CN102605340B - A kind of P-type doped ZnxCd1-xS nanometer material and preparation method thereof - Google Patents

Abstract

Translated fromChinese

本发明公开了一种P型掺杂Zn_xCd_1-xS纳米材料及其制备方法，本发明采用化学气相沉积法和气-液-固生长机制，在合成过程中原位掺杂Ag、Cu、N、P等元素进行p型掺杂制备p型掺杂Zn_xCd_1-xS纳米材料，通过调节蒸有10nm金薄膜的硅片的位置，可以得到不同组分的Zn_xCd_1-xS纳米材料。本发明P型掺杂Zn_xCd_1-xS纳米材料具有成分可调，电导率可控的特点。The invention discloses a P-type doped Zn_x Cd_1-x S nanomaterial and a preparation method thereof. The invention adopts a chemical vapor deposition method and a gas-liquid-solid growth mechanism, and in-situ doping of Ag, Cu, N, P and other elements are p-type doped to prepare p-type doped Zn_x Cd_1-x S nanomaterials, and Zn_x Cd_1-x with different components can be obtained by adjusting the position of the silicon wafer evaporated with a 10nm gold film S nanomaterials. The P-type doped Zn_x Cd_1-x S nanometer material of the invention has the characteristics of adjustable composition and controllable electrical conductivity.

Description

A kind of P type doping of Zn xCd 1-xS nano material and preparation method thereof

One, technical field

The present invention relates to a kind of nano material and preparation method thereof, specifically a kind of P type doping of Zn_xCd_1-xS nano material and preparation method thereof.

Two, background technology

II-VI family broad stopband one dimension semiconductor material becomes current study hotspot because of it in the potentiality aspect the nanometer optical device.Because nano material has quantum size effect and large surface-volume ratio, make light, electricity, magnetic, machinery and the chemical property of nano material and body material that obvious difference be arranged.

Ternary alloy II-VI family nano material is by regulating the ratio of various components, can so that the optical property of material modulated.Direct band-gap semicondictor material Zn_xCd_1-xS, energy gap can change between 2.42ev-3.66ev, and its emission wavelength can change between 335nm-512nm accordingly, therefore in application facet such as heterojunction luminescent device, solar cell and photoconductive devices, very large potentiality is arranged.But, up to the present, to ternary alloy nano material Zn_xCd_1-xSynthetic, the doping of S and the research of performance are still seldom.

Three, summary of the invention

The present invention aims to provide a kind of P type doping of Zn_xCd_1-xS nano material and preparation method thereof, technical problem to be solved are to provide the P type doping of Zn that a kind of preparation method is simple, composition is adjustable and specific conductivity is controlled_xCd_1-xThe S nano material.

The growth technique that nano material of the present invention adopts is chemical Vapor deposition process (CVD), and theoretical foundation is gas-liquid-solid (VLS) growth mechanism.Adopt the method for high temperature thermal evaporation, doped source, Cadmium Sulfide (CdS) and zinc sulphide (ZnS) are become steam, steam the small-particle that golden film at high temperature becomes gold on the silicon chip in downstream simultaneously, when carrier gas is transported to silicon chip place, downstream with bulk material, material can be deposited in the particle of gold, just have bulk material and separate out after gold grain is saturated, thereby prepare P type doping of Zn_xCd_1-xThe S nano material.

Technical solution problem of the present invention adopts following technical scheme:

P type doping of Zn of the present invention_xCd_1-xThe S nano material is characterized in that: 0＜x＜1; The doped source of P type doping is selected from Ag₂S, CuS, NH₃, PH₃In one or more.

P type doping of Zn of the present invention_xCd_1-xS preparations of nanomaterials method is as follows:

Take Cadmium Sulfide powder, zinc sulfide powder and solid doped source by proportional quantity, zinc sulfide powder is placed in porcelain boat No. one, a described porcelain boat is placed in the heating source place of tube furnace; Cadmium Sulfide powder and solid doped source mixed grinding are placed in No. two porcelain boats, described No. two porcelain boats are placed in the heating source place of tube furnace and the upstream that described No. two porcelain boats are positioned at a porcelain boat; To steam the gold silicon sheet and be placed in 10-14cm place, heating source downstream, and pass into argon hydrogen mixture in body of heater, in stove, pressure is 1.35 * 10³Pa, tube furnace begins to heat up subsequently, controls the heating source temperature and is 1000 ℃ and is incubated 2 hours, obtains P type doping of Zn after naturally cooling to room temperature_xCd_1-xThe S nano material;

Described solid doped source is selected from Ag₂S and/or Cu₂S, doping is the 2-10% of Cadmium Sulfide powder and zinc sulfide powder total mass, if ratio is any when multiple.

