CN103022180B - X-radiation detector for CT system - Google Patents
X-radiation detector for CT system Download PDFInfo
- Publication number
- CN103022180B CN103022180B CN201210344540.2A CN201210344540A CN103022180B CN 103022180 B CN103022180 B CN 103022180B CN 201210344540 A CN201210344540 A CN 201210344540A CN 103022180 B CN103022180 B CN 103022180B
- Authority
- CN
- China
- Prior art keywords
- semi
- conducting material
- radiation detector
- work function
- materials
- 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.)
- Active
Links
- 239000000463 material Substances 0.000 claims abstract description 123
- 239000004065 semiconductor Substances 0.000 claims abstract description 72
- 150000001875 compounds Chemical class 0.000 claims abstract description 28
- 230000005855 radiation Effects 0.000 claims description 12
- 238000000151 deposition Methods 0.000 claims description 11
- 230000008021 deposition Effects 0.000 claims description 7
- 238000006243 chemical reaction Methods 0.000 claims description 6
- 238000005137 deposition process Methods 0.000 claims description 4
- 238000005530 etching Methods 0.000 claims description 4
- 239000004020 conductor Substances 0.000 claims description 2
- 238000005868 electrolysis reaction Methods 0.000 claims description 2
- 230000008020 evaporation Effects 0.000 claims description 2
- 238000001704 evaporation Methods 0.000 claims description 2
- 238000004544 sputter deposition Methods 0.000 claims description 2
- 239000002131 composite material Substances 0.000 claims 1
- 238000001514 detection method Methods 0.000 abstract description 6
- 239000010410 layer Substances 0.000 description 46
- 230000008859 change Effects 0.000 description 20
- 238000002591 computed tomography Methods 0.000 description 20
- 229910004613 CdTe Inorganic materials 0.000 description 14
- 239000011669 selenium Substances 0.000 description 12
- 239000000203 mixture Substances 0.000 description 11
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 11
- 239000002184 metal Substances 0.000 description 8
- 229910052751 metal Inorganic materials 0.000 description 8
- 230000010287 polarization Effects 0.000 description 8
- 238000005036 potential barrier Methods 0.000 description 7
- 230000002349 favourable effect Effects 0.000 description 6
- 230000007704 transition Effects 0.000 description 6
- 229910045601 alloy Inorganic materials 0.000 description 5
- 239000000956 alloy Substances 0.000 description 5
- 230000005611 electricity Effects 0.000 description 5
- 239000010931 gold Substances 0.000 description 5
- 238000005259 measurement Methods 0.000 description 5
- 229910052711 selenium Inorganic materials 0.000 description 5
- 229910052714 tellurium Inorganic materials 0.000 description 5
- 230000000694 effects Effects 0.000 description 4
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 4
- 229910052737 gold Inorganic materials 0.000 description 4
- 229910004611 CdZnTe Inorganic materials 0.000 description 3
- 229910052755 nonmetal Inorganic materials 0.000 description 3
- 229910052697 platinum Inorganic materials 0.000 description 3
- 238000005275 alloying Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000004907 flux Effects 0.000 description 2
- 230000005251 gamma ray Effects 0.000 description 2
- 238000009499 grossing Methods 0.000 description 2
- 238000007689 inspection Methods 0.000 description 2
- 238000005001 rutherford backscattering spectroscopy Methods 0.000 description 2
- 238000004804 winding Methods 0.000 description 2
- 229910000967 As alloy Inorganic materials 0.000 description 1
- 241000196324 Embryophyta Species 0.000 description 1
- 235000006508 Nelumbo nucifera Nutrition 0.000 description 1
- 240000002853 Nelumbo nucifera Species 0.000 description 1
- 235000006510 Nelumbo pentapetala Nutrition 0.000 description 1
- 229910001370 Se alloy Inorganic materials 0.000 description 1
- BUGBHKTXTAQXES-UHFFFAOYSA-N Selenium Chemical compound [Se] BUGBHKTXTAQXES-UHFFFAOYSA-N 0.000 description 1
- 229910001215 Te alloy Inorganic materials 0.000 description 1
- 230000005260 alpha ray Effects 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 210000001367 artery Anatomy 0.000 description 1
- 239000000969 carrier Substances 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 230000005684 electric field Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 238000003780 insertion Methods 0.000 description 1
- 230000037431 insertion Effects 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 239000011229 interlayer Substances 0.000 description 1
