Low-Temperature Processed Electron Collection Layers of Graphene/TiO₂ Nanocomposites in Thin Film Perovskite Solar Cells

Abstract

The highest efficiencies in solution-processable perovskite-based solar cells have been achieved using an electron collection layer that requires sintering at 500 °C. This is unfavorable for low-cost production, applications on plastic substrates, and multijunction device architectures. Here we report a low-cost, solution-based deposition procedure utilizing nanocomposites of graphene and TiO 2 nanoparticles as the electron collection layers in meso-superstructured perovskite solar cells. The graphene nanoflakes provide superior charge-collection in the nanocomposites, enabling the entire device to be fabricated at temperatures no higher than 150 °C. These solar cells show remarkable photovoltaic performance with a power conversion efficiency up to 15.6%. This work demonstrates that graphene/metal oxide nanocomposites have the potential to contribute significantly toward the development of low-cost solar cells.

Graphene based metal and metal oxide nanocomposites: synthesis, properties and their applications

“…432 Significant work has been done on HRG/TiO 2 , where the photocatalytic activities of TiO 2 NPs have been reported to be enhanced by the inclusion of graphene. 433,434 437 The NPs exhibited a tetragonal cuboid-morphology with square crystal facets and a side length ranging from 250 to 300 nm, and they were enclosed by the {001} and {100} crystal facets (cf. Fig.…”

Carbon Nanotubes in TiO2 Nanofiber Photoelectrodes for High‐Performance Perovskite Solar Cells

“…On the other hand, the incorporation of highly conductive carbon nanomaterials such as graphene and carbon nanotubes (CNTs) has also been proven to be an effective method to facilitate the charge transport and extend the electron lifetime, thereby enhancing the efficiency of PV devices 22, 34, 35, 36, 37. Although graphene and its derivatives have been successfully utilized for improving the performance of PSCs,38, 39, 40, 41, 42, 43 there has been no effort in the application of CNTs for use in PSC photoelectrodes. It should be noted that due to their unique structure and outstanding properties including excellent conductivity and high optical transparency, CNTs have exhibited promising results when they are used as an HTM and cathode in PSCs 44, 45, 46, 47, 48, 49.…”

Effects of Cl Addition to Sb-Doped Perovskite-Type CH3NH3PbI3 Photovoltaic Devices

“…Since a conversion efficiency reached 15% [8], higher efficiencies have been achieved for various device structures and processes [9][10][11][12], and the photoconversion efficiency increased up to ca. 20% [13][14][15].…”