KR20140127687A - Molybdenum precursors with aminothiolate, preparation method thereof and process for the formation of thin films using the same - Google Patents

Abstract

The present invention relates to a molybdenum precursor represented by the following Chemical formula 1 or 2. The molybdenum precursor has an advantage of being thermally stable and having high volatility, and can form a high quality molybdenum sulfide thin film by using the same. [Chemical formula 1] (In the formula, R1 is a linear or branched alkyl group of C1-C4, R2 and R3 are each an independently linear or branched alkyl group of C1-C10, R4 and R5 are each an independently linear or branched alkyl group of C1-C10 or a linear or branched fluoroalkyl group of C1-C10, R6 is a linear or branched alkyl group of C1-C10, and n is selected from integers of one to three.) [Chemical formula 2] (In the formula, R1 is a linear or branched alkyl group of C1-C4, R2 and R3 are each an independently linear or branched alkyl group of C1-C10, R4 and R5 are each an independently linear or branched alkyl group of C1-C10 or a linear or branched fluoroalkyl group of C1-C10, n is selected from integers of one to three, and X is Cl, Br, or I.).

Description

TECHNICAL FIELD The present invention relates to a molybdenum precursor using aminothiourea, a method for producing the molybdenum precursor, and a method for forming a thin film using the same. BACKGROUND ART [0002] MOLYBDENUM PRECURSORS WITH AMINOTHIOLATE, PREPARATION METHOD THEREOF AND PROCESS FOR THE FORMATION OF THIN FILMS USING THE SAME,

The present invention relates to a novel molybdenum precursor, and more specifically, to a molybdenum precursor which is improved in thermal stability and volatility and can be easily produced at a low temperature and can be easily produced in a molybdenum sulfide thin film, a method for producing the same, and To a method for producing a molybdenum sulfide thin film.

The CIGS (Copper Indium Galium Selenide) or CZTS (Copper Zinc Tin Sulphide) thin film solar cell can be manufactured with a thin thickness compared with the conventional solar cell using silicon crystal, and has stable characteristics even when used for a long time. , It is known that a highly efficient thin film solar cell capable of replacing a silicon crystalline solar cell is highly commercialized.

In particular, in order to fabricate a solar cell with high efficiency used as a p-type light absorbing layer, the band gap energy should be in the range of 1.4-1.5 eV and the absorption coefficient should be 10 ⁴ cm ^-1 Or more. For this purpose, studies on the materials of solar cells through various methods such as co-evaporation, sputtering, and sol-gel method have been actively conducted at home and abroad.

Among these materials, tungsten (W) and molybdenum (Mo) are materials having a low resistance value and have excellent electrical conductivity and thermal stability, and are currently used actively as back electrode for CIGS (Copper Indium Galium Selenide) solar cell. For example, WS ₂ has a band gap energy of 1.32-1.4 eV in the thin film form and 1.8 eV in the bulk solid state. In addition, a single layer of MoS ₂ has a band gap energy of 1.8 eV.

In particular, Bin Yu, Professor of the United States of America, has proposed a _two- dimensional semiconductor material such as WS ₂ and MoS ₂ , which is a two-dimensional semiconductor material in Schottky barrier solar cell based on-layer semiconductor tungsten disulfide nanofilm. A solar cell using WS ₂ was disclosed. Specifically, Professor Yu deposited a tungsten (W) thin film on a silicon oxide (SiO ₂ ) substrate, placed it in a chemical vapor deposition (CVD) system, heated it to 750 ° C., WS ₂ was grown and then subjected to additional heat treatment at 1000 ° C. for 1 hour, so that WS ₂ could be transferred onto the ITO / Glass substrate. Thus, the technique of growing WS ₂ into a thin film by using CVD can be advantageously used for the development of semiconductors or solar cells because of its large area.

As described above, chemical vapor deposition (CVD) or atomic layer deposition (ALD) is used to form a metal-containing thin film. In the case of producing a tungsten or molybdenum thin film by CVD or ALD process, Since the deposition degree and the deposition control property are determined according to the characteristics, it is necessary to develop a metal precursor having excellent characteristics. For this purpose, Korean Unexamined Patent Application Publication No. 10-2007-0073636 discloses a method for preparing a tungsten or molybdenum precursor, but there is little information about the synthesis of a precursor for forming a WS ₂ or MoS ₂ thin film . Thus, there is a desperate need to develop WS ₂ or MoS ₂ precursors with improved thermal stability, chemical reactivity, volatility, and deposition rates of metals.

