Upconversion quantum yield of Er3+-doped β-NaYE4 and Gd2O2S: The effects of host lattice, Er3+ doping, and excitation spectrum bandwidth
Upconversion quantum yield of Er3+-doped β-NaYE4 and Gd2O2S: The effects of host lattice, Er3+ doping, and excitation spectrum bandwidth
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DOI：
10.1016/j.jlumin.2014.03.047
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发表时间：
2014-09-01
影响因子：
3.6
通讯作者：
Goldschmidt, Jan Christoph
中科院分区：
文献类型：
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作者：
Fischer, Stefan;Martin-Rodriguez, Rosa;Goldschmidt, Jan Christoph
在I-4(11/2)-GT下研究了掺Er3+的β-NaYF4和Gd2O2S的上转换发光；1000 nm附近的I-4(15/2)上转换发光非常适合于激发禁带宽度约为1150 nm的硅太阳电池。测量了这些材料在不同Er3+掺杂水平下的单色和宽带激发下的上转换量子产率(UCQY)。我们观察到UCQY强烈依赖于Er3+掺杂、激发光谱带宽和辐照度。单色激发的最佳样品为Gd2O2S：10%Er3+；宽带激发的最佳样品为β-NaYF4：25%Er3+。对于大于3500 W/m(2)的大单色辐照度，两种主体材料达到相似的外部UCQY。特别是，在4020W/m(2)和4070W/m(2)的辐照下，β-NaYF4：25%Er3+和Gd2O2S：10%Er3+的最佳外(内)UCQY分别为8.6%(12.0%)和8.5%(15.1%)。在宽带激发下，我们发现β-NaYF_4：25%Er~(3+)的外部UCQY比Gd2O_2S：10%Er~(3+)的UCQY大1.71倍，这取决于激发的光谱带宽和辐射强度。因此，β-NaYF4主晶格似乎更有利于宽带激发，例如在太阳能电池应用中，而Gd2O2S主晶格的外部UCQY在低辐照度的单色激发下更大。(C)2014爱思唯尔B.V.保留所有权利。
The upconversion luminescence of beta-NaYF4 and Gd2O2S doped with Er3+ was investigated under I-4(11/2) -> I-4(15/2) upconversion emission around 1000 nm is ideally suited for the excitation of silicon solar cells with a band gap of approximately 1150 nm. The upconversion quantum yields (UCQYs) of these materials were measured under monochromatic and broad-band excitations for different Er3+ doping levels. We observed a strong dependence of the UCQY on the Er3+ doping, the spectral bandwidth of the excitation, and the irradiance. The best performing samples were Gd2O2S: 10% Er3+ for monochromatic excitation and beta-NaYF4: 25% Er3+ for broad-band excitation. Both host materials reach similar external UCQYs for large monochromatic irradiance values above 3500 W/m(2). Particularly, the best external (internal) UCQYs are 8.6% (12.0%) for beta-NaYF4: 25% Er3+ and 8.5% (15.1%) for Gd2O2S: 10% Er3+ at irradiances of 4020 W/m(2) and 4070 W/m(2), respectively. Under broadband excitation we found the external UCQY of beta-NaYF4: 25% Er3+ to be up to 1.71 times larger than that for Gd2O2S: 10% Er3+, depending on the spectral bandwidth and the irradiance of the excitation. Thus, the beta-NaYF4 host lattice seems to be more advantageous for broad-band excitation, as required for instance in solar cell applications, whereas the external UCQY of the Gd2O2S host lattice is larger under monochromatic excitation at low irradiances. (C) 2014 Elsevier B.V. All rights reserved.