CELLO measurement technique for local identification and characterization of various types of solar cell defects
CELLO measurement technique for local identification and characterization of various types of solar cell defects
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用于局部识别和表征各种类型太阳能电池缺陷的 CELLO 测量技术
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发表时间：
2011
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影响因子：
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通讯作者：
H. Föll
中科院分区：
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作者：
J. Carstensen;A. Schütt;G. Popkirov;H. Föll
CELO技术允许测量大量太阳能电池参数的本地数据，如体寿命、背面复合速度、扩散系数和串联电阻。这些参数的不均匀导致了正向的横向流动，这混合了不同类型缺陷的影响。即使所有的局部参数都是已知的，也需要一个完整的模拟来获得关于局部效率的信息。例如，在太阳能电池工作时或在开路时的直接细胞测量允许直接提取该组合信息。在这篇文章中，我们将举几个例子，说明多晶硅太阳能电池的各种缺陷类型。
主要是为了节省测量时间，将多个频率同时施加作为激光强度扰动信号，并进行FFT反卷积分析。这些频率可以同时应用于三个不同波长的共焦激光器，即穿透深度。通常同时分析4个频率，以保持良好的信噪比。我们也将很快讨论这一特性。特别是，深度穿透激光的应用显著提高了拟合过程的稳健性，并允许可靠地分离块体和表面复合以及迁移率依赖关系(©2011 Wiley-VCH Verlag GmbH&Co.KGaA，Weinheim)
The CELLO technique allows to measure local data for a large number of solar cell parameters like bulk life time, back side surface recombination velocity, diffusion coefficient, and serial resistance. Inhomogeneities of these parameters induce lateral current flow in forward direction, which mixes the effects of the different defect types. Even if all local parameters would be known, a complete simulation is needed to obtain information about the local efficiency. Direct CELLO measurement at e.g. the working of the solar cell or at open circuit allows extracting this combined information directly. Examples for this will be presented in this paper, dealing with multicrystalline silicon solar cells showing a variety of defect types.
Mainly to save measurement time several frequencies are applied simultaneously as a Laser intensity perturbation signal and analyzed by FFT deconvolution. The frequencies can be applied simultaneously to 3 confocal Lasers with different wavelength, i.e. penetration depths. Typically 4 frequencies are analyzed simultaneusly in order to maintain a good signal to noise ratio. This features will be discussed shortly as well. Especially the application of a deep penetrating Laser significantly increases the robustness of the fitting procedure and allows to separate reliably bulk and surface recombination and mobility dependencies (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)