CN109518149B

CN109518149B - Preparation method of antimony selenide photoelectric film preferentially growing along (002) direction

Info

Publication number: CN109518149B
Application number: CN201910012399.8A
Authority: CN
Inventors: 陈世建; 周虹鹏; 冯孟磊; 张丁可
Original assignee: Chongqing University
Current assignee: Chongqing University
Priority date: 2019-01-07
Filing date: 2019-01-07
Publication date: 2020-11-20
Anticipated expiration: 2039-01-07
Also published as: CN109518149A

Abstract

The invention provides a rim<002>The preparation method of the antimony selenide photoelectric film with preferred direction growth comprises the following steps: (a) preparing a Mo/SLG conductive film: (b) preparing a rim on the basis of step (a)<003>Oriented antimony metal film Sb/Mo/SLG; (c) finally, the prepared Sb/Mo/SLG metal antimony film is put into a vacuum degree of 1 × 10^‑4‑9×10^‑4Pa quartz tube and adding Se according to the Se/Sb mass ratio of 1.5-3 to completely convert the antimony film into Sb₂Se₃(ii) a Then transferring the quartz tube to a muffle furnace for roasting treatment to obtain the edge<002>The antimony selenide photoelectric film grows preferentially in the direction. The antimony selenide film prepared by the method of the invention<002>The directional carrier has the highest mobility, so that the photoelectrochemistry hydrogen production efficiency can be greatly improved, and the photoelectrochemistry hydrogen production method has wide application potential in the field of photoelectrochemistry.

Description

Preparation method of antimony selenide photoelectric film preferentially growing along (002) direction

Technical Field

The invention belongs to the field of photoelectric material preparation, and particularly relates to a preparation method of an antimony selenide photoelectric film preferentially growing along a <002> direction.

Background

Antimony selenide (Sb)₂Se₃) Is a novel photoelectric material, has the forbidden band width of 1.1-1.2eV, is similar to silicon (Si), and has a very high absorption coefficient (10) compared with silicon⁵cm^-1Silicon is-10³cm^-1) And thus suitable as a thin film light absorbing material. The orthorhombic antimony selenide structure simultaneously has covalent bonds and Van der Waals bonds, and is a typical two-dimensional layered material. In the antimony selenide structure, Sb₄Se₆The basic structural units (called ribbon units in the following) extend infinitely in covalently bonded form along the c-axis and are formed from Sb along the a-axis and the b-axis₄Se₆Interconnected by weaker van der waals bondsAnd (4) connecting. Antimony selenide is therefore a highly anisotropic crystal structure, and thus the transport efficiency of charge carriers is also anisotropic. However, along the ribbon direction (c-axis, i.e. along the ribbon axis)<002>Direction) has the highest mobility, the transport capability along the other two axes is relatively weak, and along the ribbon direction (i.e., direction)<002>Direction) can greatly promote the photoelectrochemistry hydrogen production performance.

Therefore, the preparation of the antimony selenide photoelectric film which preferentially grows along the (002) direction has very important significance.

Disclosure of Invention

In view of the above-mentioned disadvantages of the prior art, it is an object of the present invention to provide a rim<002>The preparation method of the antimony selenide photoelectric film with preferred direction growth comprises the steps of utilizing Sb₂Se₃The growth rate is inherently anisotropic, and Sb (003) contributes to further suppressing Sb₂Se₃Film growth rate in other crystal orientation, and Sb pair under balanced selenium saturated vapor pressure₂Se₃The film is sintered, and the three materials are induced to produce the film with the highest carrier mobility<002>The antimony selenide film with preferred direction can greatly improve the photoelectrochemistry hydrogen production efficiency.

