric base 130, first current barrier layer 131, and first sandwich construction 30, described first sandwich construction 30 comprises the resilient coating 132 of the first electric conductivity type of first semi-conducting material successively, first base layer 133 of the first electric conductivity type with first semi-conducting material of first energy gap, first emitter layer 134 of the second electric conductivity type (betwixt to form p-n junction zone 129) opposite with second semi-conducting material of second energy gap, and the conductive layer 136 of the second electric conductivity type of the 3rd semi-conducting material with the described first electric conductivity type.Described first and second semi-conducting materials are used to absorb incident light and produce minority photoinduction charge carrier at emitter layer and base layer, electric field by p-n junction zone 129 sucks contiguous emitter layer or base layer with described photoinduction charge carrier then, minority carrier becomes majority carrier and is described first emitter layer 134 and base layer 133 chargings in the emitter layer of described vicinity or base layer, described first emitter layer 134 and base layer 133 will be called as first active layer hereinafter, thereby its electric charge with opposite polarity produces photoinduction voltage.The 3rd semi-conducting material of conductive layer 136 is transparent to incident light and contains the 3rd forbidden band that the forbidden band of any material in first semi-conducting material that forms first base layer 133 and second semi-conducting material that forms first emitter layer 134 is wider than in described the 3rd forbidden band.Alternatively, can be deposited on conductive layer 136 tops, form ohmic contact preferably with first metal contact 60 and gridline (not illustrating in the drawings) so that help to the contact layer or the protective layer 101 of the second transparent conduction type of incident light.Described term " forbidden band (bandgap) " and " energy gap (energy bandgap) " are used interchangeably in this application, refer to the capacity volume variance between the bottom of valence band top and conduction band in the semi-conducting material.
[33] resilient coating 132 that is positioned at base layer 133 belows is thicker than base layer 133 and emitter layer 134 relatively.In operation, resilient coating 132 work that plays second conductive layer moves to separately first metal contact 65 in order to the photo-generated carrier that helps described first utmost point; Resilient coating 132 has low sheet resistance, preferably less than 1 ohm/cm 2The substrate 130 and first current barrier layer 131 can adopt first semi-conducting material, promptly the material with the resilient coating 132 and first base layer 133 is identical, with the epitaxial growth of the high-quality base layer 133 that helps to have fabricating low-defect-density, described defective will cause the non-radiative compound of photoinduction charge carrier.Described second semi-conducting material, the material of promptly described first emitter layer preferably adopt identical with described first semi-conducting material or are higher than its forbidden band and in fact have identical lattice constant with described first semi-conducting material.
[34] substrate 130 should have high resistivity so that stop the photo-generated carrier that flows in the resilient coating 132 to pass substrate 130 and seepage, and the seepage of described charge carrier will reduce the output voltage of PPC 50 and therefore reduce the performance of PPC 50.Because doping and to have the high-quality substrate that the optimal semi-conducting material of intrinsic conductivity makes only be half insulation not, so, substrate 130 can be the intrinsic insulation or the semi-insulating substrate of being made by described first semi-conducting material, and described first conductor material preferably has and is not less than 10 7The resistivity of ohm/cm.For the selection of substrate, preferably not doping GaAs or InP substrate, the background doping of described GaAs or InP substrate is no more than 10 15Cm -3Such background doping will guarantee not have in the substrate direct current conduction, not wish the photoinduction conduction of current that occurs in the substrate but can not stop.
[35] favourable part is, according to the present invention, first current barrier layer 131 is inserted between semi-insulating layer substrate 130 and the resilient coating 132, first current barrier layer 131 has the second electric conductivity type opposite with the first electric conductivity type of resilient coating 132, and therefore form a p-n junction 127 with resilient coating 132, described p-n junction 127 stops the majority carrier of resilient coatings 132 to flow into substrate 130, so that further suppress between the piecemeal of described device the seepage electric current by substrate 130.P-n junction 127 between current barrier layer 131 and resilient coating 132 is called as the current countercheck 127 or first current countercheck hereinafter.
[36] although the first electric conductivity type can be that p type electricity is led in according to other embodiments of the invention, and being n type electricity, the second electric conductivity type leads, the first electric conductivity type among the embodiment described herein is that n type electricity is led, and leads and the second electric conductivity type is a p type electricity.Described n type be meant be mixed with dopant material or provide donor impurity the electricity of semi-conducting material lead, the most of charge carriers in the described semi-conducting material are electronics; Described p type is meant that the electricity of the semi-conducting material that is mixed with dopant material or acceptor impurity is provided leads, and the most of charge carriers in the described semi-conducting material are the hole.When term " n (p)-type " and " n (p)-doping " when referring to the electric conductivity type separately of semi-conducting material, can exchange use at this.Hereinafter employed " doping level " refers to the net concentration of donor impurity in the n N-type semiconductor N material, or refers to the net concentration of acceptor impurity in the p N-type semiconductor N material.
[37] described first base layer can be mixed with concentration range 5 * 10 17Cm -3To 1 * 10 19Cm -3Donor impurity.Described first base layer can be mixed with concentration and be higher than 5 * 10 17Cm -3Acceptor impurity, or preferably be mixed with concentration range 2 * 10 18To 1 * 10 19Cm -3Acceptor impurity, or most preferably be and be mixed with concentration range 3 * 10 18To 5 * 10 18Cm -3Acceptor impurity.In other embodiments, the donor impurity concentration that described first base layer can be mixed with is from increasing gradually to current barrier layer 131 away from p-n junction zone 129, and its concentration range is from less than 2 * 10 17Cm -3To being at least 2 * 10 18Cm -3Similarly, the acceptor impurity of described emitter layer is from increasing gradually to conductive layer 136 away from p-n junction zone 129, and its concentration level is from less than 2 * 10 17Cm -3To being at least 2 * 10 18Cm -3
[38] in first preferred embodiment; the semi-conducting material of substrate 130, current barrier layer 131, resilient coating 132, first base layer 133 and first emitter layer 134 adopts GaAs (GaAs); the semi-conducting material of conductive layer 136 and optional window layer 135 adopts a kind of among InGaP and the AlGaAs or both, and the semi-conducting material of described optional protective layer adopts GaAs (GaAs).
