Modulating Dual Functionalities of Hydrazide Derivatives for Iodide Oxidation Suppression and Defect Passivation in Printable Mesoscopic Perovskite Solar Cells

Abstract

The oxidation of iodide ions during annealing in air and rich defects generated at crystal terminations in perovskite are major limitations for achieving high photovoltaic performance in printable mesoscopic perovskite solar cells (p‐MPSCs). Here, the dual role of hydrazide derivatives in inhibiting iodide oxidation and passivating crystal termination defects is reported and how the dual role is affected by the substituent is studied. It's found that varying the hydrazide derivative from formylhydrazine (FH) to benzhydrazide (BH) and then to 4‐tert‐butylbenzhydrazide (TBBH) by introducing phenyl and 4‐tert‐butylphenyl substituents enhances the electron donating ability of hydrazides due to substituent electronic effect. The tailored hydrazides present enhanced iodide oxidation suppression and defect passivation capabilities, which lowers the trap density of perovskite in p‐MPSCs significantly. As the most effective additive, TBBH improves the power conversion efficiency of the p‐MPSC from 18.66% to 20.30%, and the resulted device maintains 90% of its initial efficiency after 500 h tacking at maximum power point at 55 ± 5 °C under simulated 1 sun illumination.

Design of strong and weak intermolecular interactions to engineer buried interfaces in inverted wide-bandgap perovskite solar cells

“…Moreover, the average CPD of Hi–Me film was enhanced from around −300 mV to 0 mV compared with Me-4PACz film, which corresponds to a reduced work function. 22,23 The change in work function is also corroborated by Kelvin probe measurements (Fig. S12, ESI†), suggesting the formation of surface negative dipole.…”

Interface-oriented bridges toward efficient carbon-based perovskite solar cells

“…4f, τ rec increased from 0.293 ms to 0.354 ms following PB treatment, indicating significant suppression of non-radiative recombination. 43,44 Furthermore, electrochemical impedance spectroscopy (EIS) was employed to investigate the charge transfer process at the interface. It was observed that the series resistance ( R s ) of PB-SnO 2 was reduced from 71.92 Ω to 69.85 Ω compared to that of SnO 2 , while the recombination resistance ( R rec ) increased from 5032 Ω to 16 703 Ω (Table S4†).…”

Rational regulation strategies toward perovskite precursor inks and perovskite films from the lab to commercialization

“…, diphenyl sulfoxide (DPSO), carbohydrazide (CBH), 4- tert -butylbenzhydrazide (TBBH), and 2-imidazolidinone (IMD)) have been explored as additives to regulate the nucleation and crystallization processes, thereby enhancing the quality of scalable perovskite films. 34,75,169,170 Compared to traditional Lewis base solvents, the introduction of solid Lewis bases can eliminate the solvent residue and prevent the formation of voids at buried interfaces caused by solvent evaporation. Recently, Liu et al reported a simple perovskite precursor ink composed of FAI, PbI 2 and DMF for blade-coating α-FAPbI 3 films in air by introducing the solid Lewis base IMD.…”