- 238000002372 labelling Methods 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 230000005012 migration Effects 0.000 description 1
- 238000013508 migration Methods 0.000 description 1
- 239000003960 organic solvent Substances 0.000 description 1
- 230000005622 photoelectricity Effects 0.000 description 1
- 238000000918 plasma mass spectrometry Methods 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 238000001004 secondary ion mass spectrometry Methods 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 239000002344 surface layer Substances 0.000 description 1
- PORWMNRCUJJQNO-UHFFFAOYSA-N tellurium atom Chemical compound [Te] PORWMNRCUJJQNO-UHFFFAOYSA-N 0.000 description 1
- 238000003325 tomography Methods 0.000 description 1
- 210000003462 vein Anatomy 0.000 description 1
- 239000002023 wood Substances 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01T—MEASUREMENT OF NUCLEAR OR X-RADIATION
- G01T1/00—Measuring X-radiation, gamma radiation, corpuscular radiation, or cosmic radiation
- G01T1/16—Measuring radiation intensity
- G01T1/24—Measuring radiation intensity with semiconductor detectors
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L31/02—Details
- H01L31/0224—Electrodes
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L31/08—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof in which radiation controls flow of current through the device, e.g. photoresistors
- H01L31/10—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof in which radiation controls flow of current through the device, e.g. photoresistors characterised by potential barriers, e.g. phototransistors
- H01L31/115—Devices sensitive to very short wavelength, e.g. X-rays, gamma-rays or corpuscular radiation
Landscapes
- General Physics & Mathematics (AREA)
- Physics & Mathematics (AREA)
- Power Engineering (AREA)
- Electromagnetism (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Computer Hardware Design (AREA)
- Engineering & Computer Science (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- Spectroscopy & Molecular Physics (AREA)
- Life Sciences & Earth Sciences (AREA)
- Molecular Biology (AREA)
- High Energy & Nuclear Physics (AREA)
- Health & Medical Sciences (AREA)
- Measurement Of Radiation (AREA)
- Electrodes Of Semiconductors (AREA)
- Light Receiving Elements (AREA)
Abstract
The present invention relates to a kind of X-radiation detector, X-radiation detector especially for CT system, it at least has the semi-conducting material of detection, preferred compound quasiconductor, and at least one Ohmic contact between semi-conducting material (HL) and contact material (KM), wherein semi-conducting material (HL) and contact material (KM) are respectively provided with carrier work function (WHL,WKM).It is a feature of the present invention that between semi-conducting material (HL) and contact material (KM), insert the intermediate layer being made up of intermediate materials (Z), wherein work function (the W of intermediate materials (Z)Z) it is positioned at the work function (W of semi-conducting material (HL)HL) and the work function (W of contact material (KM)KMBetween).Additionally, the present invention relates to a kind of CT system, which using X-radiation detector, it advantageously has at least one preferable Ohmic contact according to the present invention.
Description
Technical field
The present invention relates to a kind of directly converting x-rays radiation detector, straight especially for CT system
Connecing conversion X-radiation detector, it at least has the semi-conducting material of detection, preferred compound
Quasiconductor, and at least one Ohmic contact between semi-conducting material and contact material, the most partly lead
Body material and contact material are respectively provided with carrier work function.
Background technology
Scintillation detector or directly conversion semiconductor detector are used for detecting gamma ray and X-radiation,
Particularly in CT system and double-energy CT system.In scintillation detector, incident ray is by electricity
Son excites and is converted into photon and indirectly detects.At this based on semi-conducting material such as CdTe,
The direct transition detection device of CdZnTe, CdZnSe and CdZnTeSe can count single photon, thus
Direct detection ray.Here, the detector material of semiconducting winding is contacted by metal, such as by platinum or gold
The metal contact electrical conductivity ground of composition is connected with reading electronic equipment and the electric supply installation of detector.
