Process for producing semiconductor nanocrystal cores, core-shell, core-buffer-shell, and multiple layer systems in a non-coordinating solvent utilizing in situ surfactant generation

1. A process for producing III-V or II-VI nanocrystals comprising:

(a) reacting a compound of formula (I) with a compound of formula (II)

ML n   (I)

E(SiR 3 ) n   (II)

wherein:

n is 3, and M is a Group III metal, and E is a Group V element, or

n is 2, and M is a Group II, and E is a Group VI element;

L is a ligand; and

R is selected from the group consisting of H, —(CH 2 ) m CH 3 , —(C(CH 3 ) 2 ) m CH 3 , —(C(CH 3 ) 2 ) m (CH 2 ) z CH 3 , —(CH 2 ) m (C(CH 3 ) 2 ) z CH 3 , and any combination thereof, wherein m and z are real numbers,

in the absence of any surfactant, ligand, or coordinating solvent under conditions effective to produce homogeneous nucleation of seed III-V or II-VI nuclei and a compound of formula (III)

LSiR 3   (III); and

(b) permitting reaction to occur between the seed III-V or II-VI nuclei and the compound of formula (III) under conditions effective to produce III-V or II-VI nanocrystals.

2. The process as claimed in claim 1 , wherein M is selected from the group consisting of Al, Ga, and In, and E is selected from the group consisting of N, P, As, and Sb.

3. The process as claimed in claim 1 , wherein M is selected from the group consisting of Cd, Zn, Mg, and Hg, and E is selected from the group consisting of O, S, Se, and Te.

4. The process as claimed in claim 1 , wherein L is selected from the group consisting of —E 1 R 1 2 , —E 2 R 1 , —E 2 C(O)R 1 , and beta-diketonates or beta-diketonate derivatives, wherein:

E 1 is a Group V element;

E 2 is a Group VI element; and

R 1 is selected from the group consisting of H, —(CH 2 ) m CH 3 , —(C(CH 3 ) 2 ) m CH 3 , —(C(CH 3 ) 2 ) m (CH 2 ) z CH 3 , —(CH 2 ) m (C(CH 3 ) 2 ) z CH 3 , and any combination thereof, wherein m and z are real numbers.

5. The process as claimed in claim 1 , wherein R is alkyl.

6. The process as claimed in claim 5 , wherein R is methyl.

7. The process as claimed in claim 1 , wherein the compound of formula (I) is present in solution with a non-coordinating solvent.

8. The process as claimed in claim 7 , wherein the non-coordinating solvent is selected from the group consisting of benzene, toluene, xylene, decane, and octadecene.

9. A process for producing nanocrystals having multiple layers of III-V or II-VI material comprising:

(a) reacting a compound of formula (I) with a compound of formula (II)

ML n   (I)

E(SiR 3 ) n   (II)

wherein:

n is 3, and M is a Group III metal, and E is a Group V element, or

n is 2, and M is a Group II, and E is a Group VI element;

L is a ligand; and

R is selected from the group consisting of H, —(CH 2 ) m CH 3 , —(C(CH 3 ) 2 ) m CH 3 , —(C(CH 3 ) 2 ) m (CH 2 ) z CH 3 , —(CH 2 ) m (C(CH 3 ) 2 ) z CH 3 , and any combination thereof, wherein m and z are real numbers,

in the absence of any surfactant, ligand, or coordinating solvent under conditions effective to produce homogeneous nucleation of seed III-V or II-VI nuclei and a compound of formula (III)

LSiR 3   (III);

(b) permitting reaction to occur between the seed III-V or II-VI nuclei and the compound of formula (III) under conditions effective to produce III-V or II-VI nanocrystals; and

(c) reacting the product of step (b) with a source of a Group III metal and a Group V element, or with a source of a Group II metal and a Group VI element, under conditions effective to produce nanocrystals having multiple layers of III-V or II-VI material.

10. The method according to claim 9 , wherein the multiple layers of III-V or II-VI material comprise the same material.

11. The method according to claim 9 , wherein the multiple layers of III-V or II-VI material comprise different materials.

12. The method as claimed in claim 9 , further comprising after step (c), one or more sequential reacting steps comprising reacting the product of the previous step with a source of a Group III metal and a Group V element, or with a source of a Group II metal and a Group VI element, under conditions effective to produce nanocrystals having multiple layers of III-V or II-VI material.

13. The method according to claim 12 , wherein the multiple layers of III-V or II-VI material comprise the same material.

14. The method according to claim 12 , wherein the multiple layers of III-V or II-VI material comprise different materials.

15. The process as claimed in claim 9 , wherein M is selected from the group consisting of Al, Ga, and In, and E is selected from the group consisting of N, P, As, and Sb.

16. The process as claimed in claim 9 , wherein M is selected from the group consisting of Cd, Zn, Mg, and Hg, and E is selected from the group consisting of O, S, Se, and Te.

17. The process as claimed in claim 9 , wherein L is selected from the group consisting of —E 1 R 1 2 , —E 2 R 1 , —E 2 C(O)R 1 , and beta-diketonates or beta-diketonate derivatives, wherein:

E 1 is a Group V element;

E 2 is a Group VI element; and

R 1 is selected from the group consisting of H, —(CH 2 ) m CH 3 , —(C(CH 3 ) 2 ) m CH 3 , —(C(CH 3 ) 2 ) m (CH 2 ) z CH 3 , —(CH 2 ) m (C(CH 3 ) 2 ) z CH 3 , and any combination thereof, wherein m and z are real numbers.

18. The process as claimed in claim 9 , wherein R is alkyl.

19. The process as claimed in claim 18 , wherein R is methyl.

20. The process as claimed in claim 9 , wherein the compound of formula (I) is present in solution with a non-coordinating solvent.

