In the present contribution, we have measured and simulated room temperature bias- and frequency-dependent capacitances of thin-film solar cell devices. The results of both the simulations and experimental measurements are represented as 2-D contour plots showing the derivative of the capacitance with respect to the frequency multiplied by the frequency. These plots are called “loss maps,” because responses in these contour plots correspond to responses of different nonidealities in the devices. Using a 1-D drift-diffusion solver (SCAPS), we have simulated the responses of different nonidealities of the solar cell devices, such as series resistance, bulk defects, interface defects, back contact barrier, and absorber–buffer barrier. We have shown that some nonidealities have a quite recognizable trace in the loss map. Other nonidealities on the other hand show responses that look quite similar in the bias voltage and frequency space, making exact conclusions on the nature and position of the defect responses in thin-film solar cells most of the times difficult. We have compared the simulated results with experimental measurements of one of our Cu(In,Ga)Se2 (CIGS) solar cell devices and came to the conclusion that there is likely a bulk defect or a spike-like barrier at the CIGS–CdS interface present in our particular device. The loss map can, in some cases, be useful in order to analyze admittance spectroscopy data in a graphical and relatively intuitive way.

中文翻译：

---

薄膜太阳能电池的偏置相关导纳光谱：实验和模拟

在目前的贡献中，我们测量并模拟了薄膜太阳能电池器件的室温偏置和频率相关电容。模拟和实验测量的结果都表示为二维等高线图，显示了电容相对于频率乘以频率的导数。这些图被称为“损失图”，因为这些等高线图中的响应对应于设备中不同非理想性的响应。使用一维漂移扩散求解器 (SCAPS)，我们模拟了太阳能电池器件的不同非理想性的响应，例如串联电阻、体缺陷、界面缺陷、背接触势垒和吸收体-缓冲势垒。我们已经证明了一些非理想在损失图中具有相当可识别的痕迹。另一方面，其他非理想性显示在偏置电压和频率空间中看起来非常相似的响应，在大多数情况下很难对薄膜太阳能电池中的缺陷响应的性质和位置做出准确的结论。我们将模拟结果与我们的其中一个 Cu(In,Ga)Se2 (CIGS) 太阳能电池器件的实验测量值进行了比较，得出的结论是 CIGS-CdS 界面可能存在体缺陷或尖峰状势垒存在于我们的特定设备中。在某些情况下，损耗图可用于以图形和相对直观的方式分析导纳光谱数据。大多数时候很难对薄膜太阳能电池中缺陷响应的性质和位置做出准确的结论。我们将模拟结果与我们的其中一个 Cu(In,Ga)Se2 (CIGS) 太阳能电池器件的实验测量值进行了比较，得出的结论是 CIGS-CdS 界面可能存在体缺陷或尖峰状势垒存在于我们的特定设备中。在某些情况下，损耗图可用于以图形和相对直观的方式分析导纳光谱数据。大多数时候很难对薄膜太阳能电池中缺陷响应的性质和位置做出准确的结论。我们将模拟结果与我们的其中一个 Cu(In,Ga)Se2 (CIGS) 太阳能电池器件的实验测量值进行了比较，得出的结论是 CIGS-CdS 界面可能存在体缺陷或尖峰状势垒存在于我们的特定设备中。在某些情况下，损耗图可用于以图形和相对直观的方式分析导纳光谱数据。