Universality of non-Ohmic shunt leakage in thin-film solar cells
Universality of non-Ohmic shunt leakage in thin-film solar cells
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DOI：
10.1063/1.3518509
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发表时间：
2010-12-15
影响因子：
3.2
通讯作者：
Alam, M. A.
中科院分区：
文献类型：
--
作者：
Dongaonkar, S.;Servaites, J. D.;Alam, M. A.
我们比较了三种不同类型的薄膜太阳能电池：氢化非晶硅（a-Si:H） p-i-n电池、有机体异质结（BHJ）电池和Cu(In, Ga)Se-2 （CIGS）电池的暗电流-电压（IV）特性。这三种器件类型在低正向偏压（V <近似于0.4）和反向偏压下都表现出显著的分流漏电流，这是经典的太阳能电池二极管模型无法解释的。这种寄生分流电流表现出非欧姆行为，与传统的恒分流电阻模型相反。我们在这里表明，在所有三种太阳能电池类型中，这种分流泄漏（I-sh）具有以下共同的现象学特征：(a)关于V = 0的电压对称性，(b)非线性（幂律）电压依赖性，以及(c)极弱的温度依赖性。基于此分析，我们提供了一种从测量数据中减去该分流电流分量的简单方法，并讨论了其对暗IV参数提取的影响。我们提出了一个空间电荷限制（SCL）电流模型，用于在一致的框架中捕获分流泄漏的所有这些特征，并讨论了导致这种分流电流机制的寄生路径的可能物理起源。(C) 2010年美国物理研究所。(doi: 10.1063/1.3518509)
We compare the dark current-voltage (IV) characteristics of three different thin-film solar cell types: hydrogenated amorphous silicon (a-Si:H) p-i-n cells, organic bulk heterojunction (BHJ) cells, and Cu(In, Ga)Se-2 (CIGS) cells. All three device types exhibit a significant shunt leakage current at low forward bias (V < similar to 0.4) and reverse bias, which cannot be explained by the classical solar cell diode model. This parasitic shunt current exhibits non-Ohmic behavior, as opposed to the traditional constant shunt resistance model for photovoltaics. We show here that this shunt leakage (I-sh), across all three solar cell types considered, is characterized by the following common phenomenological features: (a) voltage symmetry about V = 0, (b) nonlinear (power law) voltage dependence, and (c) extremely weak temperature dependence. Based on this analysis, we provide a simple method of subtracting this shunt current component from the measured data and discuss its implications on dark IV parameter extraction. We propose a space charge limited (SCL) current model for capturing all these features of the shunt leakage in a consistent framework and discuss possible physical origin of the parasitic paths responsible for this shunt current mechanism. (C) 2010 American Institute of Physics. [doi:10.1063/1.3518509]