In order to achieve the purpose, the invention provides the following technical scheme: a preparation method of an antimony selenide photoelectric film preferentially growing along a <002> direction comprises the following steps:

(a) preparing a Mo/SLG conductive film:

(a1) ultrasonically cleaning the soda-lime glass substrate by acetone, alcohol and deionized water in sequence, soaking the soda-lime glass substrate in the alcohol, and drying the soda-lime glass substrate by a blower when the soda-lime glass substrate is used;

(a2) placing a metal molybdenum target in a magnetron sputtering chamber, wherein the purity of the metal molybdenum target is 99.99%;

(a3) loading the cleaned soda-lime glass substrate in the step (a1) on a substrate tray, transferring the substrate tray to a magnetron sputtering chamber with a metal molybdenum target, and vacuumizing to 1 × 10^-4-9×10^-4Pa, the distance between the molybdenum target and the soda-lime glass substrate is 3-10cm, and the substrate temperature is 250The temperature is 500 ℃ below zero, and the substrate rotates at the speed of 5A/s during sputtering so as to ensure the uniformity of a sample;

(a4) when the sputtering power is 100-200W, the double-layer molybdenum film structure is prepared by controlling the pressure of argon, firstly sputtering for 5-15min under the pressure of 2.0-3.5Pa of argon to obtain a first molybdenum layer with the thickness of 350-450nm, and then sputtering for 10-20min under the pressure of 0.15-0.30Pa of argon to obtain a second molybdenum layer with the thickness of 750-850 nm;

(b) preparing a Sb/Mo/SLG metal antimony film in <003> orientation on the basis of the step (a):

(b1) introducing N into the sputtering chamber₂Opening the sputtering chamber to atmospheric pressure, and replacing the metal molybdenum target with an antimony target, wherein the purity of the antimony target is 99.99%;

(b2) repeating the operation of the step (a 3);

(b3) sputtering under the conditions that the sputtering power is 30-100W and the argon is 0.25Pa, wherein the sputtering thickness of the antimony is about 300-1000 nm;

(c) finally, the rim prepared in step (b)<003>The oriented Sb/Mo/SLG metal film is put in a vacuum degree of 1X 10^-4Adding selenium into a Pa quartz tube according to the quantity ratio of Se/Sb of 1.5-3, so that an antimony film can be completely converted into Sb₂Se₃(ii) a Then transferring the quartz tube to a muffle furnace for roasting treatment to obtain the edge<002>The antimony selenide photoelectric film grows preferentially in the direction.

Further, in the step (a4), when the first molybdenum layer is 400nm, the sputtering power is 100W, the argon gas is 3.0Pa, and the sputtering time is 10min, and when the second molybdenum layer is 800nm, the sputtering power is 100W, the argon gas is 0.25Pa, and the sputtering time is 15 min.

Further, the amount ratio of Se/Sb species in step (c) is 2.

Further, in the step (c), the roasting temperature is 250-400 ℃, the heating rate is 5 ℃/min, and the sintering time is 2-8 h.

Further, the sintering temperature in the step (c) was 325 ℃.

Compared with the prior art, the invention has the following beneficial effects:

the invention utilizes Sb₂Se₃The material is self-contained in<002>The direction has a higher growth tendencySb aid<003>Contribute to further suppressing Sb₂Se₃The growth rate of the film in other crystal directions and the sintering in a sealed quartz tube are also beneficial to Sb₂Se₃Along the edge<002>A direction and height preferential growth is carried out to prepare an edge<002>The antimony selenide photoelectric film grows preferentially in the direction. The combined induction of the three components ensures that the antimony selenide film prepared by the method of the invention is coated on the surface of the substrate<002>The directional carrier has the highest mobility, so that the photoelectrochemistry hydrogen production efficiency can be greatly improved, and the photoelectrochemistry hydrogen production method has wide application potential in the field of photoelectrochemistry.

Drawings

FIG. 1 is a diagram showing the relationship between the growth direction of an antimony selenide film and carrier transport;

FIG. 2 is Sb₂Se₃Sb for growth<003>XRD spectrum of/Mo substrate;

FIG. 3 is an XRD spectrum of antimony selenide powder and an antimony selenide film prepared by the method of the invention;

FIG. 4 is an SEM image of a cross-section of an antimony selenide film prepared by the method of the invention;

FIG. 5 is Sb₂Se₃Macroscopic texture of the film;

FIG. 6 is an SEM image of the surface deposited platinum nanoparticles of an antimony selenide film prepared by the method of the invention;

FIG. 7 is a schematic diagram (a) and a structural diagram (b) of a manufactured photoelectrode of the present invention;

FIG. 8 is a linear voltammetric scan of a photoelectrochemical hydrogen production test using an antimony selenide film prepared by the method of the invention.

