Improved Up-Conversion Luminescence from Er3+:LaF3 Nanocrystals Embedded in Oxyfluoride Glass Ceramics via Simultaneous Triwavelength Excitation
Improved Up-Conversion Luminescence from Er3+:LaF3 Nanocrystals Embedded in Oxyfluoride Glass Ceramics via Simultaneous Triwavelength Excitation
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DOI：
10.1021/acs.jpcc.5b08103
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发表时间：
2015-10-22
影响因子：
3.7
通讯作者：
Qiu, Jianrong
中科院分区：
文献类型：
--
作者：
Chen, Zhi;Wu, Guobo;Qiu, Jianrong
上转换（UC），收获近红外（NIR）太阳光，是非常需要的光伏（PV）电池。关于这一概念，大多数报道的UC材料及其应用的实验，然而，传统的研究是在单色激光与窄激发带，这是难以满足太阳光谱转换的要求。鉴于在光伏电池中的实际应用，研究UC材料在同时多波长甚至宽带近红外（NIR）太阳光激发下的作用更有意义。本文研究了含LaF 3：Er 3+纳米晶的锗氧氟玻璃陶瓷（GCs）在同时三波长激发下的UC发光特性。同时三波长激发时的UC发射强度与单色激发的情况相比大大增强。UC发光机制进行了深入解释的协同UC效应，由于在不同的激发波长建立的激发态的扰动。我们展示了应用程序的同时三波长激发的GC添加到薄膜氢化非晶硅（a-Si：H）太阳能电池的背面。由反射UC光同时三波长激发时产生的光敏电流显着增强的情况下，在单色激发。这种Er 3+掺杂的锗酸氟氧化物GC通过同时多波长激发来收集更广泛的NIR太阳光光子，在不久的将来具有巨大的潜力来提高PV电池的功率转换效率。
Up-conversion (UC), harvesting near-infrared (NIR) sunlight, is highly desirable for photovoltaic (PV) cells. In regard to this concept, most of the reported experiments on UC materials and their applications, however, were conventionally studied on a monochromatic laser with a narrow excitation band, which is difficult to meet the requirement of solar spectrum conversion. Given the practical applications in PV cells, investigations for UC materials upon simultaneous multiwavelengths even broadband near-infrared (NIR) sunlight excitation are much more meaningful. Herein, we studied the UC luminescence properties of germanate oxyfluoride glass ceramics (GCs) containing LaF3:Er3+ nanocrystals with lower phonon energy upon simultaneous triwavelength excitation. The UC emission intensities upon simultaneous triwavelength excitation were drastically enhanced in comparison with the case of that by monochromatic excitation. The UC luminescence mechanisms were interpreted in-depth in terms of synergetic UC effect owing to the perturbation in the excited states established by different excitation wavelengths. We demonstrated the application of the simultaneous triwavelength excited GC by adding it to the rear face of thin-film hydrogenated amorphous silicon (a-Si:H) solar cells. The photoactive current generated by the reflected UC light upon simultaneous triwavelength excitation was dramatically enhanced in contrast to the case of that upon monochromatic excitation. This Er3+-doped germanate oxyfluoride GC, harvesting broader NIR sunlight photons via simultaneous multiwavelength excitation, has colossal potential to improve the power conversion efficiency in PV cells in the near future.