[39] more specifically, substrate 30 is formed by plain GaAs in fact, and the background doping level of substrate 30 is no more than 10 15Cm -3And the thickness that can have the hundreds of micron, for example thickness range is between 350 microns to 650 microns.Current barrier layer 131 epitaxial growth in substrate 30, and the semi-conducting material of current barrier layer 131 is p-type GaAs, and the acceptor impurity concentration range of described p-type GaAs is 5 * 10 17Cm -3To 1 * 10 19Cm -3Between, perhaps for example concentration approximately is 2 * 10 18Cm -3, and thickness range between 0.2 to 0.3 micron for example 0.25 micron.Resilient coating 132 is epitaxially grown on the current barrier layer 131, and the semi-conducting material of described resilient coating 132 is the highly doped GaAs of n type, and the donor concentration scope of the highly doped GaAs of described n type is 5 * 10 17Cm -3To 2 * 10 18Cm -3Between, and thickness range is between 1 to 10 micron, and for example 5 microns.First base layer 133 is epitaxially grown on the resilient coating 132, and the semi-conducting material of described first base layer 133 also is n type GaAs, and the donor concentration scope of described n type GaAs is 5 * 10 17Cm -3To 2 * 10 18Cm -3Between for example 1 * 10 18Cm -3, and thickness range is approximately 3 microns.First emitter layer 134 is epitaxially grown on first base layer 133, and the semi-conducting material of described first emitter layer 134 is p type GaAs, and the acceptor impurity concentration range of described p type GaAs is 2 * 10 18Cm -3To 1 * 10 19Cm -3Between, preferably 3 * 10 18Cm -3To 5 * 10 18Cm -3Between, and thickness range is between 0.2 to 1 micron, and for example 0.8 micron.Described p-n junction zone 129 is formed between first base layer 133 and first emitter layer 134.
[40] optional window layer 135 is epitaxially grown on first emitter layer 134, and the semi-conducting material of described optional window layer 135 is first alloys of GaAs, for example AlGaAs or more particularly Al xGa 1-xAs, described Al xGa 1-xThe relative amount x of As Aluminum in Alloy〉50%, x=80% for example.Optional window layer 135 has with first emitter layer, 134 identical or higher p type electricity leads.Why select for use AlGaAs to be because its light permeable rate for the selected radiation wavelength of PPC 50 work, and because the passivation of first emitter layer 134, thereby reduce the non-radiative recombination rate of the photoinduction charge carrier on the interface of first emitter layer 134 and layer thereafter.The acceptor impurity concentration of optional window layer 135 can be 5 * 10 18Cm -3And its thickness range can be between 0.02 to 0.1 micron, for example 0.08 micron.
[41] the p utmost point layer that conductive layer 136 can high-dopant concentration, the acceptor impurity concentration range of the p utmost point layer of described high-dopant concentration is 2 * 10 18Cm -3To 2 * 10 19Cm -3Between, and be preferably 3 * 10 18Cm -3Perhaps higher, to reduce the surface impedance of conductive layer 136.The semi-conducting material of conductive layer 136 can be second alloy of AlGaAs, for example Al xGa 1-xAs, described Al xGa 1-xThe relative amount of aluminium is less than 50% among the As,, for example 20%, and its thickness range is between 1 to 3 micron, and for example 2 microns.Aluminium content x in second alloy of the AlGaAs of conductive layer 136 should be enough high, to guarantee the light permeable rate of conductive layer 136 for the incident radiation of selected wavelength.On the other hand, the described aluminium content that reduces described conductive layer helps reducing its surface impedance because reduced described conductive layer do not wish the oxidation that occurs.
[42] therefore,, utilize the conductive layer 136 do not contain aluminium according to an optional embodiment of the present invention, the p-doped layer of InGaP alloy for example, described InGaP alloy for example is In xGa 1-xThe synthetic material of P, wherein the scope of x is between 0.5 to 0.54.Described layer can surpass epitaxial growth on the optional window layer 135 of 50% AlGaAs first alloy at aluminium content, or directly epitaxial growth on first emitter layer 134 of p-Doped GaAs.
[43] another aspect of the present invention relates to carbon (C) as preferred dopant material, described carbon (C) dopant material is used for the p-doped layer of the PPC 50 of the preferred embodiments of the present invention, described p-doped layer such as current barrier layer 131, first emitter layer 134, optional window layer 135 and conductive layer 136, described carbon (C) dopant material is in order to replace comparatively traditional p-dopant material such as beryllium (Be) and zinc (Zn), and described beryllium (Be) and zinc (Zn) generally are used for GaAs base and InP base optoelectronic device.Advantageously, the use of described carbon (C) dopant material can be strengthened p-and mixes in first emitter layer 134 and cross over the electric field strength in p-n junction zone 129 and the internal quantum that increases described PPC.Conventional dopant is as zinc, greater than 5 * 10 17Cm -3The highly doped level effect that the time may occur being harmful to, reduce as the life-span of minority carrier, however described carbon (C) mix and will can not produce described ill-effect, perhaps reduce greatly to major general's ill-effect.Described carbon (C) mixes and makes the semi-conducting material of high doped GaAs or InGaAs can keep the life-span of minority carrier well and therefore help active layer 133/134 to realize high-quantum efficiency, and promptly described p-n junction zone 129 is being left under the radiation recombination situation nothing but in light induced electron and hole at high proportion.Therefore, as dopant material, the p-doping level of first emitter layer 134 can be issued to 5 * 10 in the quantum efficiency condition that does not reduce described device substantially with carbon 18Cm -3In contrast, adopt as traditional dopant material of zinc at highly doped grade, as greater than 2 * 10 18Cm -3The time, the p utmost point layer in p-n junction zone 129 will produce extra non-radiative recombination center and reduce minority carrier lifetime, thus the photoelectric current and/or the output voltage that cause the reduction of quantum efficiency and cause described PPC to produce diminish.In addition, more traditional acceptor impurity of carbon ion spatial distribution in the semiconductor host material such as Zn and Be have more stability.By this stability, carbon mixes and can partly and between the n utmost point part form steeper high gradient interface at the p utmost point in described p-n junction zone 129, help to make p-n junction to obtain stronger electric field and make from the move to the interior mobility of the photoproduction minority carrier that shifts out of p-n junction highlyer, help producing photogenerated current.The described carbon of conductive layer 136 mixes can be by providing higher quality material with highly doped level reducing the surface impedance of conductive layer 136, and the InGaP material that contains less aluminium in especially described higher quality material and the described conductive layer 136 more helps reducing described surface impedance when being used in combination.
