Highly Efficient Large-Area Flexible Perovskite Solar Cells Containing Tin Oxide Vertical Nanopillars without Oxygen Vacancies

Abstract

Fabrication of high-quality electron transporting layers (ETLs) on large-area flexible electrodes is necessarily required, but challenging, to improve photovoltaic performance of flexible perovskite solar cells (PSCs) that are demanded for wearable electronic devices. This work shows one-step, oxygen-assisted glancing angle deposition to facilely deposit polycrystalline SnO2 nanopillars (NPs) that are free of oxygen deficiencies and vertically protrude on large-area transparent electrodes. Functioning as ETLs, SnO2 NPs comprehensively lead to an enhancement of light harvesting in perovskites, exciton separation, electron extraction and collection, and hole blocking, as well as the prevention of perovskite decomposition and the formation of perovskite defects. Large-area (1 cm2) flexible PSCs containing the SnO2 NPs show the champion power conversion efficiency (PCE) of 14.9%, which undergoes only 10% degradation for approximately 800 h storage and 20% degradation by manual bending for around 400 times. These photovoltaic performances are remarkably superior to large-area flexible PSCs having the conventionally used spin-coated SnO2 thin films that contain oxygen vacancies. These results pave the way toward scale-up fabrication of flexible PSCs that simultaneously satisfy the commercial requirements of high photovoltaic efficiency, shelf stability, and mechanical stability.

Highly Efficient and Stable Perovskite Solar Cells Incorporating Chlorinated-Tin Oxide Electron Transport Layers Prepared via Coordination of Diacyl-Metal Cations

“…The electronic structure of the SnO 2 surfaces is correlated to the density of oxygen vacancies. As the vacancies are filled with heterogeneous molecules or atoms, a downward shift in the energy levels was observed. , Ultraviolet photoelectron spectroscopy (UPS) analysis was used to calculate the Fermi level ( E F ), conduction band minimum (CBM), and valence band maximum (VBM) of the pristine and AC/SnO 2 ETLs. In the high-binding-energy regime, the binding-energy cutoff ( E cutoff ) decreased from 16.84 to 16.74 eV as the AC concentration increased from 0 to 4.2 mM (Figure A).…”

Robust electron transport layers of SnO2 for efficient perovskite solar cells: recent advances and perspectives

“…3i). 98 The film deposition is uniform over an area of 1 cm 2 . The SnO 2 NPs without oxygen vacancies significantly improved the photovoltaic performance of large-area flexible PSCs compared to that of spin-coated SnO 2 films with V O .…”

“…(i) Oxygen-assisted glancing angle deposition. Reproduced with permission 98. Copyright 2022, American Chemical Society.…”

Insights and potentials of two-dimensional black phosphorous-based solar cells

“…Nanostructured materials with morphology of nanowires and nanotubes attract researchers to harvest solar energy. Nano brushes, vertical nanopillars, funnellike structures, straight nano wires, nano porous films and nano islands have been reported to harvest solar energy more efficiently [1][2][3][4]. Black-Phosphorus exhibit superior optoelectronic properties than the other two-dimensional materials such as graphene and molybdenum dioxide.…”