Perovskite precursor for deposition

Abstract

The present disclosure provides a perovskite precursor for deposition, an organic-inorganic halide perovskite deposition apparatus, and a perovskite thin film formed from the perovskite precursor for deposition. The perovskite precursor for deposition may comprise formamidinium iodide (FAI) and an organic halide compound.

Description

Perovskite precursors for deposition

[0001] The present disclosure relates to a perovskite precursor for deposition.

[0002] When organic and inorganic halide perovskites are dry-deposited, the organic halides (methylammonium iodide, formamidinium iodide) are prone to decomposition in vacuum. Decomposition of these organic halides can lead to significant difficulties in controlling the perovskite deposition process, including changes in the properties of the perovskite thin film, increased vacuum levels in the deposition device vacuum chamber, sensor cross-reading, and vacuum chamber contamination.

[0003] Formamidinium lead triiodide (FAPbI3) is often used as a perovskite layer in single-junction metal halide perovskite solar cells. However, methylenediammonium dichloride (MDACl2) has been used as an additive to ensure both phase stability and high photoelectric conversion efficiency of FAPbI3. According to one study, MDA 2+ is Cl - It is reported that MDA is incorporated into the perovskite lattice. In one study, single crystals were formed in a solution (FAPbI3-M) with added MDACl2, and it was found that these crystals were stable for more than a year under ambient conditions without transforming to the photoinactive δ phase. In the above study, MDA 2+ revealed that it is not the direct cause of the improvement in material stability, but instead MDA 2+ It was found that FAPbI3 rapidly decomposes to produce ammonium and methaniminium, which oligomerize to produce hexamethylenetetramine (HMTA). FAPbI3 crystals grown from a solution containing HMTA (FAPbI3-H) have the enhanced α-phase stability of FAPbI3-M.

[0004] As described above, numerous studies have investigated the improvement of stability by adding MDACl2 to organic halides in solution processes. However, in a process where perovskite precursors, organic halides (e.g., FAI) and inorganic halides (e.g., PbI2), are supplied from separate sources and deposited onto a single thin film, research on whether adding MDACl2 to the organic halides suppresses their decomposition remains insufficient.

[0005] The present disclosure aims to provide a perovskite precursor for deposition to solve the above-described problems. Furthermore, the present disclosure aims to provide a deposition device utilizing the perovskite precursor for deposition and a solar cell including a perovskite layer formed from the perovskite precursor.

[0006] A perovskite precursor for deposition according to one embodiment of the present disclosure may include formamidinium iodide (FAI) and an organic halide compound.

[0007] According to one embodiment of the present disclosure, the organic halide compound corresponds to methylenediamine dihydrochloride (MDACl2), and MDACl2 may be greater than 0% and less than or equal to 5% of the total weight of FAI.

[0008] According to one embodiment of the present disclosure, MDACl2 may be about 2.5% of the total weight of FAI.

[0009] According to one embodiment of the present disclosure, a deposition apparatus includes a substrate for halide perovskite deposition, a vacuum chamber on which the substrate is placed, and a supply source for supplying a halide precursor to the vacuum chamber, wherein the halide precursor may include FAI and MDACl2.

[0010] According to one embodiment of the present disclosure, MDACl2 may be greater than 0% and less than or equal to 5% of the total weight of FAI.

[0011] According to one embodiment of the present disclosure, MDACl2 may be about 2.5% of the total weight of FAI.

[0012] According to one embodiment of the present disclosure, a perovskite thin film formed from a perovskite precursor according to one embodiment of the present disclosure can be provided.

[0013] By using various embodiments of the present disclosure, the deposition process can be easily controlled, and a deposition perovskite solar cell can be manufactured through this process.

[0014] The effects of the present disclosure are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by a person having ordinary skill in the art to which the present disclosure belongs (referred to as “one skilled in the art”) from the description of the claims.

[0015] Embodiments of the present disclosure will be described below with reference to the accompanying drawings, wherein like reference numerals represent similar elements, but are not limited thereto.