Detailed Description

The method of the present invention will be described in detail below with reference to specific examples and the accompanying drawings. The magnetron sputtering instrument adopted in the experiment is a pulsed laser deposition-magnetron sputtering composite system manufactured by a large connecting component. The target device is Cotelicaceae M2AM10, and the magnetron sputtering direct current power supply is Saiensis SI-DC 500C.

Firstly, preparation of Sb₂Se₃(002) /Mo/SLG antimony selenide film

Example 1

A preparation method of an antimony selenide photoelectric film preferentially growing along a <002> direction comprises the following steps:

(a) preparing a Mo/SLG conductive film:

(a1) ultrasonically cleaning the soda-lime glass substrate by acetone, alcohol and deionized water in sequence, taking out the clean glass substrate soaked in the alcohol, and drying by a blower when in use;

(a3) loading the cleaned soda-lime glass substrate in the step (a1) on a substrate tray, transferring the substrate tray to a magnetron sputtering chamber with a metal molybdenum target, and vacuumizing to 1 × 10^-4Pa, the distance between the molybdenum target and the soda-lime glass substrate is 10cm, the substrate temperature is 250 ℃, and the substrate rotates at the speed of 5A/s during sputtering to ensure the uniformity of the sample;

(a4) when the sputtering power is 100W, a double-layer molybdenum film structure is prepared by controlling the air pressure of argon, firstly a first molybdenum layer with the thickness of 350nm is obtained by sputtering for 5min under the condition that the argon is 3.5Pa, and then a second molybdenum layer with the thickness of 750nm is obtained by sputtering for 10min under the condition that the argon is 0.3 Pa;

(b2) repeating the operation of the step (a 3);

(b3) sputtering under the conditions that the sputtering power is 30W and the argon is 0.25Pa, wherein the sputtering thickness of antimony is 300 nm;

(c) finally, the rim prepared in step (b)<003>The oriented Sb/Mo/SLG metal film is put in a vacuum degree of 1X 10^-4Pa quartz tube and selenium at a Se/Sb mass ratio of 1.5, so that the antimony film can be completely converted to Sb₂Se₃(ii) a Then transferring the quartz tube to a muffle furnace for roasting treatment, wherein the roasting temperature is 250 ℃, the heating rate is 5 ℃/min, the sintering time is 2h, and the edge is obtained<002>Directionally preferential growth of antimony selenideAn optoelectronic film.

Example 2

(a) preparing a Mo/SLG conductive film:

(a3) loading the cleaned soda-lime glass substrate in the step (a1) on a substrate tray, transferring the substrate tray to a magnetron sputtering chamber with a metal molybdenum target, and vacuumizing to 4 × 10^-4Pa, the distance between the molybdenum target and the soda-lime glass substrate is 4cm, the substrate temperature is 250 ℃, and the substrate rotates at the speed of 5A/s during sputtering to ensure the uniformity of a sample;

(a4) when the sputtering power is 100W, a double-layer molybdenum film structure is prepared by controlling the air pressure of argon, firstly a first molybdenum layer with the thickness of 400nm is obtained by sputtering for 10min under the condition that the argon is 3.0Pa, and then a second molybdenum layer with the thickness of 800nm is obtained by sputtering for 15min under the condition that the argon is 0.25 Pa;

(b2) repeating the operation of the step (a 3);

(b3) sputtering under the sputtering power of 40W and the argon of 0.25Pa, wherein the sputtering thickness of antimony is 400 nm;

(c) finally, the rim prepared in step (b)<003>The oriented Sb/Mo/SLG metal film is put in a vacuum degree of 1X 10^-4Pa quartz tube and adding selenium according to the Se/Sb mass ratio of 2, so that the antimony film is completely converted into Sb₂Se₃(ii) a Then transferring the quartz tube to a muffle furnace for roasting treatment, wherein the roasting temperature is 325 ℃, the heating rate is 5 ℃/min, and the sintering time isFor 6h, obtain an edge<002>The antimony selenide photoelectric film grows preferentially in the direction.