21. The process as claimed in claim 20 , wherein the non-coordinating solvent is selected from the group consisting of benzene, toluene, xylene, decane, and octadecene.

22. The process as claimed in claim 9 , wherein the source of a Group III metal or the source of a Group II metal is a compound of formula (IV):

MX n   (IV)

wherein

X is selected from the group consisting of Cl, carboxylate, carbonate, —E 1 R 1 2 , —E 2 R 1 , —E 2 C(O)R 1 , and beta-diketonates or beta-diketonate derivatives, wherein:

E 1 is a Group V element;

E 2 is a Group VI element; and

R 1 is selected from the group consisting of H, —(CH 2 ) m CH 3 , —(C(CH 3 ) 2 ) m CH 3 , —(C(CH 3 ) 2 ) m (CH 2 ) z CH 3 , —(CH 2 ) m (C(CH 3 ) 2 ) z CH 3 , and any combination thereof, wherein m and z are real numbers.

23. A process for producing nanocrystals having multiple layers of III-V or II-VI material comprising:

(a) providing a supply of seed III-V or II-VI nanocrystals; and

(b) reacting the seed III-V or II-VI nanocrystals with a source of a Group III metal and a Group V element, or with a source of a Group II metal and a Group VI element in the absence of any surfactant, ligand, or coordinating solvent, under conditions effective to produce nanocrystals having multiple layers of III-V or II-VI material.

24. The method according to claim 23 , wherein the multiple layers of III-V or II-VI material comprise the same material.

25. The method according to claim 23 , wherein the multiple layers of III-V or II-VI material comprise different materials.

26. The method as claimed in claim 23 , further comprising after step (b), one or more sequential reacting steps comprising reacting the product of the previous step with a source of a Group III metal and a Group V element, or with a source of a Group II metal and a Group VI element, under conditions effective to produce nanocrystals having multiple layers of III-V or II-VI material.

27. The method according to claim 26 , wherein the multiple layers of III-V or II-VI material comprise the same material.

28. The method according to claim 26 , wherein the multiple layers of III-V or II-VI material comprise different materials.

29. The process as claimed in claim 23 , wherein the source of a Group III metal or the source of a Group II metal is a compound of formula (IV):

MX n   (IV)

wherein

n is 3, and M is a Group III metal, or

n is 2, and M is a Group II;

X is selected from the group consisting of Cl, carboxylate, carbonate, —E 1 R 1 2 , —E 2 R 1 , —E 2 C(O)R 1 , and beta-diketonates or beta-diketonate derivatives, wherein:

E 1 is a Group V element;

E 2 is a Group VI element; and

R 1 is selected from the group consisting of H, —(CH 2 ) m CH 3 , —(C(CH 3 ) 2 ) m CH 3 , —(C(CH 3 ) 2 ) m (CH 2 ) z CH 3 , —(CH 2 ) m (C(CH 3 ) 2 ) z CH 3 , and any combination thereof, wherein m and z are real numbers.

30. A process for producing a compound of formula (VII)

M 1 (ER 3 x ) 3 , comprising:

(a) reacting a compound of formula (V) with a compound of formula (VI)

M 1 (C 5 R 2 k H 5-k ) 3   (V)

HER 3 x   (VI)

wherein:

M 1 is a Group III metal;

R 2 is selected from the group consisting of H, —(CH 2 ) m CH 3 , —(C(CH 3 ) 2 ) m CH 3 , —(C(CH 3 ) 2 ) m (CH 2 ) z CH 3 , —(CH 2 ) m (C(CH 3 ) 2 ) z CH 3 , and any combination thereof, wherein m and z are real numbers;

k is 0–5;

x is 2, and E is a Group V element or

x is 1, and E is a Group VI element; and

R 3 is selected from the group consisting of H, —(CH 2 ) m CH 3 , —(C(CH 3 ) 2 ) m CH 3 , —(C(CH 3 ) 2 ) m (CH 2 ) z CH 3 , —(CH 2 ) m (C(CH 3 ) 2 ) z CH 3 , and any combination thereof, wherein m and z are real numbers, and when x is 1, R 3 may additionally be C(O)R 3 ,

under conditions effective to produce a compound of formula (VII).

31. The process as claimed in claim 30 , wherein M 1 is selected from the group consisting of Al, Ga, and In.

32. The process as claimed in claim 30 , wherein x is 2, and E is selected from the group consisting of N, P, As, and Sb.

33. The process as claimed in claim 30 , wherein x is 1, and E is selected from the group consisting of O, S, Se, and Te.

34. The process as claimed in claim 30 , wherein the compound of formula (V) is selected from the group consisting of In(C 5 H 5 ) 3 , In(C 5 H 4 Me) 3 , In(C 5 Me 5 ) 3 , and In(C 5 H 4 (CH 2 C(CH 3 ) 3 ).

35. The process as claimed in claim 30 , wherein the compound of formula (VI) is selected from the group consisting of myristic acid, stearic acid, lauric acid, decanoic acid, 1-octadecanol, 1-octadecanethiol, dodecylamine, dioctadecylamine, dioctylphosphine, and diocyadecylarsine.

36. The process as claimed in claim 30 , wherein the compound of formula (VII) is selected from the group consisting of In(Myristate) 3 , In(Laurate) 3 , In(Stearate) 3 , In(Decanoate) 3 , In(octadecanoate) 3 , In(octadecanethiolate) 3 , In(N(C 12 H 25 ) 2 ) 3 , In(N(C 18 H 37 ) 2 ) 3 , In(P(C 18 H 37 ) 2 ) 3 , and In(As(C 18 H 37 ) 2 ) 3 .