Bismuth-doped oxide glasses as potential solar spectral converters and concentrators
Bismuth-doped oxide glasses as potential solar spectral converters and concentrators
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DOI：
10.1039/b812316k
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发表时间：
2009-01-01
影响因子：
--
通讯作者：
Wondraczek, Lothar
中科院分区：
文献类型：
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作者：
Peng, Mingying;Wondraczek, Lothar
光伏电池（或电池材料）的电子特性、带隙和反射率与太阳光的光谱分布不充分匹配，往往限制了光伏电池能量转换过程的效率。在这种情况下，太阳能光谱转换器和聚光器依赖于使用发光材料来转换或重新定向入射的阳光，目前正在重新受到关注。在这项研究中，各种铋掺杂氧化物玻璃被考虑用于这些应用。结果表明，这种玻璃在来自铋基发射中心的弱紫外-可见光激发下，在近红外光谱范围（NIR）表现出较宽的发光。在蓝绿色中有很强的吸收，但在波长大于800nm的波长上有很高的透射率，这是高效发光集中器的先决条件，光学均匀性和太阳热稳定性为潜在的替代品提供了重要的优势。研究表明，所考虑的玻璃与低带隙半导体（如GaSb、Ge或InAs）结合在一起特别有趣。使用双掺杂玻璃作为UV-VIS ->近红外下转换器，不仅可以显著延长此类电池的工作窗口，而且可以大大提高其在太阳或热辐射下的整体效率。
The efficiency of photovoltaic energy conversion processes is often limited by the fact that electronic properties, band-gap and reflectivity of the employed cell ( or cell material) and the spectral distribution of sunlight do not sufficiently match. In this context, solar spectral converters and concentrators that rely on the use of luminescent materials to either convert or redirect incoming sunlight are presently receiving renewed interest. In this study, various bismuth-doped oxide glasses were considered for these applications. It is shown that such glasses exhibit broad luminescence in the near infrared spectral range ( NIR) upon excitation with soft ultraviolet to visible light ( UV-VIS), originating from Bi-based emission centers. Strong absorption in the blue-green but high transmission at wavelengths larger than similar to 800 nm as prerequisite for efficient luminescence concentrators, and optical homogeneity and solar-thermal stability provide important advantages over potential alternatives. It is demonstrated that the considered glasses are particularly interesting in combination with low-bandgap semiconductors, e.g. GaSb, Ge or InAs. Using Bi-doped glasses as UV-VIS -> NIR down-converters would not only lead to significant extension of the operation window of such cells, but also strongly improve their overall efficiency under solar or thermal irradiation.