[0016] Figure 1 is a graph showing the results of evaluating the deposition behavior of the existing commercial FAI of the present disclosure.

[0017] Figure 2 is a graph showing the results of evaluating the deposition behavior of FAI with about 2.5 wt% of MDACl2 added.

[0018] Figure 3 is a schematic diagram illustrating an organic-inorganic halide perovskite thin film deposition device.

[0019] Hereinafter, specific details for implementing the present disclosure will be described in detail with reference to the attached drawings. However, in the following description, specific descriptions of widely known functions or configurations will be omitted if they may unnecessarily obscure the gist of the present disclosure.

[0020] In the attached drawings, identical or corresponding components are assigned the same reference numerals. Furthermore, in the description of the embodiments below, duplicate descriptions of identical or corresponding components may be omitted. However, even if a description of a component is omitted, it is not intended that such component is not included in any embodiment.

[0021] The advantages and features of the disclosed embodiments, and methods for achieving them, will become clearer with reference to the embodiments described below, along with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below and may be implemented in various different forms. These embodiments are provided solely to ensure the completeness of the disclosure and to fully inform those skilled in the art of the scope of the invention.

[0022] The terms used in this specification will be briefly explained, followed by a detailed description of the disclosed embodiments. The terms used in this specification have been selected from widely used, current terms, taking into account the functions of the present disclosure. However, these terms may vary depending on the intentions of engineers working in the relevant field, precedents, the emergence of new technologies, etc. Furthermore, in certain cases, terms may be arbitrarily selected by the applicant, and in such cases, their meanings will be described in detail in the relevant description of the invention. Therefore, the terms used in this disclosure should not be defined simply as names of terms, but rather based on their meanings and the overall content of the present disclosure.

[0023] In this specification, singular expressions include plural expressions unless the context clearly indicates otherwise. Furthermore, plural expressions include singular expressions unless the context clearly indicates otherwise. When a part of the specification is said to include a component, this does not exclude other components, but rather implies that other components may be included, unless otherwise specifically stated.

[0024] Throughout this specification, whenever a part is said to "include" a component, this does not mean that it excludes other components, but rather that it may include other components, unless otherwise specifically stated.

[0025] The term "about" used throughout this specification is used to encompass the tolerance when there is a tolerance.

[0026] Throughout this specification, references to “A and / or B” mean “A or B, or A and B.”

[0027] Throughout this specification, “perovskite” or “PE” means a material having a perovskite crystal structure, which may have various perovskite crystal structures in addition to the ABX3 crystal structure.

[0028] Throughout this specification, a “device” may correspond to a device having a photoelectric conversion function or an electro-optical conversion function, for example, a solar cell.

[0029] Throughout this specification, the term "halide", "halogen", "halide" or "halo" means a material or composition containing a halogen atom belonging to Group 17 of the Periodic Table in the form of a functional group, which may include, for example, chlorine, bromine, fluorine or iodine compounds.

[0030] Throughout this specification, "precursor" may mean a precursor or reactant used to prepare a perovskite, and is not limited to a specific material.

[0031] Throughout this specification, “halide precursor” includes organic halide precursors and metal halide precursors.

[0032] Throughout the present specification, the organic halide may correspond to the chemical formula AX, where A is an organic cation and X may include, but is not limited to, a halide anion. For example, the organic halide may include, but is not limited to, Formamidinium Iodide (FAI).

[0033] Throughout this specification, the term "organic cation" refers to a cation containing carbon. The organic cation may additionally contain other elements, for example, hydrogen, nitrogen, or oxygen.

[0034] For example, the organic cation included in the organic halide may include at least one of methylammonium (MA), formamidinium (FA), or a combination thereof. For example, the organic halide may correspond to at least one of methylammonium chloride, methylammonium bromide, methylammonium iodide, formamidinium chloride, formamidinium bromide, or formamidinium iodide.