[44] the foregoing description is directly light to be transformed into electrical power, described optical wavelength range is between 0.8 to 0.9 micron, the forbidden band of GaAs by described conductive layer and the forbidden band of AlGaAs/InGaP describe in detail, and the semi-conducting material of wherein said base layer 133 and described emitter layer 134 is GaAs.No matter those skilled in the art can judge short wavelength light or longwave optical can be converted by described PPC50, described PPC50 is by using the AlGaAs that is complementary with described GaAs substrate or InGaAs alloy-layer grid as described buffer 132 and described emitter layer 134, and suitably adjusts the metal deposition of described conductive layer 136.For example, the Al of aluminium content x from 5% to 35% xGa (1-x)The As alloy can be used to described first active layer 133 and 134, and the higher Al of other aluminium content xGa (1-x)As alloy or InGaP alloy can be used to described conductive layer 136, and described alloy phase has higher forbidden band for the semi-conducting material of described first active layer 133 and 134.By using AlGaAs or InGaAs growth to make described first active layer 133/134 in the GaAs substrate, the described PPC 50 manufactured optical wavelength range that are applicable to are approximately from 0.7 micron to about 1.3 microns.The forbidden band of described conductive layer 136 can be higher than the forbidden band of described emitter layer 134 between 0.15eV and 0.5eV (electron-volt), be used for by the light permeable rate of 133/134 layer of incident light that is absorbed of described first active layer so that guarantee described conductive layer 136.
[45] other embodiment of described PPC 50 use a layer structure, the epitaxial growth in indium phosphate (InP) substrate of described layer structure, and described PPC 50 is applicable to the light of Wavelength-converting scope between 1.2 microns to 1.6 microns, and most of commercial fibres all have low light loss in described wave-length coverage.For example, an example among described other embodiment, described PPC50 can use following semi-conducting material in its layer structure.The semi-conducting material of described substrate 130 is semi-insulator InP, and it is 10 that described semi-insulator InP is mixed with content 16Cm -3Iron (Fe) impurity and have 10 7The high resistivity of ohm/cm.Described current blockade layer 131 is the p type InP layers that are mixed with impurity, the thickness range of described p utmost point layer between 0.2 micron to 0.3 micron, for example 0.25 micron, and doping level is 5 * 10 17Cm -3Or it is higher; Described resilient coating 132 is the n utmost point layers that are mixed with InP impurity, the thickness range of described n utmost point layer between 5 microns to 10 microns, for example 7 microns, and doping level is 5 * 10 17Cm -3Or it is higher; The semi-conducting material of described first base layer 133 is n utmost point InGaAs alloy-layers, and described InGaAs alloy-layer and InP layer crystal lattice coupling and its thickness range be at 1 micron to 3 microns, for example 3 microns, and donor impurity concentration is 5 * 10 17Cm -3Or it is higher; Described first emitter layer 134 is p utmost point InGaAs alloy-layers, and described InGaAs alloy-layer and InP layer crystal lattice coupling and its thickness range be at 0.5 micron to 1.5 microns, for example 1 micron, and the acceptor impurity concentration range is 2 * 10 18Cm -3To 1 * 10 19Cm -3Between or preferable range 3 * 10 18Cm -3To 5 * 10 18Cm -3Between and with carbon impurity as preferred dopant material; Described conductive layer 136 is the p utmost point layers that are mixed with InP impurity, the thickness range of described p utmost point layer between 1.5 microns to 2.5 microns, for example 2 microns, and the acceptor impurity concentration range is 2 * 10 18Cm -3To 2 * 10 19Cm -3Between, and preferred concentration range for surpasses 3 * 10 18Cm -3For example, p utmost point InP layer 131 and 136 dopant material can be Be.The semi-conducting material of described contact layer 101 is p utmost point InGaAs alloy-layers, and preferred carbon impurity is as dopant material, and doping level is approximately 2 * 10 18Cm -3Or higher, and the thickness range of described p utmost point layer is between 0.1 micron to 0.2 micron.
[46] referring to Fig. 3, the described device piecemeal 51-55 of described PPC50 makes by the described groove 100 and 200 that forms by the PPC wafer of aforementioned layers structure, described groove 100 and 200 extends beyond described first sandwich construction 30 and described current blockade layer 131, and extend partially into described substrate 130, so that between the described device piecemeal 51-55 electric isolation and spatial separation and described device piecemeal 51-55 by described substrate support, described substrate is semi-insulator at least, and the resistance coefficient that promptly contains is no more than 10 7Ohm/cm, so as with described current blockade layer 131 acting in conjunction to reduce the seepage electric current that described device divides interblock.
[47] degree of depth of described groove is determined according to the gross thickness of described first sandwich construction 30, and scope can be between 10 microns to 20 microns.Described groove 100 and 200 aspect ratio should suitably improve so that the segmentation of incident optical minimizes, the segmentation of described incident optical arrives described base material, described base material is positioned at the bottom of described groove, described aspect ratio is determined by the ditch groove depth 575 and the ratio of ditch groove width 573, described ditch groove depth and ditch groove width use " arrow " to mark in Fig. 4 respectively, because described light will be absorbed and produce photocarrier at described base material place and therefore cause the unnecessary increase of described base material specific conductance, thereby divide interblock to cause potential electric guiding path at described device, described electric guiding path will cause the reduction of described PPC device light transfer ratio.Therefore, described groove 100 and 200 should be suitably narrow, and preferred described groove wide region is between 2 microns to 10 microns, and for example 5 microns or littler, and the aspect ratio of described groove 100 and 200 should and be preferably greater than 5 greater than 4.Described current blockade layer 131 stops the majority carrier in the described resilient coating 132 to flow to described substrate from it, therefore described current blockade layer 131 will stop seepage electric current that described device divides interblock by described substrate 130, with the surprising raising of light transfer ratio acquisition with respect to the similar installation that does not contain described current blockade layer 131 of light transfer ratio that described PPC 50 is installed.Described term " light transfer ratio and power conversion rate " can be used alternatingly at this, and the both is defined as the ratio of luminous power that is offered the incident light of the electrical power of external circuit and described PPC device by described PPC device.
[48] in each piece piecemeal of described device piecemeal 51-55; first metal contact 65 is deposited on the electric connection that is used on described first base layer 133 with described first base layer, and second metal contact 60 is deposited on the described optional protective layer 101 or directly be deposited on the electric connection that is used on the described conductive layer 136 with described first emission layer 134 when not having described optional protective layer.Electric interconnector 70 is connected each described first metal contact 65 with the form of metal-air bridge but each air bridges only connects described second metal contact of described first metal contact and a vicinity with described second metal contact of nearby device piecemeal then, so that all described device piecemeal 51-55 realize series connection.When projecting on the described PPC 50, add voltage in order to produce higher total output voltage V in described first metal contact and the described second metal contact place through the light of selecting OutDescribed light through selection is selected by the absorption region of described first active layer 133/134 and the transmission range of described conductive layer 136, described voltage results from the p-n junction zone 129 of each piece piecemeal of described device piecemeal 51-55, and described first metal contact does not keep being connected with any other first and second metal contact with described second metal contact.These not with any other first and second metal contact keep described first metal contact be connected and described second metal contact at this respectively as the electrical contact of base stage and emitter; Described contact can be connected to contact mat 61 and 62 so that be connected to the external circuit of described PPC 50 by air bridges 71.
