Robin Nicholas

Abstract:

In this Letter, we demonstrate a planar n–i–p perovskite solar cell design with a steady-state efficiency of up to 18.8% in the absence of any electronic dopants. In the device stack, solution-processed SnO2 is used as an electron-accepting n-type layer. The absorber layer is a perovskite with both mixed organic A-site cations and mixed halides (FA0.83MA0.17Pb(I0.83Br0.17)3). The hole-transporting p-type layer is a double-layer structure of polymer-wrapped single-walled carbon nanotubes and undoped spiro-OMeTAD. We show that this approach can deliver steady-state efficiencies as high as and even higher than those of traditionally doped spiro-OMeTAD, providing a pathway for dopant-free perovskite solar cells crucial for long-term stability.

Abstract:

The extent to which the soft structural properties of metal halide perovskites affect their optoelectronic properties is unclear. X-ray diffraction and micro-photoluminescence measurements are used to show that there is a coexistence of both tetragonal and orthorhombic phases through the low-temperature phase transition, and that cycling through this transition can lead to structural changes and enhanced optoelectronic properties.

Abstract:

The remarkable optoelectronic properties of metal halide perovskite absorbers have, in the past years, made the perovskite solar cell one of the most promising emerging photovoltaic technologies. The charge collecting layers are essential parts of this type of solar cell. Carbon nanotubes have emerged as a potential candidate to take on this role. Equipped with a range of highly beneficial properties including excellent charge transport characteristics, chemical inertness, as well as mechanical robustness, carbon nanotubes are able to both efficiently extract photogenerated charges, and improve the resilience and stability of a perovskite solar cell. In this Research News article we give a concise overview of the current state-of-the-art of perovskite solar cells in which carbon nanotubes are incorporated as a charge conduction layer.

Abstract:

The extent to which the soft structural properties of metal halide perovskites affect their optoelectronic properties is unclear. X-ray diffraction and micro-photoluminescence measurements are used to show that there is a coexistence of both tetragonal and orthorhombic phases through the low-temperature phase transition, and that cycling through this transition can lead to structural changes and enhanced optoelectronic properties.