[0035] For example, organic cations have the chemical formula (R1R2R3R4N) + may have. In this case, R1~R4 are hydrogen, unsubstituted or substituted C1-C 20 It may correspond to alkyl, or unsubstituted or substituted aryl.

[0036] For example, an organic cation has the chemical formula (R5NH3) +, wherein R5 is hydrogen, or substituted or unsubstituted C1-C 20 It may correspond to alkyl.

[0037] For example, an organic cation has the chemical formula (R6R7N=CH-NR8R9) + , and in this case, R6~R9 can correspond to hydrogen, methyl, or ethyl.

[0038] Throughout the present specification, the metal halide may correspond to the chemical formula BX2, where B comprises a metal cation selected from the group consisting of Pb, Sn, Cu, Ni, Co, Fe, Mn, Cr, Pd, Cd, Yb, Ge, Ca, Sr, Eu and combinations thereof, and X may comprise a halide anion, but is not limited thereto. For example, the metal halide may correspond to, but is not limited to, PbI2.

[0039] Throughout the present specification, the perovskite compound may contain a monovalent organic cation, a divalent metal cation, and a halogen anion. In one embodiment, the perovskite compound of the present invention may satisfy the following chemical formula.

[0040] [Chemical Formula 1]

[0041] ABX3

[0042] In chemical formula 1, A is a monovalent cation, which may correspond to an organic ammonium ion, an amidinium group ion, or a combination of an organic ammonium ion and an amidinium group ion.

[0043] For example, an organic cation as A has the chemical formula (R1R2R3R4N) + may have. In this case, R1~R4 are hydrogen, unsubstituted or substituted C1-C 20 It may correspond to alkyl, or unsubstituted or substituted aryl.

[0044] For example, an organic cation as A has the chemical formula (R5NH3) + , wherein R5 is hydrogen, or substituted or unsubstituted C1-C 20 It may correspond to alkyl.

[0045] For example, an organic cation as A has the chemical formula (R6R7N=CH-NR8R9) + , and in this case, R6~R9 can correspond to hydrogen, methyl, or ethyl.

[0046] B can be a divalent metal ion. For example, B can be Cu 2+ , Ni 2+ , Co 2+ , Fe 2+ , Mn 2+ , Cr 2+ , Pd 2+ , Cd 2+ , Ge 2+ , Sn 2+ , Pb 2+ , Yb 2+ , and combinations thereof.

[0047] X may correspond to a halogen ion. For example, the halogen ion is I - , Br - , F - , Cl - and combinations thereof. Including, but not limited to, a halogen ion selected from the group consisting of:

[0048] For example, the perovskite compound may be one or a mixture of two or more selected from CH3NH3PbI3 (methylammonium lead iodide, MAPbI3) and CH(NH2)2PbI3 (formamidinium lead iodide, FAPbI3).

[0049] According to one embodiment of the present disclosure, the perovskite precursor is a precursor of the perovskite compound described above, and may correspond to an organic cation, a metal cation, or a halogen anion (X). The organic cation, metal ion, and halogen anion contained in the precursor may be the same as the monovalent organic cation (A), divalent metal ion (B), and halogen anion (X) described above in the perovskite compound.

[0050] Throughout this specification, the term "layer" refers to a layer having a thickness. The layer may be porous or non-porous. Porosity refers to having a void ratio. The layer may have a bulk form as a whole or may correspond to a single crystal thin film, but is not limited thereto.

[0051] Perovskite layers can be formed through various processes, including vapor deposition processes or solution processes. According to one embodiment of the present disclosure, the perovskite layer can be formed using a vapor deposition process. The vapor deposition process may correspond to a process in which a substance is supplied into a vacuum chamber in a vaporized or plasma state, thereby depositing the substance on the surface of a target object (e.g., a substrate).

[0052] An organic / inorganic halide perovskite deposition device according to one embodiment of the present disclosure may include a substrate for halide perovskite deposition, a vacuum chamber in which the substrate is mounted, and a supply source for supplying a halide precursor to the vacuum chamber. Here, the halide precursor may include FAI and MDACl2.

