TWI377684B - Si-ge thin-film solar cells with poly-germanium thin film and method for performing the same - Google Patents

Description

1377684 IX. Description of the invention: [Technical field to which the invention pertains] The present invention is a thin film type solar cell, and more particularly to a solar cell having a tantalum film of a polycrystalline germanium film. [Prior Art] Due to the rising cost of energy and the increasing shortage of global oil prices and resources, 'the world's major advanced countries have actively invested in research and development of renewable energy to replace the dependence on natural resources such as oil. In addition, the problem of global greenhouse effect has become more and more serious in recent years. Due to the large amount of greenhouse gas emissions (eg, carbon monoxide) emitted by human beings, the environment and climate in the world have become quite abnormal. In order to avoid the deterioration of this phenomenon, green energy has already In view of this, it is urgent to develop new alternative energy sources. ... Alternative energy sources mainly include solar energy, @力,水力, geothermal, and biological, etc., and its solar energy is inexhaustible. Solar cells have taken a pivotal role in power, communications, electronics and transportation, especially in space and in remote areas. In terms of materials, solar cells can be roughly divided into three categories: crystalline germanium, compound semiconductors and organic materials. Compound semiconductors are mostly compounds of the three-five and six-group compounds. Although the efficiency is high, they are expensive, and they are used in Minsheng City. Not easy to use and 'applicable to space development applications. Organic materials solar cell efficiency jobs are currently not commoditized. The development of crystal germanium solar cells 6 1377684 is the mainstream of the market, but its efficiency is slightly lower than that of compound semiconductor solar cells, but the price is more acceptable to the market. However, the current situation of shortage of raw materials in Shixi is serious and cannot be solved in the short term. Only the solar cells used in the original science of saving Shi Xi #粗# aei ηβ & $ 7 are used, and even other materials are used instead, so the guest eroded the wall. The solar cell solar cell can solve this problem, and it can be used to improve the absorption of long-wavelength light with the original thin amine gentleman ^, ,, 'Ό s, and its thickness is about 2 U m , Advise μ , μ is much smaller than the 300~350μm of the general block type solar cell.

Generally, thin film solar cells can be fabricated by using PE_CVD, hw cvd, cat CVD, VHF-CVD, etc., all of which require expensive gas.

SiH4 ΒΖΗ6 and phs and other gases, and also have toxicity and explosion hazard. SUMMARY OF THE INVENTION In the present invention, a polycrystalline film is prepared by a metal-induced crystallization method, and in addition to φ: a gas which is expensive and high-risk is required, it has the advantages of simple low temperature and large area. In view of the foregoing technical problems and the object of the invention, the present invention provides a method for fabricating a tantalum thin film solar cell having a polycrystalline germanium film, the step of which includes: an eight-ply substrate preparation, a substrate is selected, and formed on the substrate a first electrode layer; a deposition-inducing metal film attached to the surface of the first electrode layer and formed by an physical vapor deposition process to form an induced metal layer; 7 1377684 depositing a germanium film on the surface of the induced metal layer to physically Forming a germanium-type semiconductor germanium film by a vapor deposition process; inducing crystallization, sequentially forming a surface of the first electrode layer, the inducing metal layer, and the germanium-type semiconductor germanium film by heat treatment to make the germanium semiconductor germanium Forming a P-type ruthenium layer; removing the induced metal, removing the induced metal layer formed on the ruthenium-type ruthenium layer by etching; depositing a type I ruthenium film on the surface of the P-type ruthenium layer, and adopting a physical gas phase a deposition process for plating a tantalum-type tantalum film; depositing an N-type tantalum film on the surface of the tantalum-type tantalum film, and plating an N-type tantalum film by a physical vapor deposition process; A second electrode, based on the N-type silicon film surface, forming a second electrode layer. The substrate preparation step selects a glass substrate and forms a transparent conductive first electrode layer on the surface of the glass substrate, wherein the transparent conductive first electrode layer is recorded by a physical vapor deposition process. Wherein, the deposition inducing metal film is a physical vapor deposition of an aluminum metal layer. Wherein, the step of depositing the ruthenium-type ruthenium film is to form an amorphous bismuth-type semiconductor ruthenium film by physical vapor deposition. Wherein, the inducing crystallization step is to heat-anneal the substrate on which the 丨-type semiconductor erroneous film is completed by a high-temperature furnace tube, so that the 丨-type semiconductor ruthenium film is induced to be crystallized by the induced gold, and the metal layer is induced. The germanium-type semiconductor germanium is replaced with each other to form the p-type germanium layer.