The purity of described zinc sulfide powder, Cadmium Sulfide powder and solid doped source 〉=99.99%.

The flow velocity of argon hydrogen gas mixture is 30sccm, and argon hydrogen volume ratio is 95: 5.

Temperature rise rate when tube furnace heats up is 20 ℃/min.

P type doping of Zn of the present invention_xCd_1-xS preparations of nanomaterials method is as follows:

Take Cadmium Sulfide powder and zinc sulfide powder and ground and mixed by proportional quantity and get compound, compound is placed in porcelain boat and described porcelain boat and steaming gold silicon sheet are put into tube furnace, porcelain boat is positioned at the heating source place, steam the gold silicon sheet and be positioned at 10-14cm place, heating source downstream, pass into argon hydrogen mixture and gas doped source in body of heater, in stove, pressure is 1.35 * 10³Pa, porcelain boat place are warming up to 1000 ℃ and be incubated 2 hours, obtain P type doping of Zn_xCd_1-xThe S nano material;

Described gas doping source is selected from NH₃And/or PH₃

The purity of described Cadmium Sulfide powder and zinc sulfide powder 〉=99.99%.

The flow velocity of argon hydrogen gas mixture is 50sccm, and argon hydrogen volume ratio is 95: 5.

Temperature rise rate when tube furnace heats up is 20 ℃/min.

The flow velocity in described gas doping source is 40-60sccm.

Concrete preparation process is as follows when doped source is gas:

1, take respectively the zinc sulfide powder of purity 〉=99.99% and the Cadmium Sulfide powder of purity 〉=99.99% by proportional quantity, add in porcelain boat after ground and mixed.Porcelain boat and steaming gold silicon sheet are put into a silica tube in order, then it is inner that this silica tube is put into the tubular type body of heater.Concrete position is: porcelain boat is positioned at the heating source place, steams the gold silicon sheet and is positioned at heating source downstream 10-14 centimeters.

2, before heating, first logical protection gas argon gas (Ar) cleans the silica tube of tube furnace, clean complete after, silica tube is vacuumized (1 * 10^-3Pa is following), the flow velocity with 50sccm leads to Ar/H simultaneously₂(Ar:95%, H₂: the 5%) flow velocity of gas mixture and 40-60sccm ventilation body doped source, keep air pressure 1.35 * 10³The Pa left and right, the speed that heating source is sentenced 20 ℃/min rises to 1000 ℃, is incubated 2 hours, naturally cools to room temperature, can obtain P type doping of Zn_xCd_1-xThe S nano material.

Concrete preparation process is as follows when doped source is solid:

1, the zinc sulfide powder that takes purity 〉=99.99% by proportional quantity is put into porcelain boat No. one, takes the Cadmium Sulfide powder of purity 〉=99.99% and the silver sulfide powder of purity 〉=99.99% and puts into porcelain boat No. two.Two porcelain boats and steam the silica tube that gold silicon sheet (Au thickness is 10nm) is put into tube furnace in order make a porcelain boat and No. two porcelain boats be positioned at place, diamond heating source, and No. two porcelain boats are positioned at the upstream of a porcelain boat; Steam the gold silicon sheet and be positioned at 10-14cm place, heating source downstream.

2, before heating, first logical protection gas argon gas (Ar) cleans the silica tube of tube furnace, clean complete after, silica tube is vacuumized (1 * 10^-3Pa is following), the flow velocity with 30sccm leads to Ar/H simultaneously₂(Ar:95%, H₂: 5%) gas mixture, keep air pressure 1.35 * 10³The Pa left and right, the speed that heating source is sentenced 20 ℃/min rises to 1000 ℃, is incubated 2 hours, naturally cools to room temperature, can obtain P type doping of Zn_xCd_1-xThe S nano material.