Korean Laid-Open Publication No. 10-2007-0073636

&Quot; Schottky barrier solar cell based on layered semiconductor tungsten disulfide nanofilm, Applied Physics Letters, December 27, 2012. "

It is an object of the present invention to provide a novel molybdenum precursor which can improve the thermal stability and volatility and can easily produce a high quality molybdenum sulfide thin film at a low temperature.

In order to achieve the above object, the present invention provides a molybdenum precursor represented by the following general formula (1).

[Chemical Formula 1]

Wherein R ₁ is a linear or branched alkyl group having ₁ to 4 carbon atoms, R ₂ and R ₃ are each independently a linear or branched alkyl group having 1 to 10 carbon atoms, R ₄ and R ₅ are each independently a C 1- an alkyl group with a C10 linear or branched alkyl group or a C1-C10 linear or branched, of a fluoro, R ₆ is an alkyl group of a linear or branched C1-C10, n is selected from an integer ranging from 1 to 3. )

The present invention also provides a molybdenum precursor represented by the following formula (2).

(2)

Wherein R ₁ is a linear or branched alkyl group having ₁ to 4 carbon atoms, R ₂ and R ₃ are each independently a linear or branched alkyl group having 1 to 10 carbon atoms, R ₄ and R ₅ are each independently a C 1- C10 linear or branched alkyl group or a C1-C10 linear or branched fluoroalkyl group, n is selected from integers ranging from 1 to 3, and X is Cl, Br or I.

The present invention also provides a method for preparing a molybdenum precursor represented by Formula 1, which comprises reacting a compound represented by Formula 2 and a compound represented by Formula 3 below.

(3)

(In the above formula, R ₆ is an alkyl group of a linear or branched C1-C10, A is Li, Na, K, or NH _4.)

The present invention also provides a method for preparing a molybdenum precursor represented by Formula 2, which comprises reacting a compound represented by Formula 4 and a compound represented by Formula 5 below.

[Chemical Formula 4]

(In the above formula, B is Li, Na, K, or NH _4, and, R _2, R ₃ is a linear or branched alkyl group of C1-C10, each independently, R _4, R ₅ is C1-C10 each independently A linear or branched alkyl group or a C1-C10 linear or branched fluoroalkyl group, and n is an integer ranging from 1 to 3.)

[Chemical Formula 5]

(Wherein R < ₁ > is a C1-C4 linear or branched alkyl group, and X is Cl, Br or I.)

The present invention also provides a method for growing a molybdenum sulfide thin film using the molybdenum precursors of the above formulas (1) and (2).

The molybdenum precursor represented by the general formulas (1) to (2) of the present invention is a precursor containing sulfur, which has improved thermal stability and volatility and has an advantage that no additional sulfur is added during the production of the thin film. A thin film containing molybdenum sulfide can be produced.

Figure 1 is a ¹ H NMR spectrum for Mo (N ^t Bu) ₂ Cl (dmampS).
Figure 2 is TG data for Mo (N ^t Bu) ₂ Cl (dmampS).
3 is a ¹ H NMR spectrum for Mo (N ^t Bu) ₂ (S ^t Bu) (dmampS).
4 is TG data for Mo (N ^t Bu) ₂ (S ^t Bu) (dmampS).
5 is a crystal structure for Mo (N ^t Bu) ₂ (S ^t Bu) (dmampS).

The present invention relates to a molybdenum precursor represented by the following general formula (1) or (2)

[Chemical Formula 1]

Wherein R ₁ is a linear or branched alkyl group having ₁ to 4 carbon atoms, R ₂ and R ₃ are each independently a linear or branched alkyl group having 1 to 10 carbon atoms, R ₄ and R ₅ are each independently a C 1- an alkyl group with a C10 linear or branched alkyl group or a C1-C10 linear or branched, of a fluoro, R ₆ is an alkyl group of a linear or branched C1-C10, n is selected from an integer ranging from 1 to 3. )

(2)

Wherein R ₁ is a linear or branched alkyl group having ₁ to 4 carbon atoms, R ₂ and R ₃ are each independently a linear or branched alkyl group having 1 to 10 carbon atoms, R ₄ and R ₅ are each independently a C 1- C10 linear or branched alkyl group or a C1-C10 linear or branched fluoroalkyl group, n is selected from integers ranging from 1 to 3, and X is Cl, Br or I.

