Compositional tuning of the perovskite absorber has led to immense improvements in stability and efficiency of perovskite solar cells leading to a certified efficiency of 22.7% for a single-junction laboratory device. The successful transition of a photovoltaic technology from the lab into the field requires, however, two additional important parameters aside from efficiency which are essential for real-world deployment: stability and scalability.
We propose using single-walled carbon nanotubes (SWCNTs) as p-type layer for perovskite solar cells for future applications.
Carbon nanotubes combine several highly attractive characteristics such as chemical inertness and mechanical resilience with intrinsically high charge-carrier mobilities endowing them with a unique potential to be a very stable dopant-free charge-selective contact. Furthermore, the SWCNT deposition techniques for large-scale use, such as spray-coating, are already well-established, opening clear avenues for direct implementation in a real-world industrial setting.
In this study, we demonstrate that employing SWCNTs as hole-transporting material can yield steady-state efficiencies of above 20% for alloyed narrow bandgap perovskites, and of over 7% for wide-bandgap perovskites, illustrating the versatility and excellent performance of SWCNTs as charge-selective contact material.