CN101824601A

CN101824601A - Method for preparing Cu2SixSn1-xS3 photovoltaic film

Info

Publication number: CN101824601A
Application number: CN201010164446A
Authority: CN
Inventors: 刘萍
Original assignee: Shenzhen Danbang Investment Group Co Ltd
Current assignee: Shenzhen Danbang Investment Group Co Ltd
Priority date: 2010-05-06
Filing date: 2010-05-06
Publication date: 2010-09-08

Abstract

The invention provides a method for preparing a Cu2SixSn1-xS3 photovoltaic film. In the method, mixed gas of hydrogen sulfide and argon gas is used as sputtering gas, a Cu-Si-Sn alloy target is used as a cathode target, and a magnetic control reaction sputtering mode is adopted for film sedimentation, wherein the atomic ratio of components Cu, Si and Si of the alloy target is 1:0.1-2:0.1-2, the pressure in a sputtering room is 0.05 to 10Pa while sputtering, the distance between a target material and a substrate is 3 to 15 centimeters, the sputtering power of the cathode target is 15 to 300W, the substrate temperature is between 20 and 700 DEG C, the substrate rotates at a speed of 0 to 1,000 revolutions per minute, and the thickness of the grown film is 0.2 to 5mu m. The film prepared by the method has the advantages of good uniformity of components in large areas, high crystallization quality, low content of the second phase, and excellent optical property and electrical property; and the method has the advantages of simple process, low cost, good reproducibility and the like, which are not possessed by the conventional thermal activation technology.

Description

A kind of Cu 2Si xSn 1-xS 3The preparation method of photovoltaic film

Technical field

The invention belongs to the photoelectric material technical field of new energies, relate to a kind of compound semiconductor film---Cu as thin film solar cell light absorption layer ₂Si _xSn _1-xS ₃The preparation method of photovoltaic film.

Background technology

The development solar cell is to solve the energy dilemma go from bad to worse and the effective way of environmental pollution.In all kinds of solar cells, CuIn _1-xGa _xSe ₂(CIGS) thin film solar cell is considered to one of solar cell of most important and tool development prospect with its good photovoltaic property.Yet, CuIn _1-xGa _xSe ₂In in the compound, Ga and Se are dissipated metals, cost an arm and a leg and reserves limited.Therefore, seek contain the high abundance element and cheaply the light absorbing zone thin-film material substitute CuIn _1-xGa _xSe ₂Become the important topic of pendulum in face of us.It must be noted that in order to realize the large-scale practical application of solar cell, light absorption layer material is except requiring low cost, starting material have obtained, also should possess can and CuIn _1-xGa _xSe ₂Comparable premium properties comprises: suitable (1.2～1.5eV) and adjustable band gap, bigger photoabsorption coefficient in the visible-range, high electronic mobility particularly has electricity tolerance etc. preferably to defective and crystal boundary.

The more equivalent material of research is the Cu that substitutes 1 In atom with 0.5 II family (Zn) atom and 0.5 IV family (Sn) atom at present ₂ZnSnS ₄(CZTS).Yet in this material preparation process, except needs control Cu/ (Zn+Sn) atom proportioning, the more important thing is must strict control Zn/Sn atom proportioning.This is because Zn ²⁺And Sn ⁴⁺Non-equivalence, the electric property of material is very responsive to Zn/Sn atom proportioning, and when existing very small stoichiometry to depart from, the trace second that is produced will make the transformation efficiency of device descend rapidly mutually.

Another kind of replacement mode promptly adopts 1/3 I B family atom (Cu) and 2/3 IVA family atom (Si, Ge or Sn) to replace the Cu of 1 In atom ₂MS ₃(be Cu (Cu _1/3M _2/3) S ₂, M is Si, Ge or Sn) series compound in Cu ₂SixSn _1-xS ₃(being called for short CSTS) then can avoid the problems referred to above preferably.Because Si ⁴⁺And Sn ⁴⁺Be that equivalence of the same clan substitutes, can not cause the generation of residual electric charge, just as the Ga among the CIGS ³⁺Part substitutes In ³⁺, different x values not only can not cause tangible disadvantageous effect to the material electric property, can adjust the band gap width of material on the contrary or form gradient band gap, is convenient to absorb more fully sunlight.In addition, because Cu ₂SnS ₃And Cu ₂SiS ₃Band gap width be respectively 0.93eV and 2.48eV, so Cu ₂Si _xSn _1-xS ₃Band gap width should in 0.93～2.48eV scope, include the best band gap width of solar cell material.Therefore, such material has a good application prospect in solar cell.

