synthesis manifests many advantages over the hydrothermal method for preparing non-oxide materials. For example, it is effective in the preparation of nitride
nanomaterials, which commonly cannot be prepared by the hydrothermal method.
Recently, quantum-confined 5 nm GaP and 8 nm InP nanocrystals were hydrothermally synthesized at 120–160
C [33]. As shown in Figure 7.6B an emission
peak at 850 nm (1.55 eV) was observed in the photoluminescence spectrum of the
as-prepared InP nanocrystals, which revealed the blue shift of the band gap with
0.2 eV, for GaP nanocrystals, an emission peak at 400 nm (3.1 eV) was also found
(Figure 7.6A) which shows a pronounced quantum confinement effect.
7.2
Solvothermal Synthesis of III–V Nanomaterials
GaN is a direct band-gap semiconductor, which has potential applications in lightemitting devices in the visible and ultraviolet region. Wurtzite-type GaN was traditionally prepared via a gas-phase reaction in ammonia at 600–1000
C [34]. It can
also be produced via pyrolysis of single source precursors, such as [H 2 GaNH 2 ] 3 ,
Ga(C 2 H 5 ) 3 NH 3 , which already have a GaaN bond, followed by treatment at temperatures >500
C [35]. On the other hand, nitrides of lanthanide or transition
metals could be synthesized through a solid-state metathesis reaction (Reaction (1))
[36]:
MCl n þ Li 3 N !
600a1100
C MN þ 3LiCl
ð1Þ
GaCl 3 þ Li 3 N !
280
C
benzene
GaN þ 3LiCl
ð2Þ
Fig. 7.6. Absorption and photoluminescence (PL) spectra of
as-prepared products, GaP nanocrystals (A) and InP
nanocrystals (B).
7.2 Solvothermal Synthesis of III–V Nanomaterials 175
nanomaterials, which commonly cannot be prepared by the hydrothermal method.
Recently, quantum-confined 5 nm GaP and 8 nm InP nanocrystals were hydrothermally synthesized at 120–160
C [33]. As shown in Figure 7.6B an emission
peak at 850 nm (1.55 eV) was observed in the photoluminescence spectrum of the
as-prepared InP nanocrystals, which revealed the blue shift of the band gap with
0.2 eV, for GaP nanocrystals, an emission peak at 400 nm (3.1 eV) was also found
(Figure 7.6A) which shows a pronounced quantum confinement effect.
7.2
Solvothermal Synthesis of III–V Nanomaterials
GaN is a direct band-gap semiconductor, which has potential applications in lightemitting devices in the visible and ultraviolet region. Wurtzite-type GaN was traditionally prepared via a gas-phase reaction in ammonia at 600–1000
C [34]. It can
also be produced via pyrolysis of single source precursors, such as [H 2 GaNH 2 ] 3 ,
Ga(C 2 H 5 ) 3 NH 3 , which already have a GaaN bond, followed by treatment at temperatures >500
C [35]. On the other hand, nitrides of lanthanide or transition
metals could be synthesized through a solid-state metathesis reaction (Reaction (1))
[36]:
MCl n þ Li 3 N !
600a1100
C MN þ 3LiCl
ð1Þ
GaCl 3 þ Li 3 N !
280
C
benzene
GaN þ 3LiCl
ð2Þ
Fig. 7.6. Absorption and photoluminescence (PL) spectra of
as-prepared products, GaP nanocrystals (A) and InP
nanocrystals (B).
7.2 Solvothermal Synthesis of III–V Nanomaterials 175