TiO₂quantum dots as superb compact block layers for high-performance CH₃NH₃PbI₃perovskite solar cells with an efficiency of 16.97%

Abstract

A compact TiO(2) layer is crucial to achieve high-efficiency perovskite solar cells. In this study, we developed a facile, low-cost and efficient method to fabricate a pinhole-free and ultrathin blocking layer based on highly crystallized TiO(2) quantum dots (QDs) with an average diameter of 3.6 nm. The surface morphology of the blocking layer and the photoelectric performance of the perovskite solar cells were investigated by spin-coating with three different materials: colloidal TiO(2) QDs, titanium precursor solution, and aqueous TiCl(4). Among these three treatments, the perovskite solar cell based on the TiO(2) QD compact layer offered the highest power conversion efficiency (PCE) of 16.97% with a photocurrent density of 22.48 mA cm(-2), a photovoltage of 1.063 V and a fill factor of 0.71. The enhancement of PCE mainly stems from the small series resistance and the large shunt resistance of the TiO(2) QD layer.

Modulated CH3NH3PbI3−xBrx film for efficient perovskite solar cells exceeding 18%

“…A mesoporous TiO 2 film was deposited on compact TiO 2 layer by spin-coating TiO 2 paste diluted in ethanol. TiO 2 paste was prepared as described previously495051. After drying at 100 °C for 5 min, the film was annealed at 450 °C for 30 min, providing a thickness of ca.…”

Tuning the Fermi Level of TiO2 Electron Transport Layer through Europium Doping for Highly Efficient Perovskite Solar Cells

“…The Eu/TiO 2 colloid was obtained by hydrothermal synthesis. TiO 2 paste was prepared as described previously: Tetra‐ n ‐butyl titanate (5 mL) was poured quickly into deionized water (50 mL), and the mixture was stirred for 30 min to complete the hydrolysis process. Then, the solution was filtered and the solid was retrieved.…”

“…Fluorine‐doped tin oxide (FTO)‐coated glass was cleaned with distilled water, ethanol, isopropanol, acetone, and ethanol by ultrasonication for 30 min for each solvent. A TiO 2 blocking‐layer (bl‐TiO 2 ) was deposited on the cleaned FTO glass by spin‐coating the TiO 2 solution at 4000 rpm for 30 s and then annealing at 550 °C for 30 min . A mesoporous TiO 2 layer was deposited onto the bl‐TiO 2 /FTO substrate by spin‐coating the as‐synthesized pure‐TiO 2 and Eu/TiO 2 colloid at 3000 rpm for 30 s and then annealing at 550 °C for 30 min.…”

Addition of Lithium Iodide into Precursor Solution for Enhancing the Photovoltaic Performance of Perovskite Solar Cells

“…Methylammonium iodide (MAI) was purchased from Xi′an Polymer Light Technology Crop. The compact‐TiO 2 (c‐TiO 2 ) layer was prepared according to the method reported by Tu et al . whereas mesoporous TiO 2 (m‐TiO 2 ) layer was prepared as described previously …”

“…The glass was immersed in an aqueous solution of titanium tetrachloride (0.02 m ) at 80 °C for 20 min and then sintered at 550 °C for 30 min again, cooled to room temperature before depositing the precursor solution (20 μL) at a spinning speed of 4000 rpm for 20 s and again annealing at 100 °C for 10 min. The spiro‐MeOTAD layer was spin‐coated onto the perovskite film at 4000 rpm for 20 s according to literature . Finally, an 80 nm‐thick Au electrode was deposited through thermal evaporation under a vacuum of 1.33×10 −4 Pa.…”