These contacts are nonideal Ohmic contact.Preferable Ohmic contact between two kinds of different materials
The work function that feature essentially consists of bi-material is equal.In practice, this is relatively difficult to achieve, because
Less difference generally will cause injection contact or stop contact (injizierenden oder
Blockierenden Kontakten).For quasiconductor such as p-CdTe or p-CdZnTe that work function is bigger
Especially true.
But, Ohmic contact is the basic premise of photoelectricity resistance, as ray is such as being converted to electricity arteries and veins by it
When rushing, as namely used in the detector of directly conversion.Radiant flux is the biggest, and carrier is not
It is conveyed through SEMICONDUCTOR-METAL-interface with being obstructed the most important.
According to known in the art, the detector of directly conversion uses Schottky contacts
Or quasi-Ohmic contact (Schottky-Kontakt).Platinum or gold is used in this as metal.But,
When using these metals, the problem that operationally there will be polarization, i.e. due to the space electricity in quasiconductor
Lotus and cause internal electric field to change.Cause the most nonideal Ohmic contact of reason of described space charge.
Especially when high-level radiation, such as in CT (computer tomography), polarization strengthens and occurs.
The efficiency of detector is thus extremely limited.High radiation density thus can not directly and lossless
Be converted into electric pulse, thus use in CT system directly change semiconductor detector still can not be complete
Measurement result accurately is provided.
Summary of the invention
Therefore, the technical problem to be solved in the present invention be find a kind of for detecting directly turning of ionizing ray
Change the preferable Ohmic contact in detector, thus avoid effect that polarization causes and detector to fit
For high flow measurement.
Above-mentioned technical problem is solved by the feature of independent claims.The advantageous extension of the present invention be from
Belong to claimed subject matter.
Inventors have realised that can be by inserting as between metal and the quasiconductor of contact material
The intermediate layer being made up of intermediate materials produces preferable Ohmic contact on metal-semiconductor-interface.Pass through
This intermediate layer reduces work function and the work function differential of quasiconductor of contact material, even if this difference is in quasi-Europe
Nurse contact is also exist.
Intermediate layer is preferably made up of intermediate materials, and its work function is positioned at work function and the contact material of quasiconductor
Work function between.Thus reduce the potential barrier of interface and the difference of the work function of each adjacent materials,
Thus carrier more easily passes (ü berwindbar) interface.Intermediate layer is played a decisive role,
For each carrier classification that is slower and that therefore cause polarization, material has than quasiconductor (light
Electricity resistance) higher mobility.Thus these carriers " are aspirated " to interface quasiconductor-intermediate layer,
This means the reduction of polarization until being avoided.There is the carrier of opposite charges simultaneously from contact
Material through intermediate layer flow into quasiconductor and by with the group again of carrier slowly assembled there
Close and reduce space charge.The two process can be prevented effectively from space charge together and therefore reduce pole
Change effect.
Other different probability is there is for the enforcement in intermediate layer and the selection of intermediate materials.But
Being in all of embodiment, the work function of intermediate materials is positioned at work function and the quasiconductor of contact material
Between the work function of material.Intermediate materials is such as made up of the element of semi-conducting material or by being respectively provided with
The multiple different material layer of different work functions is constituted.Alternatively, intermediate layer is made up of intermediate materials,
This intermediate materials at least formed materials compounds in the near-surface region of quasiconductor.
Conventional deposition process, such as, sputter or evaporate and be applicable to intermediate materials is deposited on semi-conducting material
On.It is alternatively possible to etched semiconductor surface before deposition intermediate materials.
Basic thought is, by the new structure of non-ohm metal-semiconductor-contact, i.e. by gold
Belong to insertion intermediate layer between quasiconductor and form the Ohmic contact of non-obstruction.