The P type doping of Zn of synthesizing in order to detect_xCd_1-xThe electrical properties of S nano material is mainly its bottom gate fieldtron of preparation, and this need to select suitable electrode materials and P type doping of Zn_xCd_1-xThe S nano material forms good ohmic contact.P-shaped material and high-work-function metal easily form ohmic contact, form Schottky contacts with low workfunction metal.So the electrode materials that the present invention selects when the test electrical properties is Precious Metals-Gold (Au), its work function is 5.1eV.The P type doping of Zn that specifically according to a conventional method the present invention is prepared_xCd_1-xThe S nano material is distributed on the titanium dioxide silicon chip, prepares electrode pattern by ultraviolet photolithographic on the titanium dioxide silicon chip, adopts subsequently electron beam evaporation process to prepare gold electrode, described gold electrode and P type doping of Zn of the present invention_xCd_1-xThe S nano material forms ohmic contact, thereby obtains source-drain electrode, then consists of fieldtron with the Cu gate electrode.

The P type doping of Zn of synthesizing in order to detect_xCd_1-xThe S nano material, the present invention adopts field emission scanning electron microscope (FESEM), energy dispersion x-ray spectrometer (EDX) and X-ray diffraction (XRD) to P type Zn_xCd_1-xThe S nano material is carried out structural characterization, to P type Zn_xCd_1-xWhat S nano material device electrical performance testing adopted is the 4200-SCS N-type semiconductorN ability meter that U.S. Keithley company produces.

Compared with the prior art, beneficial effect of the present invention is embodied in:

1, Technology proposed by the invention is the synthetic Zn of single stage method_xCd_1-xS ternary alloy nano material, simple to operate.

2, the equipment that relates in the present invention is simple, and reasonable price is suitable for scale operation.

3, the present invention steams the position of gold silicon sheet by adjusting, namely changes base reservoir temperature, can obtain the doping of Zn of different components_xCd_1-xThe S nano material has realized that composition is adjustable.

4, the adulterating method of using in the present invention is also very simple, economical, is integrated into a step with material is synthetic, and can obtains the nano material of different specific conductivity by the atomic percentage conc of regulating hotchpotch, has realized the control to specific conductivity.

Four, description of drawings

Fig. 1 nano material of the present invention SEM figure.Can find out in Fig. 1 that synthetic nano material length has the 60-100 micron.

The XRD figure of Fig. 2 nano material of the present invention.

Fig. 3 is the EDX figure of the nano material for preparing of the present invention.(a) corresponding embodiment 1 wherein, (b) corresponding embodiment 2, (c) corresponding embodiment 3, (d) corresponding embodiment 4.Relatively (a), (b), (c), (d) four figure can find, in synthetic nano material, the content of Zn, Cd is changing, and has realized P type doping of Zn_xCd_1-xConstituent adjustment in the S nano material.

Fig. 4 is the drain-source current-drain-source voltage curve of the different levels of doping nano material for preparing of the present invention.The corresponding embodiment 1 of A curve wherein, thecorresponding embodiment 5 of B curve, the corresponding embodiment 6 of C curve.The slope of A, B, the C curve namely specific conductivity of corresponding embodiment has obvious difference, and is to control the variation of specific conductivity by changing doping, so realized that specific conductivity is controlled.

Fig. 5 is the drain-source current of fieldtron under different grid voltages that utilize nano material of the present invention preparation-drain-source voltage curve.Shown in illustration is gate source voltage-drain-source current curve when drain-source voltage is 1V.As can be seen from Figure 5 along with the increase of grid voltage, source-drain current is reducing, and shows that synthetic nano material is the P type.Simultaneously illustration also should be just this fact.By this can prove successful realization P type doping.

Five, embodiment

Embodiment 1:

1, the zinc sulfide powder that takes 0.1 gram purity 〉=99.99% is put into porcelain boat No. one, takes the Cadmium Sulfide powder of 0.15 gram purity 〉=99.99% and the silver sulfide powder of 0.01 gram purity 〉=99.99% and puts into porcelain boat No. two.Two porcelain boats and steam the silica tube that gold silicon sheet (Au thickness is 10nm) is put into tube furnace in order make a porcelain boat and No. two porcelain boats be positioned at place, diamond heating source, and No. two porcelain boats are positioned at the upstream of a porcelain boat; Steam the gold silicon sheet and be positioned at 10-11cm place, heating source downstream.Upstream, downstream are distinguished with gas flow.

