Organic solar cells (OSCs) with the conventional configuration usually use polyethylenedioxythiophene:polystyrene sulfonate (PEDOT:PSS) as the hole-transporting layer (HTL); however, its acidity tends to affect the performance and long-term stability of the devices. Therefore, replacing PEDOT:PSS with other more stable HTLs is essential for realizing the practical applications of OSCs. To achieve this goal, a simple and low-cost vanadyl oxalate (VOC₂O₄) is identified as a HTL to facilitate high power conversion efficiencies (PCEs), good stability, and high thickness tolerance to be achieved in OSCs. The VOC₂O₄ thin film can be easily prepared by spin-coating from its aqueous solution onto ITO/glass substrate and thermally annealed at 100 °C to exhibit high transmittance, conductivity, and work function. It can be applied as a robust HTL with wide processing conditions, especially after being heated at 200 °C and treated with UV-ozone (UVO) to afford a very high PCE of 18.94% in OSCs. This value is among the highest PCEs obtained for binary OSCs. In addition, the derived OSCs exhibit high thickness tolerance and better stability than those based on PEDOT:PSS as HTL. These results reveal that VOC₂O₄ is an excellent HTL for OSCs, having great potential for large-area device applications.

中文翻译：

---

简单且低成本的草酸氧钒作为空穴传输层可实现高效有机太阳能电池

传统结构的有机太阳能电池（OSC）通常采用聚乙烯二氧噻吩：聚苯乙烯磺酸（PEDOT：PSS）作为空穴传输层（HTL）；然而，其酸性往往会影响器件的性能和长期稳定性。因此，用其他更稳定的HTL替代PEDOT:PSS对于实现OSC的实际应用至关重要。为了实现这一目标，一种简单且低成本的草酸氧钒（VOC ₂ O ₄）被确定为HTL，以促进OSC实现高功率转换效率（PCE）、良好的稳定性和高厚度公差。VOC ₂ O ₄薄膜可以通过将其水溶液旋涂到ITO/玻璃基板上并在100℃下热退火来容易地制备，以表现出高透射率、电导率和功函数。它可以用作具有广泛加工条件的坚固 HTL，特别是在 200 °C 加热并用紫外线臭氧 (UVO) 处理后，可在 OSC 中提供 18.94% 的极高 PCE。该值是二进制 OSC 获得的最高 PCE 之一。此外，与基于 PEDOT:PSS 作为 HTL 的 OSC 相比，衍生的 OSC 表现出高厚度公差和更好的稳定性。这些结果表明VOC ₂ O ₄是一种优秀的OSCs HTL，在大面积器件应用中具有巨大潜力。