• Bulletin of the Korean Chemical Society
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• v.35 no.12
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• pp.3601-3608
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• 2014

RGB light emitting ZnSe based nanocrystals: ZnSe (blue), ZnSe:Cu (green) and ZnSe:Mn (red) were synthesized by capping the surface of the nanocrystals with oleic acid. The obtained nanocrystal powders were characterized by using XRD, HR-TEM, ICP-AES, FT-IR, and FT-Raman spectroscopies. The optical properties were also measured by UV/Vis and photoluminescence (PL) spectroscopies. The PL spectra showed broad emission peaks at 471 nm (ZnSe), 530 nm (ZnSe:Cu) and 665 nm (ZnSe:Mn), with relative PL efficiencies in the range of 0.7% to 5.1% compared to a reference organic dye standard. The measured average particle sizes from the HR-TEM images for those three nanocrystals were 4.5 nm on average, which were also supported well by the Debye-Scherrer calculations. The elemental compositions of the ZnSe based nanocrystals were determined by ICP-AES analyses. Finally, the drawn CIE diagram showed the color coordinates of (0.15, 0.16) for ZnSe, (0.22, 0.57) for ZnSe:Cu, and (0.62, 0.35) for ZnSe:Mn respectively, which were fairly well matched to that of the RGB color standards.

• Korean Journal of Materials Research
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• v.7 no.10
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• pp.914-918
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• 1997

MBS에 의해(001)GaAs기판 위에 성장된 Zn$_{1-x}$Co$_{x}$Se(x=1.0, 7.4, 9.5 %)반도체 박막과 (ZnSe/FeSe)반도체 초격자 박막의 미세구조를 투과전자현미경을 이용하여 연구하였다. Zn$_{1-x}$Co$_{x}$Se 박막 시편의 경우, 박막과 기판 사이의 격자 불일치때문에 a/2<110>형태의 버거즈 벡터를 가지는 부정합 전위를 관찰하였다. 모든 Zn$_{1-x}$Co$_{x}$Se 박막과 기판의 계면은 뚜렷이 구별되었고, 계면에서 산화물이나 이물질이 존재하지 않았다. 또한, (ZnSe/FeSe)초격자를 성장시키기 전에 GaAs기판 위에 ZnSe바닥층을 넣음으로써 고품질의 (ZnSe/FeSe)초격자를 얻었다. (ZnSe/FeSe)초격자에 있는 FeSe는 섬아연광 결정구조로 존재하였다.

• Applied Microscopy
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• v.27 no.3
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• pp.235-241
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• 1997

The microstructure of intermixed $Zn_{1-x}Fe_xSe$ layers in the (ZnSe/FeSe) superstrates grown on (00l) GaAs substrates has been investigated by high -resolution transmission electron microscopy and computer simulations of lattice images. Computer image simulations have been performed by the multislice method under various sample thicknesses and defocusing conditions. The simulated lattice images were compared with the experimental lattice images. Also, CuAu-I type ordering was often observed in the intermixed $Zn_{1-x}Fe_xSe$ alloys. This CuAu-I type ordered structure consists of alternating ZnSe and FeSe monolayers along the <100> and <110> directions.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.120-121
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• 2009

Single crystalline $ZnIn_2Se_4$ layers were grown on thoroughly etched semi-insulating GaAs(100) substrate at $400^{\circ}C$ with hot wall epitaxy (HWE) system by evaporating, $ZnIn_2Se_4$ source at $630^{\circ}C$. After the as-grown $ZnIn_2Se_4$ single crystalline thin films was annealed in Zn-, Se-, and In-atmospheres, the origin of point defects of $ZnIn_2Se_4$single crystalline thin films has been investigated by the photoluminescence(PL) at 10 K The native defects of $V_{Zn}$, $V_{Se}$, $Zn_{int}$ and $Se_{int}$ obtained by PL measurements were classified as a donors or acceptors type. And we concluded that the heat-treatment in the Se-atmosphere converted $ZnIn_2Se_4$ single crystalline thin films to an optical p-type. Also, we confirmed that In in $ZnIn_2Se_4$/GaAs did not form the native defects because In in $ZnIn_2Se_4$ single crystalline thin films existed in the form of stable bonds.