2, before heating, first logical protection gas argon gas (Ar) cleans the silica tube of tube furnace, clean complete after, silica tube is vacuumized (1 * 10^-3Pa is following), the flow velocity with 30sccm leads to Ar/H simultaneously₂(Ar:95%, H₂: 5%) gas mixture, keep air pressure 1.35 * 10³The Pa left and right, the speed that heating source is sentenced 20 ℃/min rises to 1000 ℃, is incubated 2 hours, naturally cools to room temperature, can obtain P type doping of Zn_0.8Cd_0.2The S nano material.

Embodiment 2:

The present embodiment is identical with embodiment 1 preparation method, and different is that the position of steaming the gold silicon sheet is adjusted into heating source downstream 11-12cm, can obtain P type doping of Zn_0.6Cd_0.4S。

Embodiment 3:

The present embodiment is identical with embodiment 1 preparation method, and different is that the position of steaming the gold silicon sheet is adjusted into heating source downstream 12-13cm, can obtain P type doping of Zn_0.4Cd_0.6S。

Embodiment 4:

The present embodiment is identical with embodiment 1 preparation method, and different is that the position of steaming the gold silicon sheet is adjusted into heating source downstream 13-14cm, can obtain P type doping of Zn_0.1Cd_0.9S。

Embodiment 5:

The present embodiment is identical with embodiment 1 preparation method, and the quality of different is silver sulfide powder is 0.02 gram.

Embodiment 6:

The present embodiment is identical with embodiment 1 preparation method, and the quality of different is silver sulfide powder is 0.05 gram.

Claims (6)

1. P type doping of Zn_xCd_1-xS preparations of nanomaterials method is characterized in that:

Press Zn_xCd_1-xThe proportional quantity that the S chemical formula limits takes Cadmium Sulfide powder, zinc sulfide powder and solid doped source, and 0＜x＜1 is placed in porcelain boat No. one with zinc sulfide powder, a described porcelain boat is placed in the heating source place of tube furnace; Cadmium Sulfide powder and solid doped source mixed grinding are placed in No. two porcelain boats, described No. two porcelain boats are placed in the heating source place of tube furnace and the upstream that described No. two porcelain boats are positioned at a porcelain boat; To steam the gold silicon sheet and be placed in 10-14cm place, heating source downstream, and pass into argon hydrogen mixture in body of heater, in stove, pressure is 1.35 * 10³Pa, tube furnace begins to heat up subsequently, controls the heating source temperature and is 1000 ℃ and is incubated 2 hours, obtains P type doping of Zn after naturally cooling to room temperature_xCd_1-xThe S nano material;

Described solid doped source is selected from Ag₂S and/or Cu₂S, doping is the 2-10% of Cadmium Sulfide powder and zinc sulfide powder total mass;

The flow velocity of described argon hydrogen gas mixture is 30sccm, and the argon hydrogen volume is than being 95:5.

2. preparation method according to claim 1, is characterized in that: the purity of described zinc sulfide powder, Cadmium Sulfide powder and solid doped source 〉=99.99%.

3. preparation method according to claim 1 is characterized in that: the temperature rise rate when tube furnace heats up is 20 ℃/min.

4. P type doping of Zn_xCd_1-xS preparations of nanomaterials method is characterized in that:

Press Zn_xCd_1-xThe proportional quantity that the S chemical formula limits takes Cadmium Sulfide powder and zinc sulfide powder and ground and mixed and gets compound, 0＜x＜1, compound is placed in porcelain boat and described porcelain boat and steaming gold silicon sheet are put into tube furnace, porcelain boat is positioned at the heating source place, steam the gold silicon sheet and be positioned at 10-14cm place, heating source downstream, pass into argon hydrogen mixture and gas doped source in body of heater, in stove, pressure is 1.35 * 10³Pa, porcelain boat place are warming up to 1000 ℃ and be incubated 2 hours, obtain P type doping of Zn_xCd_1-xThe S nano material;

Described gas doping source is selected from NH₃And/or PH₃, the flow velocity in described gas doping source is 40-60sccm;

The flow velocity of described argon hydrogen gas mixture is 50sccm, and the argon hydrogen volume is than being 95:5.

5. preparation method according to claim 4, is characterized in that: the purity of described Cadmium Sulfide powder and zinc sulfide powder 〉=99.99%.

6. preparation method according to claim 4 is characterized in that: the temperature rise rate when tube furnace heats up is 20 ℃/min.

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