S 1377684 wherein the thickness of the induced metal layer is 300 to 7 〇〇 nm, the f-type. The semiconductor germanium has a thickness of 500 nm, and the temperature of the induced crystallization step is greater than °C' processing time by more than 2 hours. The thickness of the ruthenium-type ruthenium film is larger than that of the P-type ruthenium layer and the N-type ruthenium film. The invention further provides a solar photovoltaic solar cell having a polycrystalline film comprising: a substrate;

a first electrode layer is formed on the substrate; a P-type germanium layer is formed by inducing crystallization to form a polycrystalline P-type germanium layer formed on the first electrode layer; and a germanium-type germanium film is formed thereon The N-type smectic film on the surface of the p-type enamel layer is formed on the surface of the ruthenium-type ruthenium film-metal electrode layer, and is formed on the N-type ruthenium film. And wherein the substrate is a conductive oxide. Glass substrate' the first electrode layer is __transparent

Wherein the first electrode layer is 丨τ〇, |z〇 'AZ〇 or Zn〇. / In the middle, the thickness of the ruthenium-type ruthenium film is larger than the p-type 锗 锗 potential and the N-type 夕 薄膜 film. Therefore, the present invention can complete the fabrication of various semiconductor layers of the present invention by using a relatively simple, low-overflow and safe physical vapor deposition process, and complete the P-type germanium layer by metal induced crystallization to simplify the process and reduce the process. Temperature and many other advantages. 9 137/084 . [Embodiment] · 第 第 以及 第二 第二 第二 第二 第 第 第 第 第 第 第 第 第 第 第 第 第 第 第 第 第 第 第 第 第 多 多 多 多 多 较佳 较佳 较佳The method for fabricating the germanium thin film solar cell is as shown in the first figure, and the steps include: substrate preparation (71), deposition-induced metal thinning (72), deposition of germanium film (73), induction Crystallization (74), removal of induced metal (5) / enthalpy type; 5 eve film (76), deposition of N-type slab film a?) and formation of the _ electrode (78). In the step of preparing the substrate (71), a substrate (12) having a high temperature resistance (about > 5 Å < ^) is selected. The substrate (12) may be a light transmissive (such as a surface) or a non-transparent substrate. (such as metal substrates, flexible metal sheets, etc.). After the substrate (12) is selected, a first electrode layer (14) is formed on one side of the substrate (12), and the first electrode layer (14) can be formed on the substrate by physical vapor deposition ((7) surface The substrate (12) of the preferred embodiment is a glass substrate (e.g., c〇rnjng E2000). The first electrode layer (14) is a transparent conductive film (such as indium tin oxide) formed on the surface of the substrate (12). (丨τ〇) 'indium zinc oxide (丨z〇)' aluminum zinc oxide (AZ0) or zinc oxide (Zn), etc.) • In order to ensure the film quality of the 6 Xuan substrate (12), in the thickness Before the bond film, the cleaning process can be performed first. For example, the substrate (12) can be shaken with acetone for 10 knives to remove the organic matter on the substrate (12), and then washed with ethanol for ten minutes to remove the acetone. Residue, and finally use deionized water to wash the ten-knife clock to remove the ethanol residue, then use nitrogen to blow dry, and finally use the oven to bake the substrate (12) for 1-2 minutes to remove the water molecules on the substrate (12). Thoroughly supplied. 1377684 The deposition inducing metal film (72) is in the first electrode (14) The surface is formed by a physical vapor deposition method (for example, egun, thermal resistance wire steaming, etc.) to form a metal layer, and the material of the metal layer may be a eutectic reaction with Amorpha In the preferred embodiment, the heat-resistant silk evaporation device is used to form the surface of the first electrode layer (14). The process and parameters of the process are as follows: 5M0-2 t0 "", then finely pumped to 8 6χ1〇.6 In the steaming process:: It should be noted that the deposition rate should not be too fast (for example, less than 5 A/sec) to avoid the compactness of the film. And manufacturing the process towel, the substrate (12) can be continuously rotated, and (4) the surface of the first-f-pole layer (14) of the thin film substrate (12). After completing the previous step (72), the substrate (12) is formed on the surface of the induced metal layer by a physical vapor deposition method to form a non-B-type I-type semiconductor germanium film on the induced metal specific surface. In fact, the dry material of the 丨-type semiconductor 形成 is formed by means of SPutter - a type I semiconductor erroneous film in the induced gold The surface of the layer, the process parameters of this step are as follows: first rough pumping to 5 χΐ〇 · 3 (〇 "", then change fine! ^ 5x10.6torr, you can start the faulty film, the process environment is in the wind' ( A 〇 = 4Gsc: cm of electric i gas, Wang Zuo pressure is 1Q (7) ding, bismuth ore power & thoroughly W, and finally deposited 锗 type I semiconductor wrong film thickness is 50 〇 nm. Induced crystallization (74) step , in a heat treatment manner, the substrate (12) of the completion of the moon is heated and annealed at a specific temperature, for example,

