Dual Ions Passivating FAPbBr₃ Perovskite Quantum Dot Films via a Vacuum Drying Method for Stable and Efficient Solar Cells with an Ultrahigh Open-Circuit Voltage of over 1.67 V

Abstract

Defects located in the surface of quantum dots highly impact carrier dynamics and transfer, which would limit the photoelectric conversion efficiency (PCE) of perovskite quantum dot solar cells. Herein, we deposit high-quality FAPbBr 3 quantum dot films through passivating Pb salts and conducting damage-free drying processes. The results indicate that the process of PbBr 2 treatment and vacuum drying process fill both the Pb 2+ and Br − vacancies and minimize the damage of the FAPbBr 3 quantum dot film. The device assembled with this film achieved a champion PCE of 3.11% and involved an ultrahigh open-circuit voltage of 1.67 V or more. In addition, both the corresponding FAPbBr 3 quantum dot films and devices exhibited higher humidity stability than the control films and devices. These studies will provide insights for designing high-quality perovskite quantum dot films with superior optoelectronic properties.

Construction Au/FAPbI3 Schottky Heterojunction towards a High-Speed Electron Transfer Channel for High-Performance Perovskite Quantum Dot Solar Cells

“…This phenomenon results from more efficient electron transfer from the Au/FAPbI 3 film to the SnO 2 electron transport layer through HETC. , Carrier dynamics were extracted from GSB decay data using the exponential fitting approach (Figure S21 and Table S7), where τ 1 and τ 2 correspond to the charge transfer process and nonradiative recombination, respectively. The average lifetime (τ ave ) decreased from 3755.24 ps to 2880.48 ps , indicating that Au/FAPbI 3 films exhibit more effective electron transport compared to FAPbI 3 films . The phenomenon is also observed in the transient absorption spectroscopy (TAS) measurement of the structure of the FAPbI 3 and Au/FAPbI 3 films without SnO 2 , as depicted in Figures S22 and S23, further validating the electron transfer of excited states from FAPbI 3 QDs to Au dots.…”

“…The average lifetime (τ ave ) decreased from 3755.24 ps to 2880.48 ps, indicating that Au/ FAPbI 3 films exhibit more effective electron transport compared to FAPbI 3 films. 46 The phenomenon is also observed in the transient absorption spectroscopy (TAS) measurement of the structure of the FAPbI 3 and Au/FAPbI 3 films without SnO 2 , as depicted in Figures S22 and S23, further validating the electron transfer of excited states from FAPbI 3 QDs to Au dots. Moreover, the four-probe method was used to measure the conductivity of the FAPbI 3 and Au/FAPbI 3 films.…”

“…A larger R rec value suggests smaller photogenerated charge recombination in an Au/FAPbI 3 -based device. 46 Furthermore, a comparison of Mott−Schottky curves (shown in Figure S24) reveals that the built-in potential of Au/FAPbI 3 -based devices (1.07 V) exceeds that of FAPbI 3 -based devices (1.03 V), indicating superior ability of Au/FAPbI 3 -based devices to facilitate charge separation and suppress carrier recombination through HETC. 50 The light intensity dependence of J SC and V OC is illustrated in Figure 6e,f after linear fitting.…”

Recent advance of high-quality perovskite nanostructure and its application in flexible photodetectors

“…Due to their unique size and structure, 0D perovskite nanomaterials often exhibit advantageous optoelectronic properties. High-quality perovskite nanoparticles can be synthesized through various methods, including ultrasonication, ligand-assisted antisolvent, hot injection, and ion exchange processes [90][91][92][93][94][95][96][97].…”

Amino Acid Double-Passivation-Enhanced Quantum Dot Coupling for High-Efficiency FAPbI3 Perovskite Quantum Dot Solar Cells

“…Colloidal quantum dots (QDs) have attracted extensive attention in recent decades owing to their distinct characteristics, such as low-cost solution processability, band gap tunability, chemical stability, and so on, which make them an excellent candidate material for new-generation photovoltaics. − Especially, when the ion size of QDs is reduced to Bohr radius or even smaller, it would have an unique quantum confinement effect, such as size-dependent emission wavelength, adjustable band gap, and high photoluminescence (PL) quantum yields. , In addition, the multiexciton effect of QDs provides a new perspective to break through the theoretical limitation of the photoelectric conversion efficiency (PCE) of PQDSCs. , In the family of PQDs, FAPbI 3 PQDs have excellent ambient stability, long carrier lifetime, and an ideal band gap (1.52 eV), which provides a theoretical foundation for the fabrication of PQDSCs. ,, Yang et al first prepared FAPbI 3 -based PQDSCs by adjusting the antisolvent polarity in the film post-treatment process, with an efficiency of 8.38% . After that, Wang et al introduced protonated oleylamine (OAm) in situ to strengthen the ligand binding at the surface of FAPbI 3 PQDs, and their PCE was enhanced to 13.80% .…”