• Journal of the Korean Ceramic Society
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• v.21 no.3
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• pp.245-252
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• 1984

Willemite phosphor is a good one having excellent luminescence efficiency that it;s emission wavelength is in the range of about 525 nm. The energy band gap of this willemite phosphor is about 4.1 eV. When the ratio of ZnO/SiO is 1.8 and Mncl in used as activator source the phosphor has the value of maximum luminescence efficiency. The characteristic of willemite phosphor is tendency of the dependence of temperature. The willemite which was fired with activator after being synthesized at initial firing without activator shows higher value of luminescence efficiency than willemite which was fired with activator in initial stage, When the concentration of activator is 1-1.5mol% it has its most favorite condition and the value of luminescence efficiency decreases according to increasement of activator concentration.

• Bulletin of the Korean Chemical Society
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• v.23 no.10
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• pp.1470-1472
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• 2002

• Journal of the Semiconductor & Display Technology
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• v.17 no.3
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• pp.10-16
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• 2018

In silicon crystalline PV (Photo Voltaic) industry, PV module or panel electric power is directly related to the companies' profit. Thus, many PV companies have invested and focused on R&D activities to get the higher module power. The main BOM (Bills of Material) on the module consists of PV solar cell, ribbon, EVA (Ethylene-Vinyl Acetate copolymer), glass and back sheet. Based on consistent research efforts on enhancing module power using BOM, there have been increase of around 5 watt per module every year as results. However, there are lack of studies related to enhancing accuracy of measurement. In this study, the enhancing on the metrology is investigated and the improvement shows actually contribution to company's profit. Especially, the measurement issues related to heat and to quasi state of bandgap diagram by EL(Electro Luminescence) are described in this study.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.30 no.1
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• pp.42-47
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• 2017

In this study, the physical and optical properties of $ZnS:Mn^{2+}$ Quantum Dot prepared by wet-process condition with Mn/Zn ratio was valuated. The powder characteristics and optical behavior were investigated through XRD, TEM and Photo spectrometer exicted by various UV light source. We found the main peak of ZnS (111) was shifted by 0.8 degree to low angle position with increasing stirring energy from 200 RPM to 600 RPM, which is thought to be the increase of lattice defects during wet process. The photo luminescence at 600 RPM shows also higher blue intensity which is well correlated with XRD results. With increasing Mn/Zn ratio, the PL intensity become higher and shifed by 8.5nm to right side, by the increment of substitutional $Mn^{2+}$ ions.

• Journal of Powder Materials
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• v.12 no.4 s.51
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• pp.279-283
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• 2005

In this study, the ZnS composite powders for host material in phosphor was synthesized in situ by mechanical alloying. As the mechanical alloying time increases, particle size of ZnS decreases. ZnS powders of $1.85\;\mu{m}$ in a mean size was fabricated by mechanical alloying for 10h. The crystal structures of ZnS powders were investigated by X-ray diffraction and the photo-luminescence properties was evaluated with the optical spectra analyzer. The steady state condition of mechanically alloyed ZnS was obtained as a mean particle size of $2\;\mu{m}$ in 5h milling. The sphalerite and wurtize structures coexist in the ZnS mechanically alloyed for 5h. The ZnS powder mechanically alloyed for 10h grows to the sphalerite structure. And the strong emission peaks of ZnS are observed at 480 nm wave length at the powders of mechanically alloyed for 10h, but the sphalerite and wurtize structures in ZnS coexist and emission peaks are not appeared at the powders of mechanically alloyed for 10h.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.32 no.3
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• pp.196-200
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• 2019

In this study, photoluminescence (PL) analysis was performed to evaluate the optical properties of commercial ZnO substrates. Particular attention was paid to the bound exciton (BX) luminescence, which is usually the strongest emission intensity of commercial substrates. At 15 K, PL analysis revealed that the BX peak due to donor-type impurities (donor-bound-exciton; DX) dominated, while two-electron satellite (TES) emission, donor-accepter pair (DAP) emission, and LO-phonon replica emission were also observed. The impurity concentration of the ZnO substrate was determined to be $10^{15}$ to $10^{16}/cm^3$ by examination of the temperature variation of DAP, while the half width and intensity change of the luminescence revealed that the temperature change of BX can be interpreted almost the same as the analysis of free-exciton emission.

• Preventive Nutrition and Food Science
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• v.5 no.3
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• pp.136-141
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• 2000

The properties of pulsed photostimulated luminescence (PPSL) were measured to use as basis data for the detection of irradiated foodstuffs (34 different foods). Samples were packed in polyethylene bags and irradiated at 1, 5, and 10 kGy with a dose rate of 10 kGy/h. The samples irradiated were introduced in the sample chamber without other preparation and measured PPSL photon counts for 60 and 120 s. The PPSL photo counts of the irradiated samples were higher than the unirradiated, increased with increasing irradiation dose, and showed a good relationship between irradiation doses and photon counts in a multinomial expression. These results suggest that the detection of irradiated foodstuffs was possible by PPSL. Therefore, PPSL can be proposed as the method for the detection of irradiated foodstuffs.

• Proceedings of the Materials Research Society of Korea Conference
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• 1998.08a
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• pp.53.3-53
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• 1998

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.8
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• pp.749-753
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• 2006

The $ZnGa_2O_4$ phosphor thick films were fabricated using a screen printing method on Si(100) substrates at various sintering temperatures. The XRD patterns show that the $ZnGa_2O_4$ thick films have a (311) main peak and a spinel structure with increasing sintering temperatures. The particle sizes of $ZnGa_2O_4$ phosphor were about 100 nm and the thickness of $ZnGa_2O_4$ thick film was $10{\mu}m$. The CL and PL properties of $ZnGa_2O_4$ showed main peak of 420nm and maximum intensity at the sintering temperature of $900^{\circ}C$. These results indicate that $ZnGa_2O_4$ phosphor thick films hold promise for displays such as plasma display panel and field emission display.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2012.03a
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• pp.71-71
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• 2012

To control luminescence emission property, a novel series of strong fluorescent fluorin-boron complexes were synthesized in higher yield. The resulting structural analysis was completed. Small molecules with a built-in fluorine-boron core structural architecture has been attracted considered attention as the key emissive elements due to the their good properties such as bipolar charge transport and high photo efficiency. Thus, new type of fluorine-boron(F-B) complexes are designed and prepared. Changing the substituent position on fluorophore ring provided a deep understanding on the relationship between structure and optical properties.