The base material (12) which has been plated with the 锗W conductor 锗 and the induced metal layer is heated by using a south temperature furnace tube, a replacement technique, a P type abundance, an annealing chamber, etc., so that the 137 type 1378684 semiconductor is wrong. The crystallization is induced by the induced metal layer, and the induction is caused by the partial embroidered metal layer remaining in the formation of the polycrystalline t-type semiconductor layer, which is equivalent to doping to form the _P(10) layer. (22) attached to the surfaces of the two first electrode layers (14). Among them, the properties of the P-type tantalum layer (22) are related to the thickness ratio of the induced metal layer, the tantalum & semiconductor layer, the heat treatment temperature, and the like. For example, as shown in the fourth (aHd) diagram, the induced metal layer and the germanium-type semiconductor germanium layer having different thickness relationships are subjected to a fixed annealing temperature of 45 (rc, SEM observation after 6 hours of treatment, induced metal layer and germanium). The thickness of the semiconductor layer is as follows: (a): Al = 300 nm, Ge = 500 nm (3: 5); (b): Al = 400 nm, Ge = 500 nm (4: 5); (c): Al = 500 nm , Ge = 500nm (1 : ”; (d): Al = 700nm, Ge = 500nm (7 : 5) ° where, at an annealing temperature of 45 (TC, annealing time of 6 hours has produced different displacement effects, such as the fourth ( c) The parameters corresponding to the figure have the best replacement effect in the process environment. The following Tables 1 to 8 are various materials analysis tests for different heat treatment temperature and time, different induced metal layer and semiconductor germanium layer thickness. Results: Table 1 EDS analysis results of different Al/Ge thicknesses at (450 ° C, 6 hrs) heat treatment conditions (Al / Ge thickness) (300 / 500) Am (400/500) nm (500/500) nm (700 /500) nm Element Element Atomic% Atomic% Atomic% Atomic% 12 1377684 Aluminum Al K 73.85 71.36 82.14 80.74 锗GeL 26.15 28.64 17.86 19.26 Table 2 EDS analysis results of different Al/Ge thicknesses at (450 °C ' 4hrs) heat treatment conditions (Al/Ge thickness) (100/500) nm (300/500) nm (400/500) nm ( 500/ 500) nm (700/ 500) nm Element Element Atomic% Atomic% Atomic% Atomic% Atomic% Ming Al K 46.72 76.95 78.48 46.53 76.12 False Ge L 53.28 23.05 21.52 53.47 23.88. Table 3 Different Al/Ge Thickness at (550 °C, 4hrs) EDS analysis results of heat treatment Change conditions (Al / Ge thickness) (300/500) nm (400 / 500) nm (500 / 500) nm (700/500) nm Element Element Atomic% Atomic% Atomic% Atomic% Al Al 59 59.06 61.67 84.76 82.81 锗Ge L 40.94 38.33 15.24 17.19 Table 4 Al/Ge thickness (1:1), EDS analysis results at different heat treatment times at 550 °C (Al / Ge thickness) 2hrs 4hrs 6hrs 8hrs Element Element Atomic% Atomic% Atomic% Atomic% Aluminum Al K 59.45 84.76 66.77 64.11 False Ge L 40.55 15.24 33.23 te.89 Table 5 Crystallization of Ge/AI phases after heat treatment at different temperatures (relative intensity greater than 40 Ge) (111) Al(111) Ge(220) Ge(311) Ge(331) As-deposited ◎ 400°C ◎ ◎ 13 1377684

