SiW₁₂–TiO₂ Mesoporous Layer for Enhanced Electron‐Extraction Efficiency and Conductivity in Perovskite Solar Cells

Abstract

High quality electron-transport layer (ETL) with superior optical and electrical properties is an essential part in high efficient perovskite solar cells (PSCs). In this work, SiW -TiO mesoporous film is prepared by a facile one-step spin-coating deposition method and successfully applied as ETL in PSCs. Compared with pristine TiO -based PSC, the SiW -TiO -based one shows a remarkable enhanced power conversion efficiency (PCE) from 12.00 to 14.66 %, which is owed to the higher conductivity, electron-extraction efficiency, and well-matched energy level alignment of SiW -TiO film. Moreover, the SiW -TiO -based device also shows a good long-time stability in under ambient conditions. This work demonstrates that using polyoxometalates (POMs) to modify the metal-oxide semiconductors is an effective approach for further enhancing the performance of PSCs.

Regulated Film Quality with Methylammonium Bromide Addition in a Two‐Step Sequential Deposition to Improve the Performance of Perovskite Solar Cells

“…In agreement with the previous investigation,t he EIS curves of our devicesa re mainly composed of two distinct semicircles.F or the MAPbI 3Àx Br x -basedP SCs,a ccording to the arch of the curves,w eo bserved as maller charge transfer resistance (R tr )a tt he perovskite-HTM interfacea nd a higher charge recombination resistance (R rec )a tt he TiO 2perovskite interface than that of the MAPbI 3 -based PSCs. [30,31] Meanwhile,as maller interceptp oint value at the real part of the Nyquist plots can be obtained if the high-frequency semicircle regioni se xtended, which demonstrates a reduced series resistance (R s )f or the MAPbI 3Àx Br x -based PSCs compared with the pristine MAPbI 3 -based PSCs.C learly,a saresult of the use of the same depositionp rocess for the ETM and HTM, the variation of the resistance (R)t owards the optimizationo ft he device performancec an be attributed to the contribution of the high-quality MAPbI 3Àx Br x perovskite film with MABr addition. Incidentp hoton-toelectron conversion efficiency (IPCE)m easurements were performed to give af urther understandingo ft he improved performance of the MAPbI 3Àx Br x -based PSCs,a nd the IPCE spectra are presented in Figure 7c.T he MAPbI 3Àx Br x -based PSCs present ah igher light response in the whole visiblelight ranget han the MAPbI 3 -based device.…”

“…In agreement with the previous investigation, the EIS curves of our devices are mainly composed of two distinct semicircles. For the MAPbI 3− x Br x ‐based PSCs, according to the arch of the curves, we observed a smaller charge transfer resistance ( R tr ) at the perovskite–HTM interface and a higher charge recombination resistance ( R rec ) at the TiO 2 –perovskite interface than that of the MAPbI 3 ‐based PSCs . Meanwhile, a smaller intercept point value at the real part of the Nyquist plots can be obtained if the high‐frequency semicircle region is extended, which demonstrates a reduced series resistance ( R s ) for the MAPbI 3− x Br x ‐based PSCs compared with the pristine MAPbI 3 ‐based PSCs.…”

MAPbI3 Incorporated with Carboxyl Group Chelated Titania for Planar Perovskite Solar Cells in Low-Temperature Process

“…The decrease of the charge recombination rate did not lead to increasing Voc [49], which might result from the coverage increase of perovskite film to inhibit the penetration of hole-transport-material solution [50]. In general, TiO 2 particles are coated on the cathode as a mesoporous layer for PVSC fabrication [51,52,53,54,55,56,57,58,59,60,61]. In order to further realize the function of h-TAc on PVSCs, we also fabricated PVSCs with h-TAc as a mesoporous layer (PVSC-meso) instead of incorporating h-TAc into the perovskite layer.…”

Ultrasonic‐Assisted Wet Chemistry Synthesis of Ultrafine SnO2 Nanoparticles for the Electron‐Transport Layer in Perovskite Solar Cells

“…The TiO 2 mesoporous-based devicesd elivered high efficiencies. [2] However,a high temperature (> 450 8C) sintering step is required for the mesoporousl ayer,w hich limits its use in flexible devices and increases the productioncost of PSCs. [3] Moreover,the sensitivity of the TiO 2 mesoporous layer to UV radiation contributes to the degradation of the perovskite layer.I nP SCs with ap lanar structure, the perovskite layer is mostly sandwiched between the electron-and hole-selective layers,w hich facilitates transport of the photogenerated charges andb locks undesirable charge recombination.…”