Laser-Assisted Ultrafast Fabrication of Crystalline Ta-Doped TiO₂ for High-Humidity-Processed Perovskite Solar Cells

Abstract

A titanium dioxide (TiO 2 ) compact film is a widely used electron transport layer (ETL) for n–i–p planar perovskite solar cells (PSCs). However, TiO 2 sufferers from poor electrical conductivity, leading to high energy loss at the perovskite/ETL/transparent conductive oxide interface. Doping the TiO 2 film with alkali- and transition-metal elements is an effective way to improve its electrical conductivity. The conventional method to prepare these metal-doped TiO 2 films commonly requires time-consuming furnace treatments at 450–600 °C for 30 min to 3 h. Herein, a rapid one-step laser treatment is developed to enable doping of tantalum (Ta) in TiO 2 (Ta-TiO 2 ) and to simultaneously induce the crystallization of TiO 2 films from its amorphous precursor to an anatase phase. The PSCs based on the Ta-TiO 2 films treated with the optimized fiber laser (1070 nm) processing parameters (21 s with a peak processing temperature of 800–850 °C) show enhanced photovoltaic performance in comparison to that of the device fabricated using furnace-treated films at 500 °C for 30 min. The ambient-processed planar PSCs fabricated under high relative humidity (RH) of 50–70% display power conversion efficiencies (PCEs) of 18.34% and 16.04% for devices based on Cs 0.1 FA 0.9 PbI 3 and CH 3 NH 3 PbI 3 absorbers, respectively. These results are due to the improved physical and chemical properties of the Ta-TiO 2 films treated by the optimal laser process in comparison to those for the furnace process. The laser process is rapid, simple, and potentially scalable to produce metal-doped TiO 2 films for efficient PSCs.

Hexamethylphosphoramide-Assisted Structure and Morphology Regulation of a PbI2 Film for Air-Processed Efficient Perovskite Solar Cells via a Two-Step Deposition Method

“…In the past decade, organic–inorganic lead halide perovskite solar cells (PSCs) have drawn global attention and achieved a certified power conversion efficiency (PCE) value of 25.7%. , Along with the commercial and industrial development, a simple and low-cost fabrication approach that is less sensitive to the production environment is demanded. Recent research and our past works have demonstrated that high-performance PSCs can be successfully prepared in an ambient environment without a controlled inert glovebox. − Despite the great progress in all-air-processed PSCs, there is also plenty of room for development.…”

Rapid laser synthesis of surfactantless tantalum‐based nanomaterials as bifunctional catalysts for direct peroxide–peroxide fuel cells

“…19,20 Alternatively, early transition metals have rarely been applied to facilitate H 2 O 2 redox reactions, though Ti and V have found practical uses in polymerization and redox flow batteries. 21,22 Early transition metals, such as Ta, in their oxidized forms can serve as enticing candidates for DPPFCs.…”

“…Though robust noble metals with outstanding catalytic activity can overcome the stability challenge, their prohibitive costs have hindered their widespread applications in the fuel cell industry 19,20 . Alternatively, early transition metals have rarely been applied to facilitate H 2 O 2 redox reactions, though Ti and V have found practical uses in polymerization and redox flow batteries 21,22 . Early transition metals, such as Ta, in their oxidized forms can serve as enticing candidates for DPPFCs.…”

Laser Processing of KBr‐Modified SnO2 for Efficient Rigid and Flexible Ambient‐Processed Perovskite Solar Cells

“…[9,10] TiO 2 and SnO 2 have been utilized extensively as the ETL for the PSCs based on an n-i-p structure due to their suitable energy-level alignment with the perovskite absorber, low cost, and ease of fabrication. [10,11] Compared to TiO 2 , SnO 2 exhibits higher conductivity, stronger electron extraction, higher electron mobility, better energy alignment, and stronger UV resistance. [10] Therefore, tremendous research interest has been drawn to studying and modifying the bulk and surface properties of the SnO 2 to replace the TiO 2 as a more efficient ETL material for PSCs.…”