Enhancing the efficiency and ambient stability of perovskite solar cells via a multifunctional trap passivation molecule

Abstract

In recent times the perovskite solar cells (PVSCs) have emerged as the most preeminent candidates among renewable technologies, yet the instability of PVSCs in ambient condition has hindered its progress...

Mixed Solvent Engineering for Morphology Optimization of the Electron Transport Layer in Perovskite Photovoltaics

“…However, as discussed in the earlier section, the surface roughness for CB 1.0 –DCB 0 was higher, which is ascribed to the rapid volatilization of the lower boiling point solvent that caused an insufficient surface coverage in case of CB 1.0 –DCB 0 . PCBM layers fabricated by the CB 0.5 –DCB 0.5 solvent were observed to have a high light absorption compared to other samples (as shown in the inset of Figure a), which might be attributed to the better film quality with reduced surface roughness and enhanced crystallinity of perovskite/PCBM CB 0.5 –DCB 0.5 , , which further supported the results obtained through AFM (Figure ) and GIXRD data (Figure S3).…”

“…47 However, as discussed in the earlier section, the surface roughness for CB 1.0 −DCB 0 was higher, which is ascribed to the rapid volatilization of the lower boiling point solvent that caused an insufficient surface coverage in case of CB 1.0 −DCB 0 . PCBM layers fabricated by the CB 0.5 −DCB 0.5 solvent were observed to have a high light absorption compared to other samples (as shown in the inset of Figure 3a), which might be attributed to the better film quality with reduced surface roughness and enhanced crystallinity of perovskite/PCBM CB 0.5 −DCB 0.5 , 47,48 which further supported the results obtained through AFM (Figure 2) and GIXRD data (Figure S3). The mixed solvent strategy of using high boiling point solvents for ETL fabrication helps in the penetration of the ET organic molecule into the perovskite film below, which tends to develop a pseudo-bulk heterojunction and repair the defects of perovskite film, 25 further evidenced through PL results.…”

Ambient Stable Perovskite Solar Cells through Trifluoro Acetic Acid-Mediated Multifunctional Anchoring

“…Among various organic molecules, the one with carboxylic acid functional groups are the most commonly used as they are known to interact efficiently with defects in the perovskite layer. − Acetic acid is also utilized to passivate the perovskite either in the bulk or by using it in the antisolvent step at the surface. , Also, fluoro group containing organic materials as the additive in precursor solution makes the perovskite moisture-resistant, improving the ambient stability of the device. Besides, the fluoro groups are known to slow the crystallization process which helps in the formation of large-grain perovskite films with improved crystallinity. − Importantly, many multifunctional additives have been used to passivate the perovskite for increasing both the efficiency and stability of the PSCs; − however, the roles of both carboxylic acid and fluoro groups are not well explored together for the passivation of perovskite in solar cell applications. Such strategic passivating agents can offer multiple advantages such as interaction with the perovskite for reducing the defects, increasing its hydrophobicity, and formation of large-grain polycrystalline perovskite films. , …”

Triple Passivation Approach to Laminate Perovskite Layers for Augmented UV and Ambient Stable Photovoltaics

“…Modification of the transport layer by chemical doping is the most recognized strategy for UV stabilization of the perovskite layer. − One more efficient technique for increasing UV stability is utilizing certain materials with strong UV absorption. − Multifunctional organic molecules having absorption in the UV region can potentially