Wherein R ₁ is selected from CH ₃ , C ₂ H ₅ , CH (CH ₃ ) ₂ and C (CH ₃ ) ₃ , and R ₂ and R ₃ independently of one another are CH ₃ , C _{2 H 5, CH (CH 3)} 2 and C (CH ₃₎ is selected from _3, wherein R _4, R ₅ are independently CH _3, CF _3, C _{2 H 5, CH (CH 3)} 2 , and C with each other ( CH ₃ ) ₃ , and R ₆ is selected from CH ₃ , C ₂ H ₅ , CH (CH ₃ ) ₂ and C (CH ₃ ) ₃ .

Wherein R ₁ is selected from CH ₃ , C ₂ H ₅ , CH (CH ₃ ) ₂ and C (CH ₃ ) ₃ , and R ₂ and R ₃ independently of one another are CH ₃ , C _{2 H 5, CH (CH 3)} 2 and C (CH ₃₎ is selected from _3, wherein R _4, R ₅ are independently CH _3, CF _3, C _{2 H 5, CH (CH 3)} 2 , and C with each other ( CH ₃ ) ₃ is preferably used.

More specifically, the molybdenum precursor represented by Formula 1 according to the present invention may be represented by the general formula Mo (NR ₁ ) ₂ (daat) (SR) wherein R ₁ is a linear or branched alkyl group having ₁ to 4 carbon atoms, daat = dialkylaminoalkylthiolate ), And the compound can be prepared by reacting the compound represented by Formula 2 and the compound represented by Formula 3 as a starting material in an organic solvent to induce a substitution reaction.

(3)

(And wherein R, R ₆ is an alkyl group of linear or branched C1-C10, A is Li, Na, K or NH _4.)

In the general formula (3), R ₆ is preferably selected from CH ₃ , C ₂ H ₅ , CH (CH ₃ ) ₂ and C (CH ₃ ) ₃ .

The present invention also provides a method for preparing a molybdenum precursor represented by Formula 2, which comprises reacting a compound represented by Formula 4 and a compound represented by Formula 5 below.

More specifically, the molybdenum precursor represented by Formula 2 according to the present invention may be represented by the general formula Mo (NR ₁ ) ₂ (daat) X (R ₁ is a linear or branched alkyl group having ₁ to 4 carbon atoms, daat = dialkylaminoalkylthiolate, X = Cl, Br or I), and the compound can be prepared by reacting a compound represented by the following formula (4) and (5) as an starting material in an organic solvent to induce a substitution reaction.

[Chemical Formula 4]

(Wherein, B is Li, Na, K or NH _4, R _2, R ₃ are each independently a C1-C10 linear or branched alkyl group, R _4, R ₅ is a linear C1-C10, each independently Or branched C1-C10 linear or branched fluoroalkyl group, and n is selected from integers ranging from 1 to 3.)

[Chemical Formula 5]

(Wherein R < ₁ > is a C1-C4 linear or branched alkyl group, and X is Cl, Br or I.)

Wherein R ₂ and R ₃ are independently selected from CH ₃ , C ₂ H ₅ , CH (CH ₃ ) ₂ and C (CH ₃ ) ₃ , and R ₄ and R ₅ independently of one another are CH ₃ , CF ₃ , C ₂ H ₅ , CH (CH ₃ ) ₂ and C (CH ₃ ) ₃ .

In Formula 5, R ₁ is preferably selected from CH ₃ , C ₂ H ₅ , CH (CH ₃ ) ₂ and C (CH ₃ ) ₃ .

As the reaction solvent, hexane, toluene, tetrahydrofuran and the like can be used, and tetrahydrofuran can be preferably used.

A specific reaction process for producing the molybdenum precursor of the present invention can be represented by, for example, the following Reaction Schemes 1 and 2.

[Reaction Scheme 1]

Wherein R ₁ is a linear or branched alkyl group having ₁ to 4 carbon atoms, R ₂ and R ₃ are each independently a linear or branched alkyl group having 1 to 10 carbon atoms, R ₄ and R ₅ are each independently a C 1- an alkyl group with a C10 linear or branched alkyl group or a C1-C10 linear or branched, of a fluoro, R ₆ is an alkyl group of a linear or branched C1-C10, n is selected from an integer ranging from 1 to 3; A is Li, Na, K or NH _4, X is Cl, Br or I.)

[Reaction Scheme 2]

Wherein R ₁ is a linear or branched alkyl group of C ₁ -C 4, B is Li, Na, K or NH ₄ , R ₂ and R ₃ are each independently a C 1 -C 10 linear or branched alkyl group, , R ₄ and R ₅ are each independently a C1-C10 linear or branched alkyl group or a C1-C10 linear or branched fluoroalkyl group, n is selected from integers ranging from 1 to 3, X is Cl , Br, or I.)

