掺铒a-Si∶H,O薄膜1.54μm光致发光和微结构

国家自然科学基金,国家攀登计划

铒、氧共注a-Si:H和a-SiCx:H的1.54μm光致发光

在a-Si:H和a-SiCx:H中共注稀土铒和氧。300 ℃和400 ℃热退火后,测得了来自发光中心Er~(3+)内层4f电子跃迁的1.54 μm光致发光。400 ℃是较好的退火温度。随着碳含量的增加,发光强度逐渐减弱,这可能是由于碳的引入减弱了间隙氧退火时的迁移能力所致。

Er离子在Inp、GaAs和Si中的1.54μm特征发光峰

分别在InP、GaAs和Si中以7×10＜′14＞和1×10＜′15＞cm＜′－2＞的剂量进行Er离子注入, 并采用闭管、快速和炉退火等热处理。低温光致发光（PL）、反射式高等电子衍射和卢瑟福背散射实验研究表明, 上述样品中Er＜′3＋＞离子特征发光的中心波长均出现在1．5μm处, 其中InP的发光峰最强, 而注入损伤的恢复是影响Er＜′3＋＞发光的重要因素之一。卢瑟福背散射分析进一步证实退火后Er原子在Si中向表面迁移, 而在InP中的外扩散较小, 并比较了Er在InP和Si晶格中的占位情况。图7参12

Elemental carbon record of paleofire history on the Chinese Loess Plateau during the last 420 ka and its response to environmental and climate changes

IEECAS SKLLQG

关中平原420―350kaBP的古土壤与环境

IEECAS SKLLQG

1.54 mu m near-infrared photoluminescent and electroluminescent properties of a new Erbium (111) organic complex

The crystal structure of Er(PM)(3)(TP)(2) [PM = 1-Phenyl-3-methyl-4-isobutyryl-5-pyrazoloiie, TP = triphenyl phosphine oxide] was reported and its photoluminescence properties were studied by UV-vis absorption, excited, and emission spectra. The Judd-ofelt theory was introduced to calculate the radiative transition rate and the radiative decay time of 3.65 ms for the I-4(13/2) -> I-4(15/2) transition of Er3+ ion in this complex.

1.54 mu m infrared photoluminescence and electroluminescence from an erbium organic compound

Infrared emission at 1.54 mu m excited optically and electrically from an erbium organic compound tris(acetylacetonato)(1,10-phenanthroline) erbium [Er(acac)(3)(phen)] is observed. The rare-earth complex is dispersed into a polymer matrix of poly(N-vinylcarbazole) (PVK) to fabricate an electroluminescent (EL) device with an ITO/PVK:Er(acac)(3)(phen)/Al:Li/Ag structure, where ITO represents indium-tin-oxide-coated glass. The device shows infrared EL emission at 1.54 mu m, which suggests a simple and cheap method to obtain a light source for 1.54-mu m-wavelength devices in optical communications. (C) 2000 American Institute of Physics. [S0021-8979(00)00301-7].

Elemental carbon record of paleofire history on the Chinese Loess Plateau during the last 420 ka and its response to environmental and climate changes

An elemental carbon (EC) record, covering the last 420 ka, was reconstructed using chemical oxidation method on a loess and paleosol sequence from the Lingtai section on the Chinese Loess Plateau. The EC record reveals the paleofire history and its relationship with climate and vegetation changes on the Chinese Loess Plateau. Our results show that the EC abundance is generally higher in the paleosols than in the loess layers, showing a glacial/interglacial pattern, which is coincident with biomass changes. This variation pattern indicates that paleofires were intensified when biomass accumulated and climate changed abruptly especially from wet to dry conditions. The EC abundance increases sharply at similar to 130 kaB.P., indicating a dramatic change in the vegetation and climate variation patterns. The occurrence of a peak value with the highest average EC abundance in the Holocene may reflect the occurrence of a major climate event at similar to 6 kaB.P., and may also be partly due to more frequent anthropogenic fire usages. (c) 2007 Elsevier B.V. All rights reserved.