[49] embodiment as shown in Figure 3, described second metal contact 60 of described device piecemeal 51 can be connected to described first metal contact 65 of described device piecemeal 52 by air bridges 70, and cross section, described contact is as shown in Figure 4.Described second metal contact 60 of described device piecemeal 51 can be connected to described first metal contact 65 of described device center piecemeal 55 by air bridges 70, and described second metal contact 60 of described device center piecemeal 55 is connected to described first metal contact 65 of described device piecemeal 53 by air bridges.Described first metal contact 65 of described device center piecemeal 55 and described second metal contact 60 all have circulus and relate to hereinafter described first and second contacts.Described center contact 60 and 65 is provided with around described center piecemeal 55, the described first ring-type contact, the 65 contiguous annular ditch grooves 200 and the described second ring-type contact 60 of described center piecemeal 55 are positioned at described center piecemeal 55 and are close to the described first ring-type contact 65, the described as shown in Figure 5 first ring-type contact 65 is positioned at opening 73, Fig. 5 is the sectional view that is used to illustrate the layer structure of photovoltaic power converter, and described layer structure is the sectional view along the B-B of line shown in Fig. 3.There is an opening 61 at the described first ring-type contact 65 places, air bridges 70 is connected to described first metal contact 65 places of nearby device piecemeal by described opening 61 with the described second ring-type contact 60, and described second metal contact is connected to described first metal contact of described last device piecemeal 54 by another air bridges 70.This mutual syndeton causes each described device piecemeal 51,52,53,54 and 55 to be connected sequentially, and described series system obtains the output voltage V between described emitter electrical contact and base layer electrical contact Out, promptly between described second metal contact 60 of described second metal contact of described device piecemeal 54 and described device piecemeal 51, producing output voltage, described output voltage approaches the total value that each piecemeal p-n junction place of described device piecemeal 51-55 produces voltage.Described device piecemeal 54 keeps being connected with 62 metal with described metal contact pad 61 (as shown in Figure 3) by air bridges 71 with 51, and described metal contact pad 61 and 62 is respectively as anode and the negative electrode of described PPC 50.
[50] described first and second Metal Contact electricity 65 and 60 can deposit in single metal coating operation, carries out structure of contact terminal production process and air bridges 70 and 71 after described coat of metal operation is finished and makes, described in the Virshup patent.The outside of described device piecemeal 51-54 is more suitable for carrying out the described second ring-type contact, 60 depositions; so that with the metal gate ruling overlaid on the described protective layer 101, and described center piecemeal 55 directly precipitates on described contact protection layer 101 without any metal gate ruling and the corresponding described second annular contact 60 of each piecemeal.Described first and second annular contacts 65 of described center piecemeal 55 and 60 width should be suitable narrow is so that leave most of zone on described contact protection layer 101 surface of described center piecemeal 55 for incident light.Via embodiment as can be known, the peripheral circumferential diameter of described annular piecemeal 51-54 is 1800 microns, and the circle diameter of described center piecemeal is 250 microns, and the width range of described ring- type contact 65 and 60 is between 10 microns to 50 microns.
[51] deposit described first metal contact 64 earlier, being arranged in described first base layer 133 of respectively installing piecemeal comes out at the select location of each device piecemeal, preferably near groove, described groove can be with described first base layer 133 and apparatus adjacent zone isolation, by selecting etching method, be etched to the top of described first base layer 133 so that forming opening 73 from the top of described sandwich construction 30, and in described first emitter layer 134 deposition described first metal contact 65, as shown in Figure 4, Fig. 4 is the sectional view that is used for the layer structure of photovoltaic power converter shown in the key diagram 3, and described layer structure is the sectional view along the A-A of line shown in Fig. 3.
[52] the device partitioning placement of PPC50 described in the present invention has novel technical characterictic, compare with " fan-shaped wedge " under the prior art among Fig. 1 and to help the luminous power conversion efficiency that provides higher, in device partitioning placement of the present invention the device piecemeal 55 be positioned at the center and by one group of device piecemeal 51-54 around, described device piecemeal 51-54 is precipitation around center piecemeal 55, and groove 26 described in the prior art of Fig. 1 all converges at the center of described PPC with hollow one of the effective formation in the center of described device photosensitive surface.Described prior art seriously influences the conversion efficiency of the light energy transducer under the prior art condition, wherein incident light enters with the form of light beam, the density of described light beam is outwards successively decreased from beam axis, the Gauss who for example sends from monomode fiber or be similar to Gauss's light beam.Part is, the defective that PPC 50 of the present invention eliminates in the prior-art devices is positioned at the piecemeal 55 at device center by utilization, and described piecemeal 55 can utilize the light at incident beam center, the light intensity maximum at described incident center.According to the incident light density distribution described PPC is carried out geometric manipulations, the negative influence that uneven fortune irradiation layout produces is avoided greatly.We find that by adopting the center fixture piecemeal 55 of appropriate size, the light conversion efficiency of described PPC 50 has improved 25%, contains 5 piecemeals among the described PPC 50.We find again, for the luminous power with Gaussian beam is converted to electrical power effectively, the ratio of the area of the photosensitive surface that described center piecemeal 55 is had and the gross area of the photosensitive surface that described PPC 50 is had preferably between 15% and 25%, more preferably 20%.Yet, being actually identical at incident intensity described in the application at the photosensitive surface of described PPC 50, the area of the photosensitive surface of described piecemeal 51-54 equates.Notice that term " photosensitive surface " is used to define the surface that incident light arrives the described PPC that described active layer passes, described active layer is used to absorb incident light and converts thereof into electric current.The photosensitive surface of PPC 50 is the part that all device piecemeal 51-55 accept the gross area of light, and as shown in Figure 3, described photosensitive surface is not covered by metal.Term " photosensitive surface " is used herein to the photosensitive surface of each piecemeal of definition.Another favourable part is, described center piecemeal 55 makes in the device nonessential voltage drop reduce and be connected to described contact mat 61 and 62 with impedance path that described impedance path is the path that charge carrier produces and conducts in device.By the light that the center piecemeal is caught, electric current does not need the long Distance Transmission by impedance material, but can directly be collected at piecemeal place, contiguous center and transmit by the metal gate ruling, and described metal gate ruling has low impedance with respect to the girth of device.In the prior art, the method that does not have use device core collected current.