• Applied Chemistry for Engineering
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• v.22 no.3
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• pp.328-331
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• 2011

ZnSe quantum dots (QDs) were prepared by employing water-containing Dioctyl sodium sulfosuccinate (AOT) reversed micelles (microemulsions) and the silica-encapsulated ZnSe QDs were obtained by a direct injection of tetraethyl orthosilicate (TEOS) into the microemulsion system. When the QDs were coated by silica, well-defined spherical shapes were formed and the average size of the QDs was near 7 nm. In addition, the photoluminescence (PL) efficiency of the QDs was reduced from 8.0 to 1.1% as they were encapsulated by silica. However, the solid layers of the silica-encapsulated ZnSe QDs on gold surfaces showed the excellent photostability. In particular, they are cadmium free and thus, less toxic. Moreover, the present method does not require a hot reaction temperature or extremely toxic H2Se gas as a Se precursor. Accordingly, the method can be a safer and more economical process for producing silica-encapsulated ZnSe QDs, which may be a potential media for biosensors.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.8 no.2
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• pp.263-268
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• 1998

(100) ZnSe crystals with twin and grain free were grown by vapor transport method. The defect in (100) ZnSe crystals was investigated by FWHM of X-ray Rocking Curve. The growth rate and seed quality are the main parameters of the growth process to obtain the high quality ZnSe crystals. The geometric shape of the grown (100) ZnSe crystal is dependent on the shape of seed, isothermal line in furnace and the growth rate of each surface in crystal.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.50 no.9
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• pp.434-437
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• 2001

ZnSe, ZnSe:Ho/sup 3+/, Mg/sub x/Zn/sub 1-x/Se and Mg/sub x/Zn/sub 1-x/Se:Ho/sup 3+/ crystals were grown by the chemical transport reaction method. The crystal structures and optical energy band gaps of the single crystals were investigated. Their photoluminescence(PL) spectra were measured at 10 [K]. Sharp emission peaks in the blue-green wavelength range and broad emission peaks in the yellow-red wavelength range were observed. The single crystals doped with 1.0 [mol%] of holmium did not show the sharp emission peaks because of defects which were thought to be originated to the holmium dopant.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.03a
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• pp.84-84
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• 2003

The ZnSe epilayers were grown on the GaAs substrate by hot wall epitaxy. After the ZnSe epilayers treated in the vacuum-, Zn-, and Se-atmosphere, respectively, the defects of the epilayer were investigated by means of the low-temperature photoluminescence measurement. The dominant peaks at 2.7988 eV and 2.7937 eV obtained from the PL spectrum of the as-grown ZnSe epilayer were found to be consistent with the upper and the lower polariton peak of the exciton, I$_2$ (D$^{\circ}$, X), bounded to the neutral donor associated with the Se-vacancy. This donor-impurity binding energy was calculated to be 25.3meV The exciton peak, lid, at 2.7812 eV was confirmed to be bound to the neutral acceptor corresponded with the Zn-vacancy. The I$_1$$\^$d/ peak was dominantly observed in the ZnSe/GaAs:Se epilayer treated in the Se-atmosphere. This Se-atmosphere treatment may convert the ZnSe/GaAs:Se epilayer into the p-type. The SA peak was found to be related to a complex donor like a (V$\sub$se/ - V$\sub$zn/) - V$\sub$zn-/

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.13 no.3
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• pp.105-110
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• 2003

The ZnSe epilayers were grown on the GaAs substrate by hot wall epitaxy. After the ZnSe epilayers treated in the vacuum-, Zn-, and Se-atmosphere, respectively, the defects of the epilayer were investigated by means of the low-temperature photoluminescence measurement. The dominant peaks at 2.7988 eV and 2.7937 eV obtained from the PL spectrum of the as-grown ZnSe epilayer were found to be consistent with the upper and the lower polariton peak of the exciton, $I_{2}$ ($D^{\circ}$, X), bounded to the neutral donor associated with the Se-vacancy. This donor-impurity binding energy was calculated to be 25.3 meV, The exciton peak, $I_{1}^{d}$ at 2.7812 eV was confirmed to be bound to the neutral acceptor corresponded with the Zn-vacancy. The $I_{1}^{d}$ peak was dominantly observed in the ZnSe/GaAs : Se epilayer treated in the Se-atmosphere. This Se-atmosphere treatment may convert the ZnSe/GaAs : Se epilayer into the p-type. The SA peak was found to be related to a complex donor like a $(V_{se}-V_{zn})-V_{zn}$.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.11a
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• pp.120-123
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• 2003

The ZnSe epilayers were grown on the GaAs substrate by hot wall epitaxy. After the ZnSe epilayers treated in the vacuum-, Zn-, and Se-atmosphere, respectively, the defects of the epilayer were investigated by means of the low-temperature photoluminescence measurement. The dominant peaks at 2.7988 eV and 2.7937 eV obtained from the PL spectrum of the as-grown ZnSe epilayer were found to be consistent with the upper and the lower polariton peak of the exciton, $I_2$ ($D^{\circ}$, X), bounded to the neutral donor associated with the Se-vacancy. This donor-impurity binding energy was calculated to be 25.3 meV. The exciton peak, $I_1^d$, at 2.7812 eV was confirmed to be bound to the neutral acceptor corresponded with the Zn-vacancy. The $I_1^d$ peak was dominantly observed in the ZnSe/GaAs:Se epilayer treated in the Se-atmosphere. This Se-atmosphere treatment may convert the ZnSe/GaAs:Se epilayer into the p-type. The SA peak was found to be related to a complex donor like a $(V_{Se}-V_{Zn})-V_{Zn}$.