Correspondingly, inventor propose a kind of directly converting x-rays inspection radiation and survey device, especially for
The direct converting x-rays radiation detector of CT system, its at least have detection semi-conducting material,
Preferred compound quasiconductor, and at least one ohm between semi-conducting material and contact material connects
Touching, wherein semi-conducting material and contact material are respectively provided with carrier work function, in order to improve, are partly leading
The intermediate layer being made up of intermediate materials, the wherein effusion of intermediate materials is inserted between body material and contact material
Merit is between the work function and the work function of contact material of semi-conducting material.
Utilize such direct converting x-rays radiation detector, though when high-level radiation,
CT (computer tomography) can also generate measurement result accurately.The efficiency of detector is by reducing or keeping away
Exempt from polarization and unrestricted.Therefore high radiation density can directly and without loss convert to electricity
Pulse.
The Favourable implementations of the Ohmic contact according to the present invention arranges such as platinum (Pt) or gold (Au) and makees
For contact material.As quasiconductor, it is advantageously that as compound semiconductor, such as can use CdTe-,
CdZnTe-, CdZnSe-or CdZnTeSe-semi-conducting material.
Below the different embodiments in intermediate materials and intermediate layer is illustrated.In all of embodiment
In, the work function of intermediate materials is between the work function and the work function of semi-conducting material of contact material.
The work function of the such as semiconductor CdTe work function less than contact material such as metal such as Pt, thus middle
The work function of material is less than the work function of contact material but is greater than the work function of quasiconductor.Alternatively, half
The work function of conductor is more than the work function of contact material.The situation of the quasiconductor of such as n doping.At this energy
Amount standard inverts, because being no longer the valence band (hole can move freely) of quasiconductor but quasiconductor
Point on the basis of conduction band (electronics can move freely).Doping level according to n doped semiconductor and post-treatment
(Nachprozessierung), such as In doping CdTe or CdZnTe for for semi-insulating
, i.e. the detector material of high resistant do not only exist p-type electric-conducting there is also N-shaped conduction.
The Favourable implementations in intermediate layer is, intermediate materials is compound semiconductor materials.Intermediate materials has
Nonmetal corresponding to compound semiconductor of profit ground.In such as in the case of CdTe compound semiconductor
Between material be nonmetal Te.
In another embodiment, it is nonmetallic that intermediate materials comes from compound semiconductor
The material of same main group in the cycle of element.In the case of such as CdTe compound semiconductor, as
Intermediate materials advantageously can come from the Se(selenium of the 6th main group) or Te(tellurium).
In the another embodiment in intermediate layer, intermediate materials is made up of at least two-layer, described two-layer by
At least two different materials forms.Implement two-layer, three layers or more layers the most in this embodiment.Logical
Crossing the material layer being respectively provided with different work functions, the work function from quasiconductor to contact material is with multiple less
Stage (Stufe) change.The layer constituted is the most, and the stage is the least, thus carrier will be easier to
Through each potential barrier at single interface.Additionally, the potential barrier at the stage more easily propagates through, then polarization
Effect is the least or is entirely avoided.The change programme of intermediate layer of material is such as to be made up of Te and Se
Alternating layer, its Pt as contact material and as the CdTe of semi-conducting material between.
Another kind of favourable embodiment is will to be deposited on by the materials compounds that at least two is elementary composition
On the surface of quasiconductor.At least two element advantageously acts as compound such as alloy deposition.One
Plant and implement change programme is provided with just two kinds of elements, be provided with many in other enforcement change programme
In two kinds such as three kinds or four kinds of elements.Each element of the composition of the compound of material, i.e. compound
Content so changes in the degree of depth in intermediate layer so that the stage between different work functions is the least.Little
Stage/potential barrier more easily passes as previously mentioned for carrier, thus greatly reduces polarization and make
Risk.In the change programme of this embodiment, forming with discrete Spline smoothing of compound,
Thus defined layer by have change piecemeal form and thus there is the compound of different work function
Constitute.In other change programme, composition is changed stepwise, thus work function also consecutive variations.Progressively
Change realizes linearly or the most non-linearly.Such as Se/Te alloy is applied on CdTe quasiconductor,
Wherein the material composition of this alloy with discrete step and can change continuously.