[53] referring to Fig. 6, the PPC 150 that provides according to another embodiment of the invention, wherein said center piecemeal 55 are independent of that annular piecemeal 51-54 connects and are isolated with its electricity.PPC described in the present embodiment 150 has 4 ports, comprises the center fixture piecemeal 55 as the first device part, and described piecemeal is with electricity is isolated mutually as the second device annular piecemeal 51-54 partly, and described first device partly can independently be electrically connected.Described annular piecemeal 51-54 partly is called for short annular section connecing contact mat 261 and 262 series connection with the ring device that forms among the described PPC 150.Note among Fig. 3-7, identical numeral is used to represent that components identical is with simplified illustration and help to understand embodiment, just, the first and second annular contacts of center piecemeal 55 are denoted as 109 and 108 in the present embodiment respectively, so that it is distinguished mutually with first and second metal contact 65 and 60 of annular piecemeal 51-55, described first and second metal contact 65 and 60 as shown in Figure 4.Different with first and second metal contact that are connected to annular piecemeal separately among the PPC 50, the described first and second annular contacts 109 and 108 of the described center fixture piecemeal 55 of described PPC 150 are connected to respectively by electric guiding path 118 and 119 and connect contact mat 263 and 264, described electric guiding path 118 and 119 width are preferably less than 15 microns, described electric guiding path 118 and 119 is positioned at adjacent trenches 100 places, and described groove 100 is separated two annular piecemeals of described device.Described electric guiding path 118 and 119 is set on described device piecemeal 51 and 54 and described device piecemeal extends to excircle from the inner periphery of described electric guiding path; but second current barrier layer 106 makes the insulation of described electric guiding path and described device piecemeal, and the electrical conductance that described second current barrier layer epitaxial growth and described second current barrier layer on described protective layer 101 have is opposite with the electrical conductance of described protective layer 101.Described electric guiding path 118 and 119 also is called as third and fourth metal contact respectively at this.Described third and fourth metal contact is crossed over described ring device part and is stretched out, and with the device piecemeal electric insulation of described ring device part be connected to external circuit so that be independent of the device piecemeal 51-54 of described ring device part.
[54] described second current barrier layer as shown in Figure 7, described Fig. 7 is PPC 150 along line " C-C " (dotted line 128 left sides) with along the cross sectional view of line " D-D " (dotted line 128 right sides) part.In the aforementioned embodiment; the semi-conducting material of the substrate 130 and first active layer 133/134 is GaAs; the semi-conducting material of conductive layer 136 and protective layer 101 is p types, and second current barrier layer 106 can be the n-Doped GaAs, and the doping level of described n-Doped GaAs is at least 5 * 10 17Cm -3And its thickness is 1 to 5 micron of scope. Electricity guiding path 119 and 118 can form in same coat of metal operation or in different metal coating operation with first and second metal contact 65 and 60, after finishing, coat of metal operation and then carries out the structure of contact terminal production process, second barrier layer 106 is removed after electric guiding path 119 and 118 forms, and only keeps the part that is located immediately at described narrow metallic conductance path 119 and 118 belows.
[55] the device piecemeal 51-54 that connects between contact mat 261 and 262 connects by air bridges 70, outside the removal apparatus piecemeal 51, first metal contact 65 of every block assembly piecemeal 51-54 is connected to second metal contact 60 of next adjacent endless means piecemeal, so that device piecemeal 51-54 forms the chain that is linked in sequence, first metal contact 65 of first in described connection chain device piecemeal 51 is connected to by first air bridges 71 and connects contact mat 261, and second metal contact 60 of device piecemeal 54 is connected to by second air bridges 71 and connects contact mat 262.Connect contact mat 263 and 264 as the first of PPC 150 or the anode and the negative electrode of core 55, and connecing contact mat 261 and 262 as the second portion of PPC 150 or anode and the negative electrode of annular section 51-54, described annular section comprises the ring device piecemeal 51-54 that is linked in sequence.
[56] favourable part is, PPC 150 can be used as and combines the PPC and the integrating device of conventional photodetector (PD), the PPC part of described integrating device is corresponding to described annular section 51-54, and the PD of described integrating device part is corresponding to described core 55.When employing contains the rayed of suitable wavelength, described light wave contains the modulation composition that is loaded with data, described PPC 150 can provide electrical power and provide detection data in terminal 263 and 264, described electrical power is 5 volts or the higher signal form of voltage between device terminal 261 and 262, is used for for example driving external circuit.In addition, the core 55 of described device can adopt the forward bias from device positive pole terminal 263 and cathode terminal 264, to drive its active layer 133/134 to launch light but not absorbing light, therefore the core 55 of PPC 150 can be used as light-emitting diode (LED) use, for example is used for emission but not detection light data-signal.
[57] therefore, the invention provides one four port PPC, it has two independent addressable parts, be different from the luminous power transducer and PPC of the present invention 50 embodiment of prior art among Fig. 1, the luminous power transducer of prior art and PPC of the present invention 50 embodiment are the two-port devices among Fig. 1.Favourable part is that the independent addressing part of PPC 150 can be used to finish two different functions, for example carries out transform light energy and acceptance simultaneously or emission light data in same device.
[58] embodiment as shown in Figure 7, the core of PPC 150 adopts different area of space to survey or emission light in same p-n junction 129 respectively with annular section, and luminous energy is transformed into electric energy.Yet perhaps described p-n junction 129 is not to be suitable for most accepting or emission light data-signal, promptly is used to carry out described LED or PD function.And in some applications, light data-signal and luminous energy can carry by the light of different wave length.
[59] referring to Fig. 8, another embodiment of PPC 150 contains second sandwich construction 32, for example described structure is the p-i-n type, is set on first sandwich construction 30 in the center piecemeal 55, and described second sandwich construction 32 can be optimized to use as PD or LED.Described second sandwich construction 30 can contain second base layer 102 of the first electric conductivity type; described second base layer 102 epitaxial growth on protective layer 101; undoped layer or intrinsic layer 103 epitaxial growth on described second base layer 102 subsequently, and second emission layer 104 epitaxial growth on described intrinsic layer 103 of the second electric conductivity type.Then, second current barrier layer 106 epitaxial growth above second emission layer 104.After forming electric guiding path 118 and 119 by the coat of metal and structure fabrication operation, second current barrier layer 106 is removed, only keep being located immediately at the part of described electric guiding path 118 and 119 belows, so that provide and the electric insulation that is positioned at the semiconductor structure under it.