[0053] The supply source of the above-described deposition device can supply at least one precursor used in manufacturing a perovskite thin film to a vacuum chamber. The supply source can be divided into a supply source for supplying an organic halide precursor and a supply source for supplying a metal halide precursor. Without being limited thereto, the device according to the present disclosure can include a number of supply sources corresponding to the number of precursors used in the deposition of an organic-inorganic halide perovskite thin film.

[0054] FAI decomposes through the following pathway when heated in vacuum: deprotonation of FAI salt occurs, followed by an equilibrium reaction of formamidine to hydrogen cyanide and hydrogen iodide, followed by a reaction of formamidine to 1,3,5-sym-triazine and ammonia.

[0055] To suppress the deprotonation reaction of the FAI salt, which is the first reaction of the above decomposition pathway, a small amount of MDACl2 additive, a type of organohalide compound, was added to FAI, and the deposition behavior was evaluated using FAI as a perovskite precursor for perovskite solar cells. In the present disclosure, organohalide compounds are used as additives in perovskite precursors for deposition, and exemplary organohalide compounds include MDACl2.

[0056] In order to quantify and compare the behavior of deposition, a standardized method was established to simultaneously monitor the deposition rate from an arm sensor located near the substrate and a source sensor located directly above the source where the material is deposited, and to plot and compare the vacuum level of the vacuum chamber and the temperature of the source.

[0057] Fig. 1 is a graph showing the results of an evaluation of the deposition behavior of a conventional commercial FAI of the present disclosure. Fig. 2 is a graph showing the results of an evaluation of the deposition behavior of FAI with approximately 2.5 wt% of MDACl2 added.

[0058] In Figures 1 and 2, the x-axis represents deposition time, the y-axis represents temp. and Temp. lines represent the temperature of the source, the rate (#1) and #3 Rate lines represent the deposition rate at the source sensor, the rate (#4) and #4 Rate lines represent the deposition rate at the sensor (arm-sensor) near the substrate, and the pressure and Pressure lines represent the working pressure within the vacuum chamber.

[0059] It can be confirmed that the deposition rates based on the source sensors of the rate (#1) and #3 Rate lines and the sensors near the substrate of the rate (#4) and #4 Rate lines in FIGS. 1 and 2 are the same. In other words, the deposition rates of the FAI are controlled identically.

[0060] Unlike Fig. 1, it can be seen that the operating pressure of the Pressure line in Fig. 2 has significantly decreased. The lack of an increase in the operating pressure means that the degree of vacuum has not increased, and the lack of an increase in the degree of vacuum means that decomposition of FAI has not occurred.

[0061] Therefore, it can be confirmed that the FAI synthesized by adding about 2.5% of MDACl2 according to one embodiment of the present disclosure does not decompose during deposition compared to the existing FAI.

[0062] According to one embodiment of the present disclosure, the amount of the additive MDACl2 that can exhibit the effect of suppressing decomposition during deposition as described above may be greater than 0% and less than or equal to 5% of the total weight of the FAI. Therefore, the FAI to which MDACl2 is added in an amount greater than 0% and less than or equal to 5% of the total weight of the FAI can be said to be a perovskite precursor material suitable for the deposition process.

[0063] A perovskite solar cell including a perovskite thin film formed by depositing a perovskite precursor as described above on a thin film exhibits high photoelectric conversion efficiency (PCE) and, at the same time, is easy to control the deposition process, such as minimizing changes in the characteristics of the perovskite thin film.

[0064] The present invention provides a perovskite precursor suitable for a deposition process, and a deposition device utilizing the same and a solar cell including a perovskite thin film formed with the perovskite precursor can be provided.

[0065] In the present disclosure, the tooling factor may refer to the ratio between the thickness of the perovskite thin film actually deposited on the substrate and the thickness of the thin film deposited on the measurement sensor. That is, the tooling factor may be expressed as follows.