At present, for compound film, sulfide semiconductor film particularly, one all is to adopt the technology based on thermal activation to prepare, promptly realize the reaction between each constituent element and form required compound film, mainly comprise evaporation and two kinds of technological lines of preformed layer postcure by heat.Wherein the film quality of evaporation preparation is higher, and is poor but the development bottleneck of this technology maximum is a large-area uniformity, is difficult to obtain practical application.The preformed layer postcure is to adopt methods such as sputter, plating to prepare the alloy preformed layer earlier, and then preformed layer heat-treated (sulfuration), obtain the target sulfide film, this method is easy to realize the large-area preparation of film, but has problems such as complex process, long flow path, circulation ratio be bad.Therefore, in order to realize the large-scale application of thin film solar cell, development one step preparation big area, high quality Cu ₂Si _xSn _1-xS ₃The method of film is necessary.

Summary of the invention

The objective of the invention is: an a kind of step acquisition big area and high quality Cu that be easy to is provided ₂Si _xSn _1-xS ₃The deposition technique of photovoltaic film.

To achieve these goals, technical scheme of the present invention is:

A kind of Cu ₂Si _xSn _1-xS ₃The preparation method of photovoltaic film is characterized in that: described preparation method as sputter gas, as the negative electrode target, carries out the growth in situ of film with the Cu-Sin-Sn alloys target with hydrogen sulfide and argon gas mixed gas in the mode of reactive magnetron sputtering.

The component of alloys target is atomic ratio Cu: Si: Sn=1: (0.1～2): (0.1～2), the interior pressure of sputtering chamber is 0.05Pa～10Pa during sputter, the distance of target and substrate is 3～15cm, the sputtering power of negative electrode target is 15～300W, underlayer temperature is 20～700 ℃, and rotates with 0～1000 rpm speed.

Each target can carry out direct current or radio frequency magnetron reactive sputtering.

Obtain Cu ₂Si _xSn _1-xS ₃The x value of photovoltaic film is 0～1.

Obtain Cu ₂Si _xSn _1-xS ₃The thickness of photovoltaic film is 0.2～5 μ m.

The present invention adopts reactive sputtering to satisfy well and obtains big area and high quality Cu ₂Si _xSn _1-xS ₃The requirement of photovoltaic film.By reactant gases is introduced in the sputter gas, react with quilt target atoms metal that sputter out, high energy, and on substrate, form the target compound film.This method and one thermal activation process have the difference of essence, it not only can realize one step of the low temperature deposition preparation of film, and since by the high energy target atoms metal that sputtered out in the substrate operational process, just fully reacting chemical combination, so reactive sputtering can be regulated and control the thing phase composite and the microstructure of deposit film very easily with reactant gases.Preparation method of the present invention has realized Cu ₂Si _xSn _1-xS ₃The one step growth of photovoltaic film, and experimental results show that the film of this method preparation removed in pressing down of the acquisition of big area homogeneity of ingredients, two second phases, the aspects such as regulation and control of the raising of thing phase crystalline quality and photoelectric property have traditional technology based on thermal activation incomparable advantage.In addition, this method adopts single target reactive magnetron sputtering, has also that technology is simple, cost is lower, favorable reproducibility, is easy to characteristics such as large-scale promotion.

Embodiment

Below in conjunction with embodiment, the present invention is described in further detail, but these embodiment must not be interpreted as limiting the scope of the invention.

Embodiment 1

With atomic ratio Cu: Si: Sn=1: 0.2: 1.7 Cu-Si-Sn alloys target is the negative electrode target, adopts the mode of d.c. sputtering, and sputtering power is 160W; Mixed gas with hydrogen sulfide and argon gas is a sputter gas, and the volume fraction of hydrogen sulfide is 5% in the mixed gas; The distance of target and substrate is 8cm, and underlayer temperature is 350 ℃, and rotates with 100 rpms speed, carries out thin film deposition.Acquisition x=0.15, thickness are the Cu of 1.2 μ m ₂Si _xSn _1-xS ₃Photovoltaic film, its conduction type are the p type, and band gap width is 1.02eV.