Example 3

(a) preparing a Mo/SLG conductive film:

(a3) loading the cleaned soda-lime glass substrate in the step (a1) on a substrate tray, transferring the substrate tray to a magnetron sputtering chamber with a metal molybdenum target, and vacuumizing to 9 x 10^-4Pa, the distance between the molybdenum target and the soda-lime glass substrate is 3cm, the substrate temperature is 500 ℃, and the substrate rotates at the speed of 5A/s during sputtering so as to ensure the uniformity of a sample;

(a4) when the sputtering power is 200W, a double-layer molybdenum film structure is prepared by controlling the air pressure of argon, firstly a first molybdenum layer with the thickness of 450nm is obtained by sputtering for 15min under the condition that the argon is 2.0Pa, and then a second molybdenum layer with the thickness of 850nm is obtained by sputtering for 20min under the condition that the argon is 0.15 Pa;

(b2) repeating the operation of the step (a 3);

(b3) sputtering under the conditions that the sputtering power is 100W and the argon is 0.25Pa, wherein the sputtering thickness of antimony is 1000 nm;

(c) finally, the rim prepared in step (b)<003>The oriented Sb/Mo/SLG metal film is put in a vacuum degree of 1X 10^-4Pa quartz tube and selenium at a Se/Sb mass ratio of 1.5 to completely convert the antimony film to Sb₂Se₃(ii) a Then transferring the quartz tube to a muffle furnace for roasting treatment at a roasting temperatureThe temperature is 400 ℃, the heating rate is 5 ℃/min, the sintering time is 8h, and the edge is obtained<002>The antimony selenide photoelectric film grows preferentially in the direction.

II, Sb₂Se₃<002>Performance test of/Mo/SLG antimony selenide film

1. Growth direction of antimony selenide film

The growth direction of antimony selenide is closely related to the carrier transport efficiency. As shown in fig. 1, if the film is a ribbon cell with < hk0> parallel to the substrate surface, i.e., the growth direction, the transport efficiency of the film is lowest because carriers need to be transported by hopping among the van der waals bonds between the ribbons; if the film is grown along the c-axis, i.e., the ribbon cells are perpendicular to the substrate, the film will have the highest transport efficiency, since carriers are always transported along the covalent bond direction, and there will be higher mobility; if the growth direction is such that the ribbon is at an acute angle to the substrate, the transport efficiency is such that the larger the angle, the higher both are parallel growth, but the lower is c-axis growth.

2. X-ray diffractometer (XRD) testing

FIG. 2 is Sb₂Se₃Sb for growth<003>XRD spectrum of the/Mo substrate, from which Sb is known<003>Sb film in Mo<003>Has strong preferred orientation growth in the direction, which is beneficial to the growth of Sb in selenization₂Se₃Along the edge<002>And (4) directionally growing. FIG. 3 is an XRD spectrum of powdered antimony selenide and an antimony selenide film prepared by the method of the invention, from which powder Sb is known₂Se₃In that<002>The peak intensity of the direction is obviously weaker than that of Sb₂Se₃Film is on<002>Peak intensity of direction, which reflects that the film growth direction is along<002>Directionally grow and have very strong orientation because<002>The peaks are weaker in the non-oriented powder samples but become strongest in the preferentially oriented films, which is just as evidence of the successful synthesis of the height profile of the present invention<002>The antimony selenide photoelectric film grows preferentially.

3、Sb₂Se₃Macroscopic texture testing of thin films

FIG. 4 is Sb₂Se₃The texture test of the film can intuitively reflect the spatial distribution of preferred orientation. Sb can be seen from the figure₂Se₃The film indeed runs along the substrate normal<002>Oriented growth with the main growth distribution at an angle of 10 deg. to the substrate normal (see figure 1 for angle definition, corresponding to theta)>80 deg.) or less. This illustrates Sb₂Se₃The film being a height edge<002>Preferentially growing in the orientation.

4. Scanning Electron Microscope (SEM) testing

FIG. 5 is an SEM image of the cross section of an antimony selenide film prepared by the method of the invention, and it can be seen that molybdenum has a double-layer structure, and the film prepared by the molybdenum with the double-layer structure has better conductivity and stronger corrosion resistance; at the same time, Sb at the uppermost layer can be seen₂Se₃Good contact with the underlying deposited double layer of molybdenum helps the transport of carriers to the back electrode.