[0066] Tooling factor (%) = thickness of film deposited on substrate / thickness of film deposited on sensor

[0067] FIG. 3 is a schematic diagram illustrating an organic / inorganic halide perovskite thin film deposition device. As illustrated, the deposition device may include a substrate (110) for organic / inorganic halide perovskite deposition, a vacuum chamber (120) in which the substrate is placed, a supply source (130) for supplying a halide precursor to the vacuum chamber (120), a first sensor (140) for measuring a first deposition rate at which the halide precursor is deposited at a location other than the substrate, and a second sensor (150) for measuring a second deposition rate at which the halide precursor is deposited on the substrate. Additionally, the device may include a control unit (not shown in the drawing) for controlling the rate at which the halide precursor is supplied to the vacuum chamber.

[0068] A supply source (130) can supply at least one precursor used in manufacturing a perovskite thin film to a vacuum chamber. The supply sources can be divided into supply sources (132, 134) for supplying organic halide precursors and supply source (136) for supplying metal halide precursors, as illustrated in FIG. 3 . Without being limited thereto, the device according to the present disclosure can include a number of supply sources corresponding to the number of precursors used in the deposition of organic and inorganic halide perovskite thin films.

[0069] The first sensor (140) can measure the first deposition rate at which the halide precursor is deposited at a location other than the substrate.

[0070] For example, a first sensor may be installed around the supply source (130) to measure the deposition rate of the halide precursor when it is deposited near the supply source. This deposition rate may be used to measure the amount of precursor actually emitted from the supply source.

[0071] The first sensor (140) may include a first sensor (142, 144) for measuring a first deposition rate at which the organic halide precursor is deposited at a location other than the substrate, and a first sensor (146) for measuring a first deposition rate at which the metal halide precursor is deposited at a location other than the substrate. Without being limited thereto, the device according to the present disclosure may include a number of sensors corresponding to the number of supply sources. In this case, the location other than the substrate may correspond to a side, top, or side top of a supply source supplying each precursor.

[0072] The reason why the first deposition rate measurement, in which the halide precursor is deposited at a location other than the substrate, is necessary is because the deposition rate of the halide precursor is significantly affected by the deposition environment, particularly the deposition location. The adsorption characteristics of the halide precursor can vary. For example, the deposition rate of the halide precursor can significantly vary depending on the relative positions of the source and the substrate. Therefore, the first deposition rate measurement may be necessary for depositing high-quality perovskite thin films.

[0073] Furthermore, when multiple halide precursors are deposited together, the first deposition rate measurement is essential because the deposition of each precursor affects the deposition rate of the others. For example, the deposition rate of the organic halide when only the organic halide is deposited may differ from the deposition rate of the organic halide when the organic halide and metal halide are deposited together.

[0074] The second sensor (150) can measure the second deposition rate at which the halide precursor is deposited on the substrate. The second sensor may be located on the periphery or side of the substrate, but is not limited thereto, and may be installed directly on the substrate. In other words, the second sensor and the substrate may be configured in a form that is coupled to each other so that the amount of precursor reaching the substrate matches the amount of precursor reaching the second sensor.

[0075] In one embodiment, the first sensor or the second sensor may be configured to measure the thickness of a material deposited on the sensor. For example, the first sensor or the second sensor may be configured to measure the thickness of a material deposited on the sensor. Deposition thickness of the unit and It can provide information to monitor the deposition rate in units of / s.

[0076] In another embodiment, the first sensor or the second sensor may be configured to measure a change in mass of a material deposited on the sensor. Specifically, the first sensor or the second sensor may measure a change in mass of the material based on the resonant frequency of the quartz constituting the sensor. The change in resonant frequency of the quartz and the change in mass of the deposited material may have a relationship as shown in Mathematical Expression 1 below.

[0077]

[0078]

[0079] Here, the c value is 0.081 Hz·ng based on 6 Mhz quartz. -1 ·cm -2 Therefore, the mass change can be calculated based on the frequency change.

