• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.29-32
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• 2001

Hydrogen passivation of Si nanocrystals identifies luminescence mechanism indirectly. Si nanocrystallites thin films on p-type (100) Si substrate have been fabricated by pulsed laser deposition technique using a Nd:YAG laser After deposition, Si nanocrystallites thin films have been annealed at 600$^{\circ}C$ and 760$^{\circ}C$ in nitrogen ambient, respectively. Hydrogen passivation was subsequently performed at 500$^{\circ}C$ in forming gas (95 % N$_2$ + 5 % H$_2$) for an 1 hour. We report the photoluminescnece(PL) property of Si thin films by the hydrogen passivation. The luminescence mechanism of Si nanocrystallites has also been investigated.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.51 no.6
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• pp.236-239
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• 2002

Si nanocrystallites thin films on P-type (100) Si substrate have been fabricated by pulsed laser deposition using a Nd:YAG laser. After deposition, samples were annealed in several environmental gases ;It the temperature range of 400 to $800^{\circ}C$ Hydrogen passivation was then performed in the forming gas (95 % $N_2$ + 5 % $H_2$) for 1 hr. Strong violet-indigo photoluminescence has been observed at room temperature on nitrogen ambient-annealed Si nanocrystallites. We report the variation of photoluminescence (PL) properties of Si thin films by changing annealing temperatures and by using hydrogen passivation. The results could suggest that the origin of violet-indigo PL should be related to the Quantum size effect of Si nanocrystallite.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07b
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• pp.1033-1036
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• 2004

Si nanocrystallites thin films on p-type (100) Si substrate have been fabricated by pulsed laser deposition using a Nd:YAG laser. After deposition, samples were annealed at the temperatures of 400 to $800^{\circ}C$. Hydrogen passivation was then performed in the forming gas (95% $N_2$ + 5% $H_2$) for 1 hr. Strong violet-indigo photoluminescence has been observed at room temperature from nitrogen ambient-annealed Si nanocrystallites. The variation of photoluminescence (PL) Properties of Si nanocrystallites thin films has been investigated depending on annealing temperatures with hydrogen passivation. From the results of PL, Fourier transform infrared (FTIR), and high-resolution transmission electron microscopy (HRTEM) measurements, it is observed that the origin of violet-indigo PL from the nanocrystalline silicon in the silicon oxide film is related to the quantum size effect of Si nanocrystallites and oxygen vacancies in the SiOx(x : 1.6-1.8) matrix affects the emission intensity.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.04b
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• pp.38-41
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• 2002

The variation of photoluminescence(PL) properties of Si thin films was investigated by changing deposition temperatures, Si-rich silicon oxide films on p-type (100) Si substrate have been fabricated by pulsed laser deposition(PLD) technique using a Nd:YAG laser. During deposition, the substrates were kept at the temperature range of room temperature(RT) to $400^{\circ}C$. After deposition, samples were annealed at $800^{\circ}C$ in nitrogen ambient, Strong Blue PL has been observed on RT-deposited Si nanocrystallites. When the deposition temperature was increased over $100^{\circ}C$, PL intensities abruptly decreased. The experimental results show the growing mechanism of Si nanocrystallites by PLD.

• Proceedings of the KIEE Conference
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• 2000.11c
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• pp.411-412
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• 2000

Si nanocrstallites on p-tyre (100) Si substrate have been fabricated by pulsed laser deposition technique using a Nd:YAG laser with the wavelength of 355, 532 and 1064 nm. The base vacuum in the chamber was down to $10^{-5}$ Torr and the pressure of the gas during deposition was varied from 1 to 3 Torr. After deposition, Si nanocrystallites have been annealed at $N_2$ gas. Nitrogen have been used as ambient gases. Strong blue and green luminescence from Si nanocrystallites has been observed in room temperature by photoluminescence and its peak energies shift to green when the wavelength is increased from 355-1064 nm

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.04a
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• pp.88-91
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• 2003

Si nanocrystallites thin films have been fabricated by pulsed laser deposition using a Nd:YAG laser. After deposition, samples were annealed at the temperature range of 400 to $800^{\circ}C$. Hydrogen passivation was then performed in the forming gas ($95%N_{2}+5%H_{2}$) at $500^{\circ}C$. Strong violet-indigo photoluminescence has been observed at room temperature on nitrogen ambient-annealed Si nanocrystallites. As a result of photoluminescence spectra and infrared absorption spectra, we conclude that the violet-indigo PL efficiency is related with oxygen vacancy in the $SiO_x$(x= 1.6-1.8) matrix.

• Journal of the Korean Ceramic Society
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• v.34 no.9
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• pp.941-948
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• 1997

CuCl nanocrystallites dispersed nonlinear optical silica and borosilicate glasses were fabricated by sol-gel process. CuCl powder was dissolved in TEOS(Si(OC2H5)4) and TMB((CH3O)3B), precursors of silica and borosilicate glasses, with ethanol, water and HCl, and precipitated through the heat treatment in the matrix glass. The optical properties of CuCl doped glasses were measured using the spectrophotometer at room temperature and low temperature(77K); Z1, 2 and Z3 exciton peaks from the absorption spectra, were observed at about 370 nm and 380 nm, respectively. The average radius of nanocrystallites, calculated from the blue shift of Z3 excitons, was measured according to annealing temperature and time. The precipitation temperature of CuCl nanocrystallites was decreased when boron was added to silica glass. Increase of annealing temperature and time made average radius of nanocrystallites saturated about 2 nm.

• Korean Journal of Crystallography
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• v.14 no.2
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• pp.56-61
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• 2003

Nanocrystalline hydrogenated silicon (nc-Si : H) thin films were deposited at room temperature by plasma enhanced chemical vapor deposition (PECVD): a mixture of SiH₄ and H₂ gas was introduced into the evacuated reaction chamber. When the H₂ gas flow rate was low, the density of Si-H₃ bonds was high in the films. On the other hand, when the H₂ gas flow rate was high, e.g., 100 sccm, a large number of Si-H bonds contributed to the passivation of the surface of the large volume of Si nanocrystallites. The relative fraction of the Si-H₃ and Si-H₂ bonds in the amorphous matrix varied sensitively with the H₂ gas flow rate. The variation was associated with the change in the intensity as well as the wavelength of the main PL peaks, indicating the change in the total volume as well as the size of the Si nanocrystallites in the films.

• 한국전자현미경학회:학술대회논문집
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• 2004.11a
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• pp.64-65
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• 2004

• 한국전자현미경학회:학술대회논문집
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• 2005.05a
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• pp.98-99
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• 2005