Application of antimony selenide photoelectric film preferentially growing along (002) direction in photoelectrochemistry hydrogen production

The prepared antimony selenide film with the c-axis preferentially growing is subjected to photoelectrochemistry hydrogen production performance test, firstly platinum nanoparticles which are beneficial to reducing water into hydrogen are deposited on the surface of the antimony selenide film, and the result is shown in figure 6, and as can be seen from an SEM (scanning electron microscope) image, the platinum nanoparticles which are clearly visible are arranged on the surface of the antimony selenide film; then, the antimony selenide film deposited with the platinum nano-particles is made into a photoelectrode material, and a manufactured photoelectrode material object diagram (a) and a photoelectrode structure diagram (b) are shown in figure 7; finally under the irradiation of standard sunlight (100 mW/cm)²) The photoelectrochemical hydrogen production performance test is carried out in 1mol/L sulfuric acid electrolyte, the result is shown in figure 8, and the graph shows that the photoelectrode manufactured by the antimony selenide film with c-axis preferred orientation growth has high hydrogen production photocurrent of 25.2mA/cm²This is mainly due to the fact that the antimony selenide film prepared by the invention has high c-axis preferred orientation growth and is along<002>The carriers in the direction have the highest mobility, so that the reaction is promoted, and the hydrogen production photocurrent is finally improved.

The reaction mechanism is as follows: this is mainly due toIn Sb₂Se₃The material itself has a higher growth tendency in the c-axis direction, and Sb<003>Contribute to further suppressing Sb₂Se₃The growth rate of the film in other crystal directions is that the Sb precursor film with preferred orientation is favorable for keeping the direction of the micro stress unchanged in the selenizing process, and the Sb film structure has a large pore channel structure which is favorable for Se to diffuse into the Sb film and react at the same time, so that Sb is finally enabled to grow₂Se₃Edge of<002>Growing in a direction and a height preferred mode; in addition, sintering in sealed quartz tubes is also beneficial to Sb₂Se₃Along the edge<002>The preferred growth direction is high, because the preferred growth is facilitated by keeping the saturation vapor pressure of Se constant during sintering, and the Se partial pressure is increased to promote the Se to diffuse to the Sb film at a lower reaction temperature and react to form antimony selenide.

Finally, the above embodiments are only for illustrating the technical solutions of the present invention and not for limiting, although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions may be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all of them should be covered in the claims of the present invention.

Claims

1. A preparation method of an antimony selenide photoelectric film preferentially growing along a <002> direction is characterized by comprising the following steps:

(a) preparing a Mo/SLG conductive film:

(a3) loading the cleaned soda-lime glass substrate in the step (a1) on a substrate tray, transferring the substrate tray to a magnetron sputtering chamber with a metal molybdenum target, and vacuumizing to 1 × 10^-4-9×10^-4Pa, the distance between the molybdenum target and the soda-lime glass substrate is 3-10cm, and the substrate temperature is 250-50 DEGThe substrate is rotated at the speed of 5A/s during sputtering at 0 ℃ to ensure the uniformity of the sample;

(b2) repeating the operation of the step (a 3);

(b3) sputtering under the conditions that the sputtering power is 30-100W and the argon is 0.25Pa, wherein the sputtering thickness of the antimony is 300-1000 nm;

(c) finally, the rim prepared in step (b)<003>The oriented Sb/Mo/SLG metal film is put in a vacuum degree of 1X 10^- ⁴Adding selenium into a Pa quartz tube according to the quantity ratio of Se/Sb of 1.5-3, so that an antimony film can be completely converted into Sb₂Se₃(ii) a And then transferring the quartz tube to a muffle furnace for roasting treatment, wherein the roasting temperature is 250-400 ℃, the heating rate is 5 ℃/min, the sintering time is 2-8 h, and the edge is obtained<002>The antimony selenide photoelectric film grows preferentially in the direction.

2. The method of claim 1, wherein the sputtering power of the first molybdenum layer of 400nm in step (a4) is 100W and the sputtering power of argon gas is 3.0Pa for 10min, and the sputtering power of the second molybdenum layer of 800nm is 100W and the sputtering power of argon gas is 0.25Pa for 15 min.

3. The method of claim 1, wherein the amount ratio of Se/Sb species in step (c) is 2.

4. The method of claim 1, wherein the sintering temperature in step (c) is 325 ℃.