[0080] The control unit may be configured to control each component of the device and determine an effective deposition rate at which the halide precursor is deposited on the substrate. For example, the control unit may determine an effective deposition rate at which the halide precursor is deposited on the substrate based on the first deposition rate and the second deposition rate.

[0081] Specifically, the control unit can determine an effective deposition rate at which the organic halide precursor is deposited on the substrate by subtracting the first_2 deposition rate from the second deposition rate in the process of increasing the first_2 deposition rate while maintaining the first_1 deposition rate constant.

[0082] The control unit, as a preliminary step prior to determining an effective deposition rate of the organic halide precursor, supplies a metal halide precursor to a vacuum chamber, and corrects a tooling factor based on the rate at which the metal halide precursor is deposited on the first and second sensors and the rate at which the metal halide precursor is deposited on the second sensor, thereby determining a deposition rate range in which the rate at which the metal halide precursor is deposited on the first and second sensors matches the rate at which the metal halide precursor is deposited on the second sensor.

[0083] Then, the control unit can stabilize the first sensor and the second sensor by keeping the deposition rate of the organic halide precursor constant in the effective deposition rate measurement step after the pre-step. Thereafter, the control unit can increase the deposition rate of the metal halide precursor (the first_second deposition rate) within the deposition rate range determined above. While the control unit increases the deposition rate of the metal halide precursor (the first_second deposition rate), the effective deposition rate at which the organic halide precursor is deposited on the substrate can be determined based on the rate at which the precursor is deposited on the second sensor (the second deposition rate) and the deposition rate of the metal halide precursor (the first_second deposition rate).

[0084] The control unit can calculate the molar composition of the organic halide and metal halide deposited on the substrate based on the effective deposition rate. The control unit can control the deposition rate of the precursor or the supply rate of the precursor from the source based on the composition ratio. Through this configuration, the composition of the perovskite thin film can be precisely monitored and controlled during the vacuum deposition process.

[0085] The previous description of the present disclosure is provided to enable any person skilled in the art to make or use the present disclosure. Various modifications to the present disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to various modifications without departing from the spirit or scope of the present disclosure. Thus, the present disclosure is not intended to be limited to the examples described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0086] While the present disclosure has been described in connection with certain embodiments herein, various modifications and variations may be made without departing from the scope of the present disclosure, which would be apparent to those skilled in the art. Furthermore, such modifications and variations are intended to fall within the scope of the claims appended to this specification.

[0087] The above preferred embodiments of the present invention are disclosed for the purpose of illustration, and those skilled in the art with ordinary knowledge of the present invention will be able to make various modifications, changes, and additions within the spirit and scope of the present invention, and such modifications, changes, and additions should be considered to fall within the scope of the patent claims.

[0088] Anyone having ordinary skill in the art to which the present invention pertains can make various substitutions, modifications, and changes within the scope that does not depart from the technical spirit of the present invention, and therefore the present invention is not limited to the above-described embodiments and the attached drawings.

Claims

1. As a perovskite precursor for deposition, formamidinium iodide (FAI); and organic halide compounds A perovskite precursor comprising:

2. In paragraph 1, The above organic halide compound corresponds to methylenediamine dihydrochloride (MDACl2), The above MDACl2 is a perovskite precursor, which is greater than 0% and less than or equal to 5% of the total weight of FAI.

3. In paragraph 2, The above MDACl2 is a perovskite precursor, which accounts for 2.5% of the total weight of FAI.

4. As an organic-inorganic halide perovskite deposition device, Substrate for deposition of organic and inorganic halide perovskites; a vacuum chamber in which the substrate is placed; and A source for supplying a halide precursor to the vacuum chamber Including, The above halide precursor comprises FAI and MDACl2. Deposition device.

5. In paragraph 4, A deposition device wherein the above MDACl2 is greater than 0% and less than or equal to 5% of the total weight of FAI.

6. In paragraph 5, The above MDACl2 is 2.5% of the total weight of FAI, deposition device.

7. A perovskite thin film formed from a perovskite precursor according to any one of claims 1 to 3.

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