Encapsulates are, in general, the passive components of any photovoltaic device that provides the required shielding from the externally stimulated degradation. Here we provide comprehensive physical insight depicting a rather non-trivial active nature, in contrast to the supposedly passive, atomic layer deposition (ALD) grown Al2O3 encapsulate layer on the hybrid perovskite [(FA0.83MA0.17)0.95Cs0.05PbI2.5Br0.5] photovoltaic device having the configuration: glass/FTO/SnO2/perovskite/spiro-OMeTAD/Au/(±) Al2O3. By combining various electrical characterization techniques, our experimental observations indicate that the ALD chemistry produces considerable enhancement of the electronic conductivity of the spiro-OMeTAD hole transport medium (HTM), resulting in electronic modification of the perovskite/HTM interface. Subsequently, the modified interface provides better hole extraction and lesser ionic accumulation at the interface, resulting in a significant lowering of the burn-in decay and nearly unchanged charge transport parameters explicitly under the course of continuous operation. Unlike the unencapsulated device, the modified electronic structure in the Al2O3 coated device is essentially the principal reason for better performance stability. Data presented in this communication suggest that the ionic accumulation at the spiro-OMeTAD/perovskite interface triggers the device degradation in the uncoated devices, which is eventually followed by material degradation, which can be avoided by active encapsulation.

中文翻译：

---

通过主动封装钙钛矿太阳能电池进行界面改性，提高操作稳定性

封装通常是任何光伏设备的无源组件，可提供所需的屏蔽以防止外部刺激退化。在这里，我们提供了全面的物理洞察，描绘了一个相当重要的主动性质，与杂化钙钛矿 [(FA0.83MA0.17)0.95Cs0.05PbI2.5Br0 上所谓的被动原子层沉积 (ALD) 生长的 Al2O3 封装层形成对比.5] 具有以下配置的光伏器件：玻璃/FTO/SnO2/钙钛矿/spiro-OMeTAD/Au/(±) Al2O3。通过结合各种电学表征技术，我们的实验观察表明，ALD 化学显着增强了螺-OMeTAD 空穴传输介质（HTM）的电子电导率，从而导致钙钛矿/HTM 界面的电子改性。随后，改进的界面提供了更好的空穴提取和更少的界面离子积累，从而在连续操作过程中显着降低了老化衰减和几乎不变的电荷传输参数。与未封装的器件不同，Al2O3 涂层器件中改进的电子结构本质上是性能稳定性更好的主要原因。该通讯中提供的数据表明，螺-OMeTAD/钙钛矿界面处的离子积累引发了未涂层器件中的器件退化，最终导致材料退化，而这可以通过主动封装来避免。导致在连续操作过程中显着降低老化衰减和几乎不变的电荷传输参数。与未封装的器件不同，Al2O3 涂层器件中改进的电子结构本质上是性能稳定性更好的主要原因。该通讯中提供的数据表明，螺-OMeTAD/钙钛矿界面处的离子积累引发了未涂层器件中的器件退化，最终导致材料退化，而这可以通过主动封装来避免。导致在连续操作过程中显着降低老化衰减和几乎不变的电荷传输参数。与未封装的器件不同，Al2O3 涂层器件中改进的电子结构本质上是性能稳定性更好的主要原因。该通讯中提供的数据表明，螺-OMeTAD/钙钛矿界面处的离子积累引发了未涂层器件中的器件退化，最终导致材料退化，而这可以通过主动封装来避免。