KR101503031B1 - Lead precursors with aminothiolate, preparation method thereof and process for the formation of thin films using the same - Google Patents

Abstract

(상기 식에서, R₁, R₂는 각각 독립적으로 C1-C10의 선형 또는 분지형 알킬기이고, R₃, R₄는 각각 독립적으로 C1-C10의 선형 또는 분지형의 알킬기 또는 C1-C10의 선형 또는 분지형의 플루오로알킬기이고, n은 1 내지 3 범위의 정수에서 선택된다.) The present invention relates to a lead precursor represented by the following general formula (1), wherein the lead precursor is a precursor containing sulfur, has improved thermal stability and volatility, and has the advantage of not requiring addition of sulfur during the production of a thin film, A high quality lead sulfide thin film can be easily produced.
[Chemical Formula 1]

Wherein R ₁ and R ₂ are each independently a C 1 -C 10 linear or branched alkyl group and R ₃ and R ₄ are each independently a C 1 -C 10 linear or branched alkyl group or a C 1 -C 10 linear or branched Branched fluoroalkyl group, and n is selected from integers ranging from 1 to 3.)

Description

TECHNICAL FIELD [0001] The present invention relates to a lead precursor using aminothiolate, a method for producing the lead precursor, and a method for forming a thin film using the same. BACKGROUND OF THE INVENTION [0002]

More particularly, the present invention relates to a lead precursor having improved thermal stability and volatility and capable of easily producing a thin film of lead sulfide at a low temperature, a method for producing the lead precursor, and a method for producing a lead sulfide thin film using the lead precursor .

Nanoparticles of semiconductor materials have been identified as materials that can be applied to a variety of fields, such as biological labels and diagnostics, light emitting diodes, electrical devices, photovoltaic devices, lasers, and single electron transistors. In particular, lead sulfide (PbS), which is widely used in cation selective sensors, photography, IR detectors, and solar absorbers, has a very narrow band gap energy (0.41 eV at 300 K) and a large bore radius Is an important direct band gap semiconductor. Since the third-order nonlinear optical response is expected to be 30 times higher than that of gallium arsenide (GaAs) and 1,000 times higher than that of cadmium selenium (CdSe), the nano lattice of lead sulfide (PbS) requires high photon and optical switching devices .

Chemical vapor deposition (CVD) or atomic layer deposition (ALD) is used for forming the thin film using the lead sulfide (PbS). When the thin film of lead sulfide is manufactured by the CVD or ALD process as described above , The degree of deposition and the deposition control characteristics are determined according to the characteristics of the metal precursor, and therefore it is necessary to develop a metal precursor having excellent characteristics. For this purpose, USP Publication No. 2008-0102313 discloses a lead sulfide precursor using a sulfonic acid or the like, but there have been few studies on the synthesis of specific precursors. Accordingly, there is a desperate need to develop a lead sulfide (PbS) precursor with improved thermal stability, chemical reactivity, volatility, and deposition rate of metals.

U.S. Publication No. 2008-0102313 A

It is an object of the present invention to provide a novel lead precursor which is improved in thermal stability and volatility and which is capable of easily producing a lead sulfide thin film at a low temperature.

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

[Chemical Formula 1]

Wherein R ₁ and R ₂ are each independently a C 1 -C 10 linear or branched alkyl group and R ₃ and R ₄ are each independently a C 1 -C 10 linear or branched alkyl group or a C 1 -C 10 linear or branched Branched fluoroalkyl group, and n is selected from integers ranging from 1 to 3.)

The present invention also provides a process for preparing a lead precursor represented by the above formula (1), which comprises reacting a compound represented by the following formula (2) and a compound represented by the following formula (3).

(2)

(Wherein, M is Li, Na, and K, or NH _4, R _1, R ₂ are each independently a C1-C10 linear or branched alkyl group, R _3, R ₄ 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.)

(3)

PbX ₂

(Wherein X is Cl, Br or I).

The present invention also provides a method of growing a lead sulfide thin film using the lead precursor of Formula 1 above.

The lead precursor represented by Formula 1 of the present invention is a precursor containing sulfur and has improved thermal stability and volatility and has an advantage that no additional sulfur is added during the production of the thin film, Can be manufactured.

Figure 1 is a ¹ H NMR spectrum for Pb (dmampS) ₂ .
2 is TG data for Pb (dmampS) ₂ .
3 is a crystal structure for Pb (dmampS) ₂ .

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

[Chemical Formula 1]

Wherein R ₁ and R ₂ are each independently a C 1 -C 10 linear or branched alkyl group and R ₃ and R ₄ are each independently a C 1 -C 10 linear or branched alkyl group or a C 1 -C 10 linear or branched Branched fluoroalkyl group, and n is selected from integers ranging from 1 to 3.)

Wherein R ₁ and R ₂ are independently selected from CH ₃ , C ₂ H ₅ , CH (CH ₃ ) ₂ and C (CH ₃ ) ₃ , and R ₃ and R ₄ are independently a _{CH 3, CF 3, C 2} H 5, CH (CH 3) is preferably used selected from ₂ and C (CH _{3) 3.}

The lead precursor represented by the formula (1) according to the present invention may be represented by a general formula Pb (daat) ₂ (daat = dialkylaminoalkylthiolate), and the lead precursor represented by the formula (1) Can be produced by reacting a displayed compound (M (daat)) with a compound (PbX ₂ ) represented by the general formula ( ₃ ) in an organic solvent to induce a substitution reaction. More specific examples of the daat include 1- (dimethylamino) -2-methylpropane-2-thiolate, that is, dmampS.

