Efficiency and Stability Enhancement of Fully Ambient Air Processed Perovskite Solar Cells Using TiO₂ Paste with Tunable Pore Structure

Abstract

Crystallization and nucleation of the perovskite layer in the mesoscopic perovskite solar cells (PSCs) depend on the nucleation sites of the electron transport layer (ETL). The porosity optimization of TiO2 film as an efficient ETL plays an important role in the performance improvement of PSCs. In the present study, nontoxic carbon spheres synthesized with uniform morphology and controllable size under hydrothermal conditions and used as a template to generate the tunable porous TiO2 films. Furthermore, the effect of porosity modification of TiO2 on the formation of perovskite films with large grain size is studied in an ambient atmosphere with humidity higher than 50%. The best TiO2 film is produced with carbon spheres 8 wt% (C8), which results in the formation of a pinhole‐free, and compact‐packed perovskite layer. The fully air processed PSC device with the ETL made of C8 film exhibits an efficiency of 16.66% with reduced hysteresis, which is much superior in performance compared to the standard cell (11.72%). It is believed that this porosity optimization of TiO2 layer is a simple practical strategy for improved stability of fully air processed efficient perovskite solar cells and usable for the fabrication of reproducible compact perovskite layers in uncontrolled laboratories.

Film Deposition Techniques Impact the Defect Density and Photostability of MAPbI3 Perovskite Films

“…The disadvantages of this method are the necessity for applying an antisolvent during a spin-coating process and the challenges associated with the large-area film formation, which make it less promising for mass production . Although there are several studies featuring high-performance perovskite solar cells fabricated using the one-step coating in air, ,− a two-step deposition technique becomes more and more technologically relevant as it does not require antisolvent quenching . In the two-step deposition of MAPbI 3 , the PbI 2 layer is formed first followed by its further conversion to a perovskite with MAI solution.…”

Charge transport materials for mesoscopic perovskite solar cells

“…For example, carbon spheres with controllable size were shown to act as an effective template for mp-TiO 2 films with tunable porosity which led to a significant enhancement of the PCE from 11.72% to 16.66% and a reduced cell hysteresis. 32 Optimizing TiO 2 pore size for effective perovskite infiltration could also be achieved by employing sub-μm sized polystyrene beads as sacrificial template. 33…”

A Comprehensive Study of CsSnI3-Based Perovskite Solar Cells with Different Hole Transporting Layers and Back Contacts

“…Recently, perovskite semiconductors as absorber layers in perovskite solar cell (PSC) devices have drawn wide interest owing to their exceptional optical and electrical properties [ 1 , 2 , 3 , 4 , 5 , 6 ]. Within a few years, the power conservation efficiency (PCE) of perovskite devices boosted rapidly up to the PCE of 25.8% in 2020 for single-junction perovskite devices, which is comparable with the silicon-based classical photovoltaic devices (PCE of 26.7%) [ 7 ].…”