Embodiment 2

With atomic ratio Cu: Si: Sn=1: 0.5: 0.5 Cu-Si-Sn alloys target is the negative electrode target, adopts the mode of d.c. sputtering, and sputtering power is 80W; Mixed gas with hydrogen sulfide and argon gas is a sputter gas, and the volume fraction of hydrogen sulfide is 80% in the mixed gas, and the distance of target and substrate is 11cm, and underlayer temperature is 500 ℃, and rotates with 4 rpms speed, carries out thin film deposition.Acquisition x=0.45, thickness are the Cu of 1 μ m ₂Si _xSn _1-xS ₃Photovoltaic film, performance perameters such as its photoelectricity are as follows:

Thickness (μ m)	Resistivity (Ω cm)	Hall coefficient (m ²/C)	Hall mobility (cm ²V ^-1s ^-1)	Carrier concentration (cm ^-3)	Conduction type	Photoabsorption coefficient (cm ^-1)	Energy gap (eV)
Thickness (μ m)	Resistivity (Ω cm)	Hall coefficient (m ²/C)	Hall mobility (cm ²V ^-1s ^-1)	Carrier concentration (cm ^-3)	Conduction type	Photoabsorption coefficient (cm ^-1)	Energy gap (eV)	??1	??2.899	??65.13	??22.47	??9.584×10 ¹⁶	??p	??8.74×10 ⁴	??1.48

Embodiment 3

With atomic ratio Cu: Si: Sn=1: 1.7: 0.3 Cu-Si-Sn alloys target is the negative electrode target, adopts the mode of radio-frequency sputtering, and sputtering power is 30W; With the hydrogen sulfide is sputter gas, and the volume fraction of hydrogen sulfide is 50% in the mixed gas, and the distance of target and substrate is 6cm, and underlayer temperature is 650 ℃, and rotates with 500 rpms speed, carries out thin film deposition.Obtaining x=0.85 thickness is the Cu of 2 μ m ₂Si _xSn _1-xS ₃Photovoltaic film, its conduction type are the p type, and band gap width is 2.28eV.

Embodiment 4

With atomic ratio Cu: Si: Sn=1: 1.2: 1.1 Cu-Si-Sn alloys target is the negative electrode target, adopts the mode of radio-frequency sputtering, and sputtering power is 200W; Mixed gas with hydrogen sulfide and argon gas is a sputter gas, and the volume fraction of hydrogen sulfide is 20% in the mixed gas, and the distance of target and substrate is 14cm, and underlayer temperature is 100 ℃, and rotates with 700 rpms speed, carries out thin film deposition.Acquisition x=0.65, thickness are the Cu of 1.2 μ m ₂Si _xSn _1-xS ₃Photovoltaic film, its conduction type are the p type, and band gap width is 1.75eV.

Claims

1. Cu ₂Si _xSn _1-xS ₃The preparation method of photovoltaic film is characterized in that with hydrogen sulfide and argon gas mixed gas as the negative electrode target, carrying out depositing of thin film in the mode of reactive magnetron sputtering with the Cu-Si-Sn alloys target as sputter gas.

2. a kind of Cu according to claim 1 ₂Si _xSn _1-xS ₃The preparation method of photovoltaic film, it is characterized in that: the component of alloys target is atomic ratio Cu: Si: Sn=1: (0.1～2): (0.1～2), the interior pressure of sputtering chamber is 0.05Pa～10Pa during sputter, the distance of target and substrate is 3～15cm, the sputtering power of negative electrode target is 15～300W, underlayer temperature is 20～700 ℃, and rotates with 0～1000 rpm speed.

3. a kind of Cu according to claim 1 and 2 ₂Si _xSn _1-xS ₃The preparation method of photovoltaic film is characterized in that: the negative electrode target can carry out direct current or radio frequency magnetron reactive sputtering.

4. a kind of Cu according to claim 1 and 2 ₂Si _xSn _1-xS ₃The preparation method of photovoltaic film is characterized in that: the x of the film of this method preparation is 0～1.

5. a kind of Cu according to claim 1 and 2 ₂Si _xSn _1-xS ₃The preparation method of photovoltaic film is characterized in that: the thickness of the film of this method preparation is 0.2～5 μ m.