[60] second sandwich constructions 32 are retained in the center piecemeal 55, but can be removed in annular piecemeal 51-54, only keep the part that is positioned at electric guiding path 118 and 119 belows.As shown in the right side of dotted line among Fig. 8 128, the first annular contact 109 of center piecemeal 55 be set on the part that second base layer 102 exposes by breach with second base layer, 102 electric connections, described breach is in the intrinsic layer 103 and second emission layer 104.The second annular contact 108 of center piecemeal 55 be set on second emitter layer 104 with second emission layer, 104 electric connections.In the embodiment shown, second emitter layer 104 is that the p type and second base layer 102 are n types, the first annular contact 109 and the second annular contact 108 can form respectively by existing known n type and p type coat of metal technology, for example adopt the coat of metal technology of Au/Ge/Au to be used to form n type metal contact 108,118,119 and 65 and adopt the coat of metal technology of Ti/Pt/Au to be used to form p type metal contact 109 and 60.Metal-air bridge 107 is connected to electric guiding path 119 by the second annular contact 108 with second emission layer 104, successively electric guiding path 119 is connected to the anode tap 263 of p-i-n structure of the core 55 of PPC150 then by air bridges 111.Similarly, metal-air bridge 110 is connected to electric guiding path 118 by the first annular contact 109 with second base layer 102, successively electric guiding path 118 is connected to the cathode terminal 264 of p-i-n structure of the core 55 of PPC 150 then by air bridges 112.Etched trench 100 makes other parts of anode tap 263 and cathode terminal 264 and device isolated, air bridges 111 and 112 described etched trench 100 of mistake.
[61] for example, in containing the GaAs based devices of aforesaid first sandwich construction, the semi-conducting material of second base layer 102 can be the GaAs that n-mixes, and the donor impurity concentration range that described GaAs contains is about 5 * 10 17Cm -3To 2 * 10 18Cm -3And thickness range is between 1 to 5 micron, for example 3 microns; The semi-conducting material of intrinsic layer 103 can be unadulterated GaAs, and the background doping level that described GaAs contains is preferred little by 10 16Cm -3And thickness range is between 0.5 micron to 1.5 microns, for example 0.8 micron; And the semi-conducting material of second emission layer 104 can be the GaAs that p-mixes, and the acceptor impurity concentration range that described GaAs contains is near 5 * 10 17Cm -3To 2 * 10 18Cm -3And thickness range is between 0.5 micron to 1 micron, for example 0.8 micron.Second current barrier layer 106 also can be the GaAs that n-mixes, and the donor impurity concentration range of described GaAs is about 5 * 10 17Cm -3To 2 * 10 18Cm -3And thickness range is between 0.5 micron to 2 microns, for example 1.0 microns.In the GaAs of other PPC 150 base embodiment, second sandwich construction 32 can adopt AlGaAs or the making of InGaAs alloy material and its energy gap wide or narrow than first active layer 133 and 134, so that absorbing light also is converted into photocarrier, the light that active layer absorbed of described photocarrier and annular piecemeal 51-54 has a different set of optical wavelength.Described embodiment is favourable for the application that the light by different wave length transmits light energy and data.
[62] in a further exemplary embodiment, the semi-conducting material of substrate 130 is semi-insulator InP, each layer structure 131-136 in the described substrate 130 and 101 semi-conducting material please refer to about the embodiment of PPC 50 InP bases and discuss, and first active layer 133 and 134 InGaAs alloy-layer lattice and InP layer are complementary and the pairing wavelength of energy gap that has is approximately 1.48 microns.In PPC 150 embodiment, the semi-conducting material of second base layer 102 can be a n-doping InGaAsP alloy, and the pairing wavelength of the energy gap that the alloy compositions among the described InGaAsP for example has is approximately 1.3 microns, donor impurity concentration about 1 * 10 18Cm -3And the layer thickness scope is at 1 to 3 micron, for example 2 microns.The semi-conducting material of intrinsic layer 103 can be unadulterated InGaAsP alloy, has the thickness range of same alloy compositions and layer at 0.5 micron to 1.5 microns with second base layer 102, for example about 1 micron, and the semi-conducting material of second emission layer 104 can be p-doping InGaAsP, has same alloy compositions and its acceptor impurity concentration 5 * 10 with second base layer 102 17Cm -3To 5 * 10 18Cm -3Between or about 2 * 10 18Cm -3And the layer thickness scope is 0.5 micron to 1.5 microns or about 1 micron.Second current barrier layer 106 can be n-doping InGaAs, and its donor impurity concentration is greatly about 5 * 10 18Cm -3To 2 * 10 19Cm -3Between and layer thickness be 0.2 micron.It is 1.3 microns light data-signal that the embodiment of PPC 150 is suitable for surveying wavelength, and is suitable for operative wavelength is become electric flux in the high power laser signal transition of 1480nm, and described laser is from the diode laser generator that can produce wavelength 1480nm.The dopant material of InP layer and InGaAs layer can be Zn or Be.
[63] those skilled in the art can know, as the ternary material of InGaAs and InGaP and can epitaxial growth in the InP substrate as the various combination of the quaternary material of InGaAsP different-alloy, forming first and second sandwich constructions 30 and 32, thereby obtain the wavelength opereating specification greatly about the different embodiment of 1.2 microns to 1.6 microns PPC 150.Can be used for the epitaxial growth of ternary material layer and quaternary material layer as the conventional growth technology of molecular beam epitaxy (MBE) and mocvd method (MOCVD), the layer structure of the laminated PPC of going forward side by side in lattice misfit can not reduced device performance in fact by rotten growth (metamorphic growth).For example among another embodiment, second sandwich construction 32 can adopt InGaAsP or InGaP alloy, and has wideer or narrower energy gap than first active layer 133 and 134, so that absorbing light also is converted into photocarrier, the light that active layer absorbed of described photocarrier and annular piecemeal 51-54 has a different set of optical wavelength.Described embodiment is favourable for the application that the light by different wave length transmits light energy and data.