Near-surface region according to another embodiment, at least semi-conducting material and intermediate materials react with
And advantageously generate new material compound.The material compound formed by semi-conducting material and intermediate materials is right
The function in rear enforcement intermediate layer.At this, actually intermediate layer is made up of two-layer, actual original intermediate wood
Material and the new material compound generated by intermediate materials.In this embodiment, work function is the most piecemeal
It is changed.
Another kind of favourable embodiment is, etching semiconductor surface before depositing inter-layer, thus not
The most advantageously impurity on removing surface, and the removing at least semi-conducting material in near-surface region
One dvielement.The near surface layer so obtained is used as intermediate layer in a kind of change programme.Become at another kind
In change scheme, this layer is used as the extra play between intermediate materials and semi-conducting material.Favourable in this work function
Ground is changed piecemeal.
By intermediate layer, contact material, the particularly metal adhesiveness on semi-conducting material advantageously increases
By force.Intermediate materials deposition on semi-conducting material such as evaporates advantageous by deposition process, sputters,
Currentless deposition, electrolysis and/or chemical reaction realize.In a kind of favourable embodiment, deposition is borrowed
The combination helping at least two in deposition process mentioned above realizes.
Totally having according to embodiment of the present invention of direct converting x-rays radiation detector is following excellent
Gesture:
-polarization and hence in so that the high radiant flux of interface is reduced by forming Ohmic contact
Measurement is possibly realized, as used in CT (computer tomography).
-intermediate layer can be applied on semi-conducting material by conventional deposition method, such as by sputtering,
Evaporation etc..
Pulse measured by-reduction fuzzy, described pulse is similar Gaussian pulse shape and can be more
Simply it is further processed, such as in count electronics.
-Ohmic contact has the heat loss power less than non-ohmic contact, thus cools down institute about system
The cost needed is less.
-Ohmic contact be also used as CT (computer tomography)-, in X-ray-and gamma ray detector
Contact structures, and
Inspection and the checking of the composition of-contact can be analyzed by depth characteristic and measure with simple material
Realize, such as by secondary ion mass spectrometry (SIMS), energy dispersion X with the form of measurement of concetration
Alpha ray spectrum a (EDX), rutherford back scattering analysis (RBS) or inductivity coupled plasma mass spectrometry
(ICPMS).
Additionally belong to the scope of the invention also has CT system, can use X-ray in this CT system
Radiation detector, it comprises at least one detector element, advantageously at the detector material of semiconducting winding
And there is between contact material the preferable Ohmic contact according to the present invention, can be obtained by this CT system
To the tomography photo checking object.
Accompanying drawing explanation
Below by way of preferred embodiment, by accompanying drawing, the present invention will be described in more detail, the most only shows
Go out the feature necessary for understanding the present invention.Use the following drawings labelling: HL: semi-conducting material；
KM: contact material；WHL: the work function of semi-conducting material；WKM: the work function of contact material；
WZ: the work function of intermediate materials；Z: intermediate materials.
In accompanying drawing:
Fig. 1 to Fig. 4 respectively illustrates preferable ohm constructed according to the invention in various embodiments
The diagram of the work function of material during contact.
Detailed description of the invention
Fig. 1 to Fig. 4 respectively illustrates preferable ohm constructed according to the invention in various embodiments
The diagram of the different work functions of contact material KM, intermediate materials Z and semi-conducting material HL during contact.
