Efficient and Stable Nonfullerene‐Graded Heterojunction Inverted Perovskite Solar Cells with Inorganic Ga₂O₃ Tunneling Protective Nanolayer

Abstract

Inverted planar perovskite solar cells (PSCs) exhibit advantages in terms of simple device fabrication, good reproducibility, and less hysteresis. However, there still remain challenges to passivate the trap states within the perovskite film and reduce interface instability arising from penetration of moisture and the diffusion of metal electrode. In this work, perovskite passivation is reported using gradiently distributed nonfullerene electron-rich Lewis bases small molecule IDIC (a π-conjugated Lewis base: indacenodithiophene endcapped with 1.1-dicyanomethylene-3-indanone), which is realized through an antisolvent dropping process. Additionally, an inorganic wide band gap Ga 2 O 3 is introduced as a tunneling nanolayer into interface between the metal electrode and electron transport layer that effectively passivate interface and mitigate moisture and metal ion diffusion. These treatments enable the fabrication of CH 3 NH 3 PbI 3 -based inverted PSCs with excellent power conversion efficiencies up to 19.86% as well as enhanced ambient stability. This work provides new strategies to improve the performance and stability for the inverted PSCs.

Ultrasensitive, Superhigh Signal-to-Noise Ratio, Self-Powered Solar-Blind Photodetector Based on n-Ga2O3/p-CuSCN Core–Shell Microwire Heterojunction

“…The cutoff wavelength of Ga 2 O 3 is observed at approximately 255 nm, corresponding to an optical direct band gap ( E g ) of 4.87 eV as shown in the inset. The optical absorption spectrum of the CuSCN film demonstrates a direct band gap of 3.88 eV and obvious absorption peaks at 303 and 240 nm, in good agreement with previously reported data. ,− In general, the valence band maximum levels of CuSCN and Ga 2 O 3 can be calculated to be 5.40 and 7.95 eV below the vacuum level, respectively. , Taking E g into account, the conduction band minimum levels are deduced to be 1.52 eV for CuSCN and 3.08 eV for Ga 2 O 3 . Therefore, a typical type II heterojunction could be formed at the interface by the contact of Ga 2 O 3 and CuSCN.…”

Efficient Perovskite Solar Cells with a Novel Aggregation‐Induced Emission Molecule as Hole‐Transport Material

“…It has been earlier reported that the trap states/defects in perovskite films can be effectively reduced by introducing cyano‐based small molecules either in perovskite precursor or as interfacial layers . Therefore, a possible mechanism of the suppressed nonradiative recombination in the perovskite film on TFM is the passivation of the unsaturated Pb at TFM perovskite interfaces by CN − due to forming of Pb–N bonds, which results in the suppression of trap states at perovskite/TFM interface (Figure a).…”

Liquid Metal Amplified Charge Separation in Photocatalytic Micro/Nanomotors for Antibacterial Therapy

“…Additionally, compared to the Ga 3d spectrum of Ga LM, GaGCN exhibited a new peak at 19.5 eV corresponding to the Ga−N bond and a significantly enhanced Ga−O peak at 20.4 eV, 44 indicating that Ga LM underwent further oxidation and formed a g-C 3 N 4 −Ga 2 O 3 composite shell on the surface of GaGCN micro/nanoparticles. The formation of the g-C 3 N 4 −Ga 2 O 3 composite shell is crucial as it not only preserves the spherical shape of the GaGCN particles to prevent uncontrolled agglomeration but also facilitates charge transfer and separation between the Pt layer, g-C 3 N 4 , and LM core via tunneling effects, 45 which are essential for achieving self-electrophoresis and photocatalytic motion control.…”