In the above Reaction Schemes 1 and 2, a substitution reaction is carried out in a solvent such as hexane, toluene or tetrahydrofuran at room temperature for 12 hours to 24 hours, filtration under reduced pressure, and removal of the solvent from the resulting filtrate under reduced pressure, Compound. In addition, by-products may be generated in the reactions of the above Reaction Schemes 1 and 2, and they are removed by sublimation or recrystallization to obtain a high-purity novel molybdenum precursor.

In these reactions, the reactants are used in stoichiometric equivalents.

The novel molybdenum compound represented by the above formula (1) is a compound stable at room temperature and has a high affinity for an organic solvent because a non-polar alkyl group is bonded to the? -Carbon position with respect to oxygen of a ligand bonded to the metal, Can be present as a unit because it causes steric hindrance to cause interactions between sulfur and nitrogen of neighboring ligands. Due to such structural characteristics, the compound of Formula 1 has high solubility and excellent volatility in an organic solvent such as benzene, tetrahydrofuran, toluene, chloroform, etc., so that a molybdenum sulfide thin film of good quality is obtained .

When the molybdenum precursor is used to grow a molybdenum sulfide thin film, there is an advantage that no additional sulfur is added during the thin film manufacturing process.

The novel molybdenum precursor of the present invention can be suitably applied to a process for producing a molybdenum sulfide thin film using a chemical vapor deposition (CVD) or atomic layer deposition (ALD) method widely used in general thin film manufacturing processes .

The present invention may be better understood by the following examples, which are for the purpose of illustrating the invention and are not intended to limit the scope of protection defined by the appended claims.

Example

Synthesis of Molybdenum Precursor Materials

Example 1: Preparation of _{^{Mo (N t Bu) 2 Cl}} (dmampS)

To a 125 mL Schlenk flask was added Mo (N ^t Bu) ₂ Cl ₂ (dme) (1.0 g, 10.0 mmol, 1 eq) and lithium 1- (dimethylamino) -2-methylpropane-2-thiolate (4.0 g, 10.0 mmol, Lt; / RTI > After removal of the solvent under reduced pressure, hexane (30 mL) was added, filtered and then the hexane was removed under reduced pressure to obtain a red liquid compound. The obtained compound was 3.3 g, and the yield was 82%.

¹ H-NMR (C ₆ D ₆ ) of the compound Mo (N ^t Bu) ₂ Cl (dmampS) obtained above is shown in FIG.

^{_{1 H NMR (C 6 D 6}} , 300 MHz): δ 2.61 (s, 2H), 2.56 (s, 6H), 1.38 (s, 18H),

1.36 (s, 6 H).

Example 2: Preparation of Mo (N ^t Bu) ₂ (S ^t Bu) (dmampS)

(N ^t Bu) Mo obtained in Example 3 in 50 mL Herr Lenk flask ₂ Cl (dmampS) (0.5 g, 1.2 mmol, 1 eq) and sodium 2-methylpropane-2-thiolate (0.14 g, 1.2 mmol, 1 eq) were added to the reaction mixture, and tetrahydrofuran (30 mL) was added thereto. The resulting solution was filtered, and the solvent was removed under reduced pressure to obtain a yellow solid compound. Subsequently, the solution was sublimed at 60 ° C under reduced pressure to remove impurities. The obtained compound was 0.4 g, and the yield was 76%.

¹ H-NMR (C ₆ D ₆ ) of the compound Mo (N ^t Bu) ₂ (S ^t Bu) (dmampS) obtained above is shown in FIG.

^{_{1 H NMR (C 6 D 6}} , 300 MHz): δ 2.62 (s, 6H), 2.51 (s, 2H), 1.73 (s, 9H),

                          1.46 (s, 18H), 1.40 (s, 6H).

EA: calcd. (Found) C ₁₈ H ₄₁ MoN ₃ S ₂ : C, 47.04 (46.31); H, 8.99 (9.13);

                              N, 9.14 (8.87); S, 13.95 (12.34)

MS (m / z): 461

Analysis of molybdenum precursor materials

In order to confirm the specific structure of the molybdenum precursor compound synthesized in Example 2, an X-ray structure was confirmed using a Bruker SMART APEX II X-ray Diffractometer and the crystal structure thereof is shown in FIG. Through this, the structure of Mo (N ^t Bu) ₂ (S ^t Bu) (dmampS) was confirmed.