It is that unit is work function W of eV and abscissa is position coordinates x on the vertical scale.Compound is partly led
Body CdTe and Pt metal are used separately as semi-conducting material HL and contact material KM.Semi-conducting material HL
It is respectively provided with carrier work function W with contact material KMHLAnd WKM, wherein work function WKMGreatly
In work function WHL。
Insert between semi-conducting material HL and contact material KM by intermediate materials Z group according to the present invention
The intermediate layer become.Further according to the present invention, work function W of intermediate materials ZZIt is positioned at semi-conducting material
Work function W of HLHLWork function W with contact material KMKMBetween.Fig. 1 to Fig. 4 draws respectively
It is divided into intermediate layer and the enforcement of intermediate materials Z.
In FIG, intermediate materials Z comes from and the week of the nonmetallic element in compound semiconductor
The material of the same main group of phase.The nonmetal of compound semiconductor is the Te from the 6th main group, middle
Material Z is correspondingly polycrystalline Se.According to the present invention, work function W of SeZIt is positioned at work function WHLWith
Work function WKMBetween.Polycrystalline Se is deposited on semiconductor CdTe (Cd1-xZnxTe, 0≤x≤1) upper product
Raw rich Se intermediate layer.In semi-insulating CdTe, work function W of SeZ(about 5.6 ± 0.3eV) omits
Micro-work function W more than semiconductor CdTeHL(5.4eV) and it is less than work function W of Pt simultaneouslyKM
(5.65eV), because carrier number is the least present in semi-conducting material HL so that it is only
The carrier that a small amount of impact produces due to ray such as X-ray.The additionally migration in the hole in polycrystalline Se
Rate 230cm2/ Vs is apparently higher than the mobility 50-80cm in CdTe2/Vs.Pass through alloying
(Einlegieren) or diffusion (Eindiffundieren) it is possible that the most by stages realize should
Transition.Such transition when room temperature be ohm and the gathering suppressing carrier at potential barrier and by
The contact produced in different work functions.
The intermediate materials Z in the intermediate layer of Fig. 2 and Fig. 3 is made up of the alloy of material Se and Te respectively.
Se-Te-intermediate layer is applied to semi-conducting material HL by deposition, is CdTe(Cd at this1-xZnxTe,
0≤x≤1) on.The content of the composition of alloy and two kinds of composition Se and Te changes in the intermediate layer.?
Than contacting with semi-conducting material HL on the side of the intermediate materials Z contacted with contact material KM
The alloy of richer Se is formed on side.Otherwise the side ratio correspondingly, contacted with semi-conducting material HL
Te richer with the side that contact material KM contacts.
According to the embodiment of Fig. 2, composition consecutive variations in the degree of depth in intermediate layer, thus each " layer "
Work function WZAlso consecutive variations and carrier can be easier to through each " potential barrier ".Continuous print line
The change of property is illustrated by solid line, and the nonlinear change of continuous print is shown by dashed lines.
According to Fig. 3, the composition of alloy, with discrete Spline smoothing, changes the most on segment-by-segment basis.This such as passes through
It is sequentially depositing each layer of realization with different composition.For each layer, by alloying or spread permissible
Realize transition the most by stages.So transition, as also show that in FIG, in room temperature
Time be ohm and suppress carrier to be gathered in potential barrier and produce due to different work functions
Contact.
When implementing the Ideal Ohmic Contact of Fig. 4, etch semi-conducting material HL, be CdTe at this
(Cd1-xZnxTe, 0≤x≤1) surface.The region of the near surface of the etching of semi-conducting material HL is rich
Te's.This makes to be easier to deposit Se or Te and its connection on the surface of semi-conducting material HL.
This richness Te layer defines the continuous transition formed corresponding to etch effects, and it plays the work such as intermediate layer
With (dashed region).Etching is such as realized by the organic solvent containing Br or I.In this embodiment
In, the intermediate materials Z being not inserted into adding in Ohmic contact is as single intermediate layer.Dotted line divides
Do not show the concentration change relying on each intermediate materials Z work function change, wherein this it can be appreciated that
Concentration curve, Cd is just contrary with Te.Two curves thus reflect the relative pass of Te with Cd
System.Closer to the surface of semi-conducting material HL, Te concentration is the biggest and Cd concentration is the least, and more
Going deep into semi-conducting material HL, Te concentration is the least and Cd concentration is the biggest.