The PPC measurement result
[64] Fig. 9 be according to current-voltage (I-V) characteristic 301 of GaAs of the present invention base PPC50 and power output-voltage (P-V) characteristic 401 respectively with as current-voltage (I-V) characteristic 302 of the basic PPC of prior art condition GaAs and the comparison curves schematic diagram of energy conversion efficiency 402 among Fig. 1 and Fig. 2.It is that 830nm and luminous power are to finish under the light of 50mW the condition that device is shone that described measurement is to use optical wavelength.The maximum power transfer ratio that GaAs base PPC50 obtains according to the present invention is approximately 55%, and the power conversion rate of prior art energy converter is 45%, and the output voltage V when measuring OutBe approximately 6.3 volts and corresponding output current is approximately 4.5 milliamperes.According to transfer ratio and output current that GaAs according to the present invention base PPC 50 is obtained, GaAs base energy converter compared to existing technology approximately improves 25%, makes power conversion efficiency according to PPC of the present invention near theoretical maximum.Following factors is depended in described raising: the carbon doping of (1) p utmost point layer; This will improve the life-span at the minority carrier that contains 134 li at carbon doped p type emitter, the favourable direction of an electric field that the raising partly cause of described carrier lifetime is to be subjected to the superelevation doped layer of conductive layer 136 and the saturating window layer 135 of optional light to produce influences, be used for the migration of newborn photo-generated carrier in p-n junction so that bring out stronger electric field, and carbon doped layer has lower surface impedance, and described carbon doped layer comprises p type emission layer, p type window layer and p type conductive layer; Described lower surface impedance still can improve when electric current keeps very high can realize magnitude of voltage, and the lower surface impedance and the raising of voltage all will realize higher power output; (2) the geometric distributions shape of device piecemeal novelty is eliminated the cavity that is positioned at the device center by increasing the center piecemeal; And additional current barrier layer 131 significantly reduces even may eliminate any or all photoinduced conductivity at the adjacent sub interblock, and the reduction of described conductivity or elimination help to increase the voltage that each piecemeal produces under illumination condition.
[65] Figure 10 is according to current-voltage (I-V) characteristic 411 of InP base PPC of the present invention and the curve synoptic diagram of power output-voltage (P-V) characteristic 410, described InP base PPC contains first sandwich construction 30, and described first sandwich construction 30 contains InGaAs active layer 133/134 as indicated above and InP current barrier layer 131.The maximum power conversion efficiency of described device surpasses 28%, and output voltage is 3.5 volts when measuring, and the corresponding output current that obtains is 8.1 milliamperes.When the incident light wavelength is 1436 nanometers and power when being 100mW, the peak power output that can obtain PPC is approximately 28.4mW.For the light energy transducer of operating wavelength range between 1310-1550nm, high like this power conversion efficiency is significant improvement, and its performance parameter far surpasses all existing apparatus.Measured device has 9 fan-shaped device piecemeals.
[66] favourable part is, be can be used for the photoelectric energy technology according to one of crucial purpose of InP of the present invention base PPC, promptly increase the transmission range of light energy, make the transmission of described light energy have enough efficient to drive remote equipment as transducer and data-interface.When distance surpasses 1km, the necessary longwave optical of the scope of application between 1310nm to 1550nm, because utilize the described scope of the Optical Fiber Transmission light time in addition, the decling phase of described light is to higher.For short wavelength light, 980nm and following for example, the optical attenuation in optical fiber commonly used during transmission surpasses 3dB/km, and therefore, the equipment energy supply of surpassing hundreds of rice for distance will be under an embargo.Yet, when wavelength is 1310nm and above light when transmitting in optical fiber, therefore its optical attenuation is approximately 0.1dB/km or less than 0.1dB/km,, the distance that need transmit when light energy is 1km or when surpassing 1km, InP base PPC according to the present invention is more suitable for as energy converter than the GaAs based devices.Another favourable part is, can be installed in according to PPC of the present invention in the receiving element that is suitable for quasi-monomode fiber, therefore, uses InP base PPC according to the present invention can bring into play the advantage of teletransmission light energy.
[67] note, above-described specific embodiment according to photovoltaic power converter of the present invention can utilize the part technical characterictic of other embodiment, and only as example, can adopt the optional embodiment of a lot of elements in concrete application of the present invention, this is conspicuous for those skilled in the art.For example, other embodiment according to PPC of the present invention can contain the device piecemeal, described device piecemeal is with circular assembled arrangement, wherein first group of device piecemeal be positioned at the center and by second group of device piecemeal institute around, described second group of device piecemeal comprises at least two device piecemeals.Among the described here embodiment, first group of device piecemeal is made up of single center piecemeal 55, but in other embodiments, can predict, first group of described device piecemeal can be made of a more than device piecemeal, and described first group of device piecemeal has the additional trenches isolation and can connect or insulated from each other and addressing one by one.It is that the very device of n-doping is launched in the p-doping that other embodiment can contain base layer.In other embodiments, second sandwich construction that can also optimize the PPC core to be producing light, and can not contain intrinsic layer between second base layer and emission basic unit, maybe can make the contained intrinsic layer thickness that has less than 0.1 micron, so that form quantum well.
[68] certain, under the situation that does not break away from the spirit and scope of the present invention, can suppose other a large amount of embodiment.

Claims (19)

1, a kind of photovoltaic power converter comprises substrate, first sandwich construction, first current barrier layer, base stage electrical contact and emitter electrical contact, wherein:
Described substrate is made by semi-conducting material;
Described first sandwich construction is by described substrate support, and described first sandwich construction comprises first conductive layer of the semi-conducting material of first emitter layer of semi-conducting material of first base layer, second conduction type of the semi-conducting material of first conduction type and second conduction type; Described first base layer is positioned on the described substrate and has first forbidden band; Described first emitter layer is adjacent with described first base layer, described second conduction type and described first conductivity type opposite, thereby form first tie region between described first emitter layer and described first base layer, described first emitter layer has second forbidden band that is equal to or greater than described first forbidden band; Described first conductive layer is set on described first emitter layer, and described first conductive layer has any the 3rd forbidden band of being wider than in first and second forbidden bands;
Described first current barrier layer is made by the described second conductive type semiconductor material, and described first current barrier layer is between described substrate and described first sandwich construction;
Described base stage electrical contact is configured to be used for and the described first base layer electric connection;
Described emitter electrical contact is set on the described conductive layer, is used for and the described first emitter layer electric connection, thereby produces the relative voltage for described base stage electrical contact in response to the radiation of inciding the selected wavelength on described first emitter layer.