Thermogravimetric analysis (TGA) was also used to measure the thermal stability, volatility and decomposition temperature of the precursor compounds of Examples 1 and 2 above. In the TGA method, argon gas was introduced at a pressure of 1.5 bar / min while warming the product to 900 ° C at a rate of 10 ° C / minute.

TGA graphs of the molybdenum precursor compounds synthesized in Examples 1 and 2 are shown in FIG. 2 and FIG. 4, respectively.

As shown in FIG. 2, the molybdenum precursor compound obtained in Example 1 exhibited a mass reduction at about 110 ° C., a mass reduction of at least 64% at 230 ° C., and a mass reduction of at least 73% at 385 ° C.

As shown in FIG. 4, the molybdenum precursor compound synthesized in Example 2 was reduced in mass at around 175 ° C, a mass reduction of more than 57% was observed at 245 ° C, and a mass reduction of more than 69% was observed at 407 ° C .

Claims (8)

A molybdenum precursor represented by the following formula (1)
[Chemical Formula 1]

Wherein R ₁ is a linear or branched alkyl group having ₁ to 4 carbon atoms, R ₂ and R ₃ are each independently a linear or branched alkyl group having 1 to 10 carbon atoms, R ₄ and R ₅ are each independently a C 1- an alkyl group with a C10 linear or branched alkyl group or a C1-C10 linear or branched, of a fluoro, R ₆ is an alkyl group of a linear or branched C1-C10, n is selected from an integer ranging from 1 to 3. ) A molybdenum precursor represented by the following formula (2): < EMI ID =
(2)

Wherein R ₁ is a linear or branched alkyl group having ₁ to 4 carbon atoms, R ₂ and R ₃ are each independently a linear or branched alkyl group having 1 to 10 carbon atoms, R ₄ and R ₅ are each independently a C 1- C10 linear or branched alkyl group or a C1-C10 linear or branched fluoroalkyl group, n is selected from integers ranging from 1 to 3, and X is Cl, Br or I. The method according to claim 1,
Wherein R ₁ is selected from CH ₃ , C ₂ H ₅ , CH (CH ₃ ) ₂ and C (CH ₃ ) ₃ and R ₂ and R ₃ independently of one another are CH ₃ , C ₂ H ₅ , CH _{3) 2} and C (CH ₃₎ is selected from _3, wherein R _4, R ₅ are independently CH _3, CF _3, C ₂ H _5, CH (CH _{3) 2} and C (CH ₃₎ selected from the _third one another And R ₆ is selected from CH ₃ , C ₂ H ₅ , CH (CH ₃ ) _2, and C (CH ₃ ) ₃ . The method of claim 2,
Wherein R ₁ is selected from CH ₃ , C ₂ H ₅ , CH (CH ₃ ) ₂ and C (CH ₃ ) ₃ and R ₂ and R ₃ independently of one another are CH ₃ , C ₂ H ₅ , CH _{3) 2} and C (CH ₃₎ is selected from _3, wherein R _4, R ₅ are independently CH _3, CF _3, C ₂ H _5, CH (CH _{3) 2} and C (CH ₃₎ selected from the _third one another ≪ / RTI > wherein the precursor is a molybdenum precursor. A process for producing a molybdenum precursor represented by formula (1) as set forth in claim 1, which comprises reacting a compound represented by formula (2) of claim 2 with a compound represented by formula (3)
(3)

(In the above formula, R ₆ is an alkyl group of a linear or branched C1-C10, A is Li, Na, K, or NH _4.) A process for producing a molybdenum precursor represented by formula (2), comprising reacting a compound represented by the following formula (4) and a compound represented by the following formula (5)
[Chemical Formula 4]

(In the above formula, B is Li, Na, K, or NH _4, and, R _2, R ₃ is a linear or branched alkyl group of C1-C10, each independently, R _4, R ₅ is C1-C10 each independently A linear or branched alkyl group or a C1-C10 linear or branched fluoroalkyl group, and n is an integer ranging from 1 to 3.)
[Chemical Formula 5]

(Wherein R < ₁ > is a C1-C4 linear or branched alkyl group, and X is Cl, Br or I.) A method for growing a metal thin film using the molybdenum precursor of claim 1 or 2. The method of claim 7,
Wherein the thin film growth process is performed by chemical vapor deposition (CVD) or atomic layer deposition (ALD).

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