As shown in the above table, after EDS and XRD material measurement analysis, it can be summarized at annealing temperature 55CTC, annealing time 4 hours, thickness matching is AI (induced metal layer) = 500nm 'Ge (丨-type semiconductor germanium layer) = 5 The displacement effect obtained by 〇〇nm (1:1) is the most obvious, and the measurement result of XRD is as shown in the fifth figure. In the step of removing the induced metal (75), the induced metal layer is removed by dry or wet etching. The preferred embodiment uses the dish acid as the main etchant component because the phosphoric acid etched aluminum material has a good effect. At the same time, different ratios of acid and acetic acid to phosphoric acid are added, because the mechanism of the surname is to form alumina by reaction with nitric acid and then react with phosphoric acid to form a water-soluble acid-filling acid as a buffer. Its function mainly prevents the dissociation of tartaric acid in water and changes the buttoning rate. Among them, nitric acid only accounts for 1~3〇/〇 of the etching solution, but the work of oxidizing is carried out. Secondly, since the etching solution is sensitive to temperature, the temperature of aluminum etching heating is about 35~50°C, and the temperature is higher. The faster the rate is, the better the process temperature is selected, which is quite helpful for the stability of the surname and the stability of the hook. 14 1377684 - In the step of depositing the type I stone film (76), the ruthenium-type ruthenium film (24) is deposited by a physical vapor phase process to complete the surface of the test piece of the foregoing steps, = due to the step (75) The inducing metal layer has been removed, so the 4th type film (24) of this step is plated on the p-type germanium layer (called a surface. The preferred embodiment uses a de-plating machine to deposit a type I stone film) (24), and the process workers = conditions can be · · rough pumping 5 咐 6 丨. Xintong people argon for his coffee, the work of extinguishing the plating is 10 m Ding orr, the power is (10) w. Among them: 丨 type: film ( 24) The thickness is about _. Among them, the 丨(4) film (4) is slightly larger than the P-type layer (22) layer, which is based on the theory of semiconductor physics, in the P + n structure of the solar cell, due to! · For the migration Q domain of the (four) junction, there is a large built-in electric field, which can suppress the composite generation of the carrier, which can increase the photocurrent of the solar cell. Therefore, the I layer needs to be much thicker than the layer. Depositing a Ν type (4) 臈 (77) step towel, on the surface of the film (24), and then forming a Ν Ν thin 臈 (26), which can be physically vapor deposited In the preferred embodiment, the thickness of about 〇5 石 石 薄膜 film (26) is plated on the surface of the ruthenium-type ruthenium film (24) by a splashing clock. The step of forming the first electrode (78) And forming a second electrode layer (4) on the surface of the 6-inch-type broken film (26) by vapor deposition or coating or bonding, and the preferred embodiment is Silver paste is applied to the surface of the ruthenium-type ruthenium film (26). BRIEF DESCRIPTION OF THE DRAWINGS The first figure is a flow chart of a preferred embodiment of the present invention. 15 1377684 Layered junction of the example 4 The second figure is a better schematic diagram of the present invention. = Electron LX light diffraction after microscopy (SEM) processing. The second figure is a better observation result of the present invention. The fourth (a) to (d) figure is Fig. 5 is a diagram showing the results of microscopic observation of a preferred embodiment of the present invention. Fig. 5 is a diagram showing the results of heat treatment after a preferred embodiment of the present invention. [Description of main components] (1) substrate (14) first electrode layer (22) P-type tantalum layer (24) tantalum-type tantalum film (26) N-type tantalum film (32) second electrode layer

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Claims (1)

