Highly efficient and stable perovskite solar cells based on E‐beam evaporated SnO2 and rational interface defects passivation

Abstract

Owing to the significant roles in balancing carrier transport, bandgap alignment, and perovskite crystallization, realizing high-quality electron transport layers (ETLs) and their effective electronic contact with the perovskite photoactive layer is crucial for future commercialization of perovskite solar cells (PSCs). Here, a high-quality SnO 2 ETL is firstly deposited at room temperature via the lowcost electron beam evaporation (E-beam) technology to help achieve an impressive PCE of 18.88% for rigid PSCs and a PCE of 15.73% for flexible devices. Then we introduced a novel passivating ligand molecule, 11 Maleimidoundecanoic acids (11MA), to help induce functional defects passivation at the interface of SnO 2 /Perovskite to coordinate with Pb 2+ in perovskite and Sn 4+ in SnO 2 via the functional groups (-C = O, -COOH). As a result, 11MA could help achieve the best PCE of 20.94% with negligible hysteresis for rigid devices. Also, doping 11MA in the perovskite photoactive layer further enhanced the PCE to 22.08% with much improved 2000 hours ambient stabilities. Finally, we fabricated different largearea rigid devices (10, 40, 100, and 600 mm 2 ) toward speeding up the commercialization of PSCs by industrial E-beam technology and rational defects passivation strategies.

Preparation of TiO2/SnO2 Electron Transport Layer for Performance Enhancement of All-Inorganic Perovskite Solar Cells Using Electron Beam Evaporation at Low Temperature

“…The conduction band of electron-beam-evaporated SnO 2 thin films typically ranges from −4.06 eV to −4.21 eV relative to the vacuum, while the valence band levels are between −8.56 eV and −8.12 eV [ 41 , 44 , 45 , 46 ]. In contrast, the TiO 2 prepared via the hydrothermal method has a conduction band around −3.93 eV and a valence band around −7.59 eV, respectively [ 37 ].…”

Rational design of formamidine tin-based perovskite solar cell with 30% potential efficiency via 1-D device simulation

“…It is currently an ideal material to replace TiO 2 . More than ten different methods have been explored to prepare the SnO 2 layer, including the sol–gel method, 30 low-temperature atomic layer deposition (ALD) process, 31 chemical bath deposition (CBD) method, 32 physical vapor deposition (PVD) mothed, 31 electrodeposition process, 33 electron beam evaporation (E-beam) technique, 34 and ball milling technology. Most high-efficiency PSCs based on SnO 2 ETL are fabricated by the low-temperature sol–gel method.…”

Molecular Synergistic Passivation for Efficient Perovskite Solar Cells and Self‐Powered Photodetectors

“…However, a general issue in preparing the SnO x layer by high-energy E-beam processing is the produced amorphous SnO x film, which contains many oxygen defects and will scatter photogenerated carriers and substantially reduce carrier mobility. [29,30] In addition, the photogenerated carrier in the excited state will be caught in the intermediate defect level and resulting in serious nonradiative recombination loss, which will dramatically reduce the photovoltaic performance and stability of devices. [31,32] Therefore, minimizing the nonradiative recombination of the electron transporting layer/perovskite interface is crucial to reduce the efficiency gap between the actual value and the Shockley-Queisser limit.…”

“…However, a general issue in preparing the SnO x layer by high‐energy E‐beam processing is the produced amorphous SnO x film, which contains many oxygen defects and will scatter photogenerated carriers and substantially reduce carrier mobility. [ 29,30 ]…”