Understanding the Mechanism of PbCl₂ Additive for MAPbI₃‐Based Perovskite Solar Cells

Abstract

PbCl2 additive engineering is an effective method to decrease the charge accumulation in devices. Herein, the influence of PbCl2 additive on the charge transport properties of inverted planar MAPbI3 perovskite devices is investigated by capacitance–voltage (C–V) spectroscopy. The C–V curves show that the ΔVpeak of the MAPbI3−xClx‐based device is decreased compared to the undoped device, indicating that the introduction of chloride ions effectively mitigates charge accumulation at the interface. Simultaneously, it is proposed that the introduction of chloride ions into the perovskite lattice can decrease the trap density, which promotes charge carrier separation/transport at the electrode interfaces/absorber interface, as evidenced by photoluminescence measurements. The findings of this study clarify that trap states and charge accumulation in the MAPbI3 perovskite solar cell have a considerable influence on carrier separation/transport, enhancing the device performance to ultimately achieve power conversion efficiency (PCE) from 12.3% to 15.5%. Accordingly, this work paves the way for further improving the efficiency of perovskite solar cells.

Interface passivation using choline acetate for efficient and stable planar perovskite solar cells

“…The PL intensity was signicantly increased for the ChAc passivated lm, indicating fewer defects in the ChAc passivated perovskite lms, and consequently minimized non-radiative recombination. 40,41 To verify the passivation effect of ChAc on the perovskite, we conducted the space-charge limited current (SCLC) measurement of pristine and ChAc passivated devices. Fig.…”

“…The PL intensity was significantly increased for the ChAc passivated film, indicating fewer defects in the ChAc passivated perovskite films, and consequently minimized non-radiative recombination. 40,41…”

Improved Performance of Air-Processed Perovskite Solar Cells via the Combination of Chlorine Precursors and Potassium Thiocyanate

“…They achieved excellent efficiencies and long-term stability with FACl and CsCl. PbCl 2 was also reported to facilitate longer charge carrier lifetime and electron–hole collection efficiency as the result of the improved perovskite crystallinity. , Nevertheless, the role of cationic chlorides in enhancing and stabilizing the PV characteristics of air-processed PSCs is still not understood. In particular, the bonding nature of Cl in the precursor, its effects on PSC performance, and their long-term stability have not been studied, considering that Cl can be bound to either a cation at the A-site or a core metal at the B-site.…”