Generally, invention proposes a kind of X-radiation detector, especially for CT system
X-radiation detector, its at least have detection semi-conducting material, preferred compound quasiconductor,
And at least one Ohmic contact between semi-conducting material and contact material, wherein semi-conducting material and
Contact material is respectively provided with carrier work function, to its further improvement, so that at semi-conducting material
And between contact material, insert the intermediate layer being made up of intermediate materials, wherein the work function of intermediate materials is positioned at
Between work function and the work function of contact material of semi-conducting material.
The present invention also show a kind of CT system, uses X-radiation detector in this CT system,
It advantageously has at least one preferable Ohmic contact according to the present invention.
Although the present invention is explained and illustrated in detail by preferred embodiment, but the present invention is not subject to
It is limited to disclosed example and those skilled in the art can thus obtain other change programme, and not
Depart from protection scope of the present invention.
Claims (10)
1. a direct converting x-rays radiation detector, it at least has:
1.1. the semi-conducting material detected, and
1.2. at least one Ohmic contact between semi-conducting material (HL) and contact material (KM),
Wherein
The most described semi-conducting material (HL) and described contact material (KM) are respectively provided with carrier ease
Go out merit (WHL,WKM), it is characterised in that
1.4. insert by intermediate materials between described semi-conducting material (HL) and contact material (KM)
(Z) intermediate layer formed, the work function (W of wherein said intermediate materials (Z)Z) it is positioned at described half
Work function (the W of conductor material (HL)HL) and the work function (W of described contact material (KM)KM)
Between, and the wherein said intermediate materials at least formed materialization in the near-surface region of quasiconductor
Compound.
2. according to the X-radiation detector described in the claims 1, it is characterised in that described
Intermediate materials (Z) is compound semiconductor materials.
3. according to the X-radiation detector described in the claims 1, it is characterised in that described
Intermediate materials (Z) is and the same main group of the nonmetallic period of element in described compound semiconductor
Material.
4., according to the X-radiation detector according to any one of the claims 1 to 3, it is special
Levying and be, described intermediate materials (Z) has at least two-layer being made up of at least two different materials.
5., according to the X-radiation detector according to any one of the claims 1 to 3, it is special
Levying and be, described intermediate materials (Z) is by having different work function (WZ1-WZ4) at least two
Elementary composition materials compounds.
6., according to the X-radiation detector according to any one of the claims 1 to 3, it is special
Levy and be, the side in the intermediate layer of the near-surface region of described semi-conducting material (HL) exists
The material compound being made up of described intermediate materials (Z) and described semi-conducting material (HL).
7., according to the X-radiation detector according to any one of the claims 1 to 3, it is special
Levy and be, the side in the intermediate layer of the near-surface region of described semi-conducting material (HL) is passed through
Etching removes the class atom in described semi-conducting material (HL).
8., according to the X-radiation detector according to any one of the claims 1 to 3, it is special
Levying and be, described intermediate layer is formed on the surface of described semi-conducting material (HL) by deposition process.
X-radiation detector the most according to claim 8, it is characterised in that described deposition
Method is evaporation, sputtering, currentless deposition, electrolysis and/or chemical reaction.
