Compact TiO₂/Anatase TiO₂ Single-Crystalline Nanoparticle Electron-Transport Bilayer for Efficient Planar Perovskite Solar Cells

Abstract

Electron-transport layer (ETL)/perovskite interface modification plays a key task for producing efficient planar perovskite solar cells (PSCs). In this study, interfacial modification of compact TiO2 using novel, one-step hydrothermally synthesized single-crystalline anatase (AT) titania nanoparticles (TiO2 NPs) (average diameter = 6–10 nm) was applied as an ETL bilayer to enhance the efficient charge generation and extraction and eliminate the electron–hole recombination ratio. We report here an easy approach for enhancing the performance of planar PSCs by introducing a compact TiO2/AT TiO2 NPs bilayer through spray pyrolysis (SP) deposition and spin-coating (SC) techniques, respectively. The enhanced performance of the devices with an SP-TiO2/SC-AT TiO2 NPs bilayer facilitated more efficient electron transport, charge extraction, and low interfacial recombination. Ultimately, the best device had a 17.05% power conversion efficiency resulting from the significant decrease in J–V hysteresis, presenting almost a 12% performance improvement compared to the TiO2 only layer-based counterpart. Thus, the present study provides an important advance to the design of photovoltaic devices with respect to charge transport and electron–hole recombination.

Spray Pyrolyzed TiO2 Embedded Multi-Layer Front Contact Design for High-Efficiency Perovskite Solar Cells

“…Furthermore, TiO 2 can produce a smooth film surface to improve charge transfer while maintaining the uniformity [19,23]. Several deposition methods, such as spin-coating, spray pyrolysis deposition (SPD), atomic layer deposition (ALD), chemical vapor deposition (CVD), sputtering, have been used to prepare TiO 2 compact layer (CL) [18,19,23,[26][27][28][29][30]. The current work investigates the preparation of high-quality (compact, uniform, and reproducible) TiO 2 films by the SPD technique so that the film can be used as an ETL for the fabrication of efficient PSCs.…”

Low-Temperature Processed TiOx Electron Transport Layer for Efficient Planar Perovskite Solar Cells

“…High-quality mesoporous TiO 2 scaffold films and TiO 2 CL require a high-temperature sintering (> 450 °C) step, which limits their applications in future flexible PSCs and solar modules. The active surface area and performance of the devices was improved by forming the perovskite layer on a layer composed of TiO 2 CL/TiO 2 nanoparticles [ 16 , 17 , 18 ]. The development of PHJ PSCs with low-temperature processed (< 150 °C) ETL CLs has attracted significant attention for their simple device framework [ 19 ].…”

Quantum dot-modified titanium dioxide nanoparticles as an energy-band tunable electron-transporting layer for open air-fabricated planar perovskite solar cells

“…This quenching phenomenon indicated that the charge separation process is effectively occurred by the electron transfer from the conduction band of CdS to the conduction band of TiO 2 with low recombination rate. 33,35,36 Figure 2 shows XRD patterns of the TiO 2 nanoparticles without and with CdS QDs (2%, 6%, and 10%). The characteristic peak positions at 25.3 (101), 37.6 (004), 47.9 (200), 54.7 (105), 62.7 (204), and 75.1 (215) appeared in all samples, corresponding to the anatase-TiO 2 phase.…”