(2)

(Wherein, M is Li, Na, and K, or NH _4, R _1, R ₂ are each independently a C1-C10 linear or branched alkyl group, R _3, R ₄ 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.)

(3)

PbX ₂

(Wherein X is Cl, Br or I).

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

A specific reaction process for preparing the lead precursor of the present invention can be represented by the following reaction formula (1).

[Reaction Scheme 1]

Wherein R ₁ and R ₂ are each independently a C 1 -C 10 linear or branched alkyl group and R ₃ and R ₄ are each independently a C 1 -C 10 linear or branched alkyl group or a C 1 -C 10 linear or branched N is an integer ranging from 1 to 3; M is Li, Na, K, or NH ₄ ; and X is Cl, Br, or I.

According to Scheme 1, the substitution reaction is carried out in a solvent such as hexane, toluene, tetrahydrofuran, diethyl ether at room temperature for 15 hours to 24 hours, the solvent is removed under reduced pressure, and the obtained solid compound is purified by using hexane After melting and filtration, the filtrate is removed under reduced pressure to give a pale yellow solid compound. In addition, by-products may be formed in the reaction of Scheme 1, and they may be removed by sublimation or recrystallization to obtain a new lead precursor of high purity.

The reactants in this reaction are used in stoichiometric equivalents.

The novel lead precursor represented by Formula 1 is a pale yellow solid which is stable at room temperature and is thermally stable and has good volatility.

When the lead sulfide thin film is grown using the lead precursor, there is an advantage that no additional sulfur is added during the thin film manufacturing process.

The lead precursor of the present invention is preferably used as a precursor for the production of a thin film of lead sulfide, which uses chemical vapor deposition (CVD) or atomic layer deposition (ALD), which is 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 lead precursor materials

Example 1: Preparation of Pb (dmampS) ₂

To a 100 mL Schlenk flask was added PbCl ₂ (2.0 g, 7.2 mmol, 1 eq) and lithium 1- (dimethylamino) -2-methylpropane-2-thiolate (2.0 g, 14.4 mmol, 2 eq) mL) was added thereto, followed by stirring for 24 hours. The resulting solution was filtered, and the solvent was removed under reduced pressure to obtain a yellow solid compound, which was then sublimed under reduced pressure at 80 DEG C to remove impurities. The obtained compound was 2.7 g, and the yield was 80%.

¹ H-NMR (C ₆ D ₆ ) of the obtained compound Pb (dmampS) ₂ is shown in FIG.

^{_{1 H NMR (C 6 D 6}} , 300 MHz): δ 2.74 (s, 2H), 2.21 (s, 6H), 1.70 (s, 6H).

. EA: calcd (found) PbC 12 H 28 N 2 S 2: C, 30.56 (30.93); H, 5.98 (6.09);

N, 5.94 (6.26); S, 13.60 (13.98)

Analysis of lead precursor materials

In order to confirm the specific structure of the precursor compound synthesized in Example 1, a crystal structure (X-ray structure) was confirmed using a Bruker SMART APEX II X-ray Diffractometer and is shown in FIG. The structure of Pb (dmampS) ₂ was confirmed through this.

Thermogravimetric analysis (TGA) was also used to measure the thermal stability, volatility and decomposition temperature of the precursor compound of Example 1 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.

As shown in FIG. 2, the lead precursor compound obtained in Example 1 showed a mass reduction at around 201 DEG C and a mass decrease of more than 57% at 261 DEG C. Through this, it was confirmed that the TG graph T _1/2 is 253 ℃.

Claims (5)

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

Wherein R ₁ and R ₂ are independently selected from CH ₃ , C ₂ H ₅ , CH (CH ₃ ) ₂ and C (CH ₃ ) ₃ , and R ₃ and R ₄ independently of one another are CH ₃ , CF ₃ , C ₂ H ₅ , CH (CH ₃ ) ₂ and C (CH ₃ ) ₃ , and n is selected from integers ranging from 1 to 3.) delete A process for producing a lead precursor represented by the general formula (1), comprising reacting a compound represented by the following general formula (2) and a compound represented by the following general formula (3)
(2)

(Wherein, M is selected from Li, Na, K or NH ₄ and, R _1, R ₂ are each independently _{CH 3, C 2 H 5,} CH (CH 3) 2 and C (CH _{3) 3,} Wherein R ₃ and R ₄ are independently selected from CH ₃ , CF ₃ , C ₂ H ₅ , CH (CH ₃ ) ₂ and C (CH ₃ ) ₃ and n is an integer ranging from 1 to 3. )
(3)
PbX ₂
(Wherein X is Cl, Br or I). A method of growing a lead sulfide thin film using the lead precursor of claim 1. The method of claim 4,
Wherein the thin film growth process is performed by chemical vapor deposition (CVD) or atomic layer deposition (ALD).

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