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Photoluminescence and chemical properties of ZnS:Mn2+ nanocrystal powder synthesized in the AOT reverse micelles modified with lauryl phosphate

“…2. These optimum excitation wavelengths are shorter than that of bulk, 350 nm [2]. This indicates that the quantum confinement is still remained in the powder, although a part of AOT and HLP surfactants could be removed to cause the direct contact among nanocrystals after drying colloidal solution and hence the quantum confinement is weaker in the powder than that in the colloidal solution.…”

“…acrylic acid and methacrylic acid), poly(carboxyl acids), poly(vinyl alcohol), sodium polyphosphate, mercaptoethanol, etc. In particular, the PL intensity of the ZnS:Mn 2+ nanocrystal remarkably increases using a capping agent with a carboxyl group [1][2][3][4]. The reverse micelle method [5][6][7][8] and the synthesis of tri-n-octylphosphine oxide (TOPO) capped semiconductors [9] are also used for the formation of ZnS:Mn 2+ nanocrystal with a transparent insulating silica layer or in a silica matrix is prepared by sol-gel, co-precipitation and reverse micelle methods [10][11][12][13][14][15][16].…”

“…No difference in the decay times between the nanocrystal and the bulk of ZnS:Mn 2+ is recognized from the time-resolved spectra [17,18]. The details of the mechanism on the PL enhancement of ZnS:Mn 2+ nanocrystals have been investigated from several aspects of the temperature dependence of the PL intensity [19] and the local structural analysis of Mn 2+ by electron paramagnetic resonance (EPR) spectroscopy [2,[20][21][22][23].…”

“…In our previous work, modification of ZnS:Mn 2+ nanocrystal colloidal solution by a surfactant with a phosphate group or a carboxyl group increases the PL intensity and its quantum efficiency corresponding to the d-d transition of Mn 2+ ions through energy transfer by exciting the interband of ZnS [1,2,5,29,30]. We prepared the ZnS:Mn 2+ nanocrystal in AOT reverse micelles modified by lauryl phosphate (HLP), and measured the solidstate 31 P NMR spectrum by 1 H → 31 P cross-polarization (CP) in a magnetic field of 7.05 T at the magic angle spinning rate of 3.5 kHz [10].…”

Studies on the synthesis of europium activated yttrium oxide by wet-chemical method

“…Europium activated yttrium oxide (Y 2 O 3 :Eu 3+ ) is a well-known red emitting phosphor used in lightening industry and optoelectronic devices (PDP, LED, CRT, FED) [3][4][5]. For this applications, characteristics of Y 2 O 3 :Eu powder such as luminescence efficiency, particle morphology and size or crystallinity are of utmost importance [6,7].…”