1377684 1 07 1 July replacement page X. Patent application scope: 1. A method for manufacturing a silicon thin film solar cell with a polycrystalline germanium film, the steps of which include '· substrate preparation, using a substrate and on the substrate Forming a first electrode layer; depositing a metal thin raft, attached to the surface of the first electrode layer, and forging an organic metal layer by a physical vapor deposition process; depositing a wrong film, which is attached to the phoenix And performing a two-dimensional layer of the food layer, and plating a silicon-type semiconductor germanium film by a physical vapor deposition process; inducing crystallization, performing the first electrode layer, the inducing metal layer, and the substrate of the germanium-type semiconductor wrong film The rail treatment, the value of the # 兮丨 # 值 值 值 值 值 + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + The induced metal layer is removed; and the I-rich film is deposited on the surface of the P-type ruthenium layer, and the ruthenium type is formed by a physical vapor deposition process; the 5 夕 film; the deposited N-type ruthenium film is attached to the 矽 type 矽Membrane surface 'Children's process to make an N-type stone film; forming a second electrode, forming a second electrode layer on the surface of the N-type stone film; wherein 'the thickness of the induced metal layer is 3〇〇~7〇〇 _, the semiconductor semiconductor has a thickness of 500 nm' and the temperature of the induced crystallization step is greater than C, and the treatment time is more than 2 hours. 2. The polycrystalline tantalum film of the first π scare according to the patent application scope The manufacturing method of the solar cell, the substrate, and the formation of the transparent conductive one, the transparent conductive first Christine, July 5, 2011 - the substrate preparation step is selected - the electrode layer on the surface of the glass substrate, the polar layer The physical vapor deposition process money 3. As described in the patented scope of the film solar cell production item, the polycrystalline silicon (4) is a stone-vapor-deposited metal layer. The deposition-induced metal film is a physical film 4 solar 7 Please refer to the polycrystalline tantalum film described in the first item of Patent 1 (9). The method of depositing the ruthenium-type ruthenium film is based on the physical 虱 phase deposition to form amorphous 丨 、, #^豕丨 type + conductor 锗 film. 5 For example, in the patent application, the polycrystalline enamel thin 臈 石 锗 锗 专 专 太 太 太 太 太 太 太 太 专 专 专 专 专 诱发 诱发 诱发 诱发 诱发 诱发 诱发 诱发 诱发 诱发 诱发 诱发 诱发 诱发 诱发The substrate of the 丨-type semiconductor crucible '4 film is heat-annealed, and the 兮-type semiconductor 锗 film is subjected to crystallization induced by the metal layer induced by the shovel, and the induced metal layer is induced. And the 丨-type semi-conductive 千 千 锗 锗 锗 锗 锗 锗 锗 锗 锗 锗 锗 锗 锗 锗 锗 锗 锗 锗 锗 锗 锗 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 A method for fabricating a tantalum film solar cell, the tantalum layer and the tantalum film. 7. A polycrystalline silicon solar cell having a polycrystalline germanium film, comprising: a substrate; a first electrode layer formed on the substrate; and an electrode layer formed on the electrode layer to induce The crystallization method is in the first polycrystalline one Ρ type 锗 layer; the 18 _ type film is formed on the p type VVT ～N type 矽 film, which is formed on the surface of the 矽 type 矽 film; — the metal electrode layer Formed on the surface of the N-type tantalum crucible; wherein the thickness of the tantalum-type tantalum film is greater than the thickness of the p-type tantalum. The main layer and the 泫NI type 'special film solar cell transparent conductive oxide / Β 网 碍 矽 , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , ... Ή 专 四 四 四 四 四 四 四 四 四 四 四 薄膜 薄膜 薄膜 薄膜 薄膜 薄膜 薄膜 薄膜 薄膜 薄膜 薄膜 薄膜 薄膜 薄膜 薄膜 薄膜 薄膜 薄膜 薄膜 薄膜 薄膜 薄膜 薄膜 薄膜 薄膜 薄膜 薄膜 薄膜 薄膜 薄膜 薄膜 薄膜 薄膜 薄膜 薄膜ΑΖ〇) or zinc oxide (Ζη〇) β milk eleven, schema: as the next page. 19