2, photovoltaic power converter according to claim 1 is characterized in that, the thickness of described current barrier layer is 0.1 μ m at least, and the doped level scope is 5 x 10 17To 1 x 10 19Cm -3
3, photovoltaic power converter according to claim 1 is characterized in that, also comprises the resilient coating of the first conductive type semiconductor material, and described resilient coating is configured between described current barrier layer and described first base layer.
4, photovoltaic power converter according to claim 1 is characterized in that, described first conduction type is the n type, and described second conduction type is the p type.
5, photovoltaic power converter according to claim 4 is characterized in that, described first emitter layer is that carbon mixes, thereby the acceptor doping range of concentrations is 2 x 10 18To 1 x 10 19Cm -3
6, photovoltaic power converter according to claim 4 is characterized in that, described first conductive layer and described first current barrier layer are doped carbon, thereby the acceptor concentration scope of described first conductive layer is 2 x 10 18To 2 x 10 19Cm -3, the acceptor doping concentration on the described first electrical conduction current barrier layer is 5 x 10 17Cm -3Or it is higher.
7, photovoltaic power converter according to claim 4 is characterized in that, the semi-conducting material of described substrate is GaAs.
8, photovoltaic power converter according to claim 7 is characterized in that, described first resilient coating, and the described semi-conducting material of base layer and emitter layer is GaAs.
9, photovoltaic power converter according to claim 8 is characterized in that, the described semi-conducting material of described conductive layer is a kind of alloy among AlGaAs and the InGaP.
10, photovoltaic power converter according to claim 9 is characterized in that, also comprises Al xGa (1-x)The Window layer of As alloy, wherein, x is greater than 50%, and described Window layer is between described first emitter layer and described first conductive layer.
11, photovoltaic power converter according to claim 7 is characterized in that, the described semi-conducting material of described first base layer and described emitter layer is a kind of alloy among InGaAs and the AlGaAs.
12, photovoltaic power converter according to claim 4 is characterized in that, described substrate, and the described semi-conducting material of described current barrier layer and described resilient coating is InP.
13, photovoltaic power converter according to claim 12 is characterized in that, the described semi-conducting material of described first base layer and described emitter layer is a kind of alloy among InGaAs and the AlGaAs.
14, photovoltaic power converter according to claim 12 is characterized in that, the described semi-conducting material of described conductive layer is a kind of alloy among InP and the InGaAsP.
15, photovoltaic power converter according to claim 1 is characterized in that, also comprises a plurality of grooves and a plurality of electric interconnector;
Described groove extends through described first sandwich construction and current barrier layer, and further extends partially into substrate, thereby forms the device piecemeal that separates on a plurality of spaces by described substrate support; Each described device piecemeal comprises first metal contact and second metal contact, described first metal contact is used for and the first interior base layer electric connection of device piecemeal, described first metal contact is set on first base layer in the opening of described first emitter layer, described second metal contact is set on the conductive layer of described device piecemeal, is used for and the described first emitter layer electric connection;
Described electric interconnector be used for each and only one first metal contact be electrically connected to the second adjacent separately metal contact, thereby form the device piecemeal chain that is connected in series, wherein, one first metal contact that is not connected in arbitrary second metal contact in described first metal contact is the base stage electrical contact, and one second metal contact that is not connected in arbitrary first metal contact in described second metal contact is the emitter electrical contact.
16, photovoltaic power converter according to claim 15 is characterized in that, the width of described groove is 5 μ m or littler.
17, photovoltaic power converter according to claim 15 is characterized in that, the degree of depth of described groove and the ratio of width are equal to or greater than 5.
18, photovoltaic power converter according to claim 4 is characterized in that,
The semi-conducting material of described substrate is that doped level is less than 10 15Cm -3Have a GaAs that intrinsic electricity is roughly led;
Described current barrier layer comprises the p-Doped GaAs, and the acceptor doping concentration range of described p Doped GaAs is at 5 x 10 17To 1 x 10 19Cm -3, thickness range is 0.1 to 0.3 μ m;
Described resilient coating comprises n-Doped GaAs p, and the donor doping concentration range of described n Doped GaAs is at 5 x 10 17To 2 x 10 18Cm -3, thickness range is 1 to 10 μ m;
Described first base layer comprises that GaAs and aluminium doping content are no more than a kind of in 35% the AlGaAs alloy, and its donor doping range of concentrations is 5 x 10 17To 1 x 10 19Cm -3, thickness range is 1 to 3 μ m;
Described first emitter layer comprises that GaAs and aluminium doping content are no more than a kind of carbon doped layer in 35% the AlGaAs alloy, and its thickness range is 0.6 to 1 μ m, and the acceptor doping concentration range is at 2 x 10 18To 5 x 10 18 cm -3And,
Described conductive layer is the p type, comprise following one of them: Zn or Be doping InGaAsP, be no more than 35% carbon doped with Al GaAs with the aluminium doping content, and the forbidden band of described first emitter and base layer is wider than in the forbidden band that has of described conductive layer, thickness range is 1 to 3 μ m, and the donor doping concentration range is 2 x 10 18To 2 x 10 19Cm -3
19, photovoltaic power converter according to claim 4 is characterized in that,
The semi-conducting material of described substrate is semi-insulating indium phosphate InP;
Described current barrier layer comprises that acceptor doping concentration is 5 x 10 17Cm -3Or higher p doping InP, thickness range is 0.2 to 0.3 μ m;
Described resilient coating comprises that donor doping concentration is 5 x 10 17Cm -3Or higher n doping InP, thickness range is 5 to 10 μ m;
Described first base layer comprises the InGaAs alloy with the InP lattice match, and its donor doping concentration is 5 x 10 17Cm -3Or higher, thickness range is 1 to 3 μ m;
Described first emitter layer comprises and the p doping InGaAs alloy of InP lattice match that its acceptor doping concentration is 2 x 10 18Cm -3Or higher, thickness range is 0.5 to 1.5 μ m; And,
Described conductive layer comprises that donor doping concentration is 2 x 10 18Cm -Or higher p doping InP, its thickness range is 1.5 to 2.5 μ m.
CN 200710301931 2006-12-20 2007-12-20 Photovoltaic power converter Pending CN101442079A (en)

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US60/871,108 2006-12-20
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11656420B2 (en) 2021-01-22 2023-05-23 Macleon, LLC System and method of distributing ultra high power using optical fiber cable

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11656420B2 (en) 2021-01-22 2023-05-23 Macleon, LLC System and method of distributing ultra high power using optical fiber cable
US11774695B2 (en) 2021-01-22 2023-10-03 Macleon, LLC Optical fiber cable

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