10. a CT system, it has according to the X according to any one of the claims 1 to 9
Ray radiation detector.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE201110083424 DE102011083424B3 (en) | 2011-09-26 | 2011-09-26 | Direct conversion X-ray detector for detecting X-ray in dual energy computer tomography-system, has intermediary layer whose electron affinity lies between electron affinities of semiconductor material and contact material |
| DE102011083424.9 | 2011-09-26 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN103022180A CN103022180A (en) | 2013-04-03 |
| CN103022180B true CN103022180B (en) | 2016-08-17 |
Family
ID=47425840
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201210344540.2A Active CN103022180B (en) | 2011-09-26 | 2012-09-17 | X-radiation detector for CT system |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN103022180B (en) |
| DE (1) | DE102011083424B3 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102012215041A1 (en) * | 2012-08-23 | 2014-02-27 | Siemens Aktiengesellschaft | Method for producing a semiconductor element of a direct-converting X-ray detector |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101521246A (en) * | 2008-02-05 | 2009-09-02 | 帕纳科有限公司 | Imaging detector |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FI20021255A (en) * | 2002-06-27 | 2003-12-28 | Metorex Internat Oy | X-ray direct detector based on direct conversion |
| FR2844918B1 (en) * | 2002-09-20 | 2005-07-01 | Commissariat Energie Atomique | PROCESS FOR PRODUCING ELECTRODES ON SEMI-CONDUCTOR MATERIAL TYPE II-VI OR A COMPOUND THEREOF |
-
2011
- 2011-09-26 DE DE201110083424 patent/DE102011083424B3/en active Active
-
2012
- 2012-09-17 CN CN201210344540.2A patent/CN103022180B/en active Active
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101521246A (en) * | 2008-02-05 | 2009-09-02 | 帕纳科有限公司 | Imaging detector |
Also Published As
| Publication number | Publication date |
|---|---|
| CN103022180A (en) | 2013-04-03 |
| DE102011083424B3 (en) | 2013-01-17 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US20240154049A1 (en) | Photovoltaic devices and method of making | |
| Jeong et al. | Ultraviolet-enhanced photodiode employing n-ZnO/p-Si structure | |
| Ievskaya et al. | Fabrication of ZnO/Cu2O heterojunctions in atmospheric conditions: Improved interface quality and solar cell performance | |
| US8778721B2 (en) | Array of mutually isolated, geiger-mode, avalanche photodiodes and manufacturing method thereof | |
| CN104737304B (en) | Photodiode array | |
| CN107658350B (en) | Photovoltaic device and manufacturing method | |
| Li et al. | The band alignment at CdS/Cu2ZnSnSe4 heterojunction interface | |
| US20120267746A1 (en) | Photo detector array of geiger mode avalanche photodiodes for computed tomography systems | |
| Kang et al. | n-ZnO: N/p-Si nanowire photodiode prepared by atomic layer deposition | |
| EP2323170A1 (en) | Electromagnetic radiation converter and a battery | |
| Park et al. | Spectral responsivity and quantum efficiency of n-ZnO/p-Si photodiode fully isolated by ion-beam treatment | |
| Jacopin et al. | Interplay of the photovoltaic and photoconductive operation modes in visible-blind photodetectors based on axial pin junction GaN nanowires | |
| Shasti et al. | Comparison of carrier transport mechanism under UV/Vis illumination in an AZO photodetector and an AZO/p-Si heterojunction photodiode produced by spray pyrolysis | |
| US20150295099A1 (en) | High work-function buffer layers for silicon-based photovoltaic devices | |
| JP5654425B2 (en) | Solar cell | |
| CN103022180B (en) | X-radiation detector for CT system | |
| CN105845746A (en) | Gamma irradiation scintillator detector based on silicon carbide PIN diode structure | |
| CN102956740B (en) | Detector element, radiation detector and there is the Medical Devices of such detector element and the method for the manufacture of detector element | |
| KR20140021730A (en) | Solar cell and manufacturing method thereof | |
| EP1391940B1 (en) | Semiconductor radiation detecting element | |
| KR101699380B1 (en) | Semiconductor radiation detecting device | |
| KR102101504B1 (en) | Carrier Selective Contact Silicon Solar Cell Having Capping Layer And Method For The Same | |
| Lee et al. | A novel method for crystalline silicon solar cells with low contact resistance and antireflection coating by an oxidized Mg layer | |
| KR20180079986A (en) | Solar cell | |
| CN106952968B (en) | Visible ray and ultraviolet selective light electric explorer |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| TR01 | Transfer of patent right | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20220126 Address after: Erlangen Patentee after: Siemens Healthineers AG Address before: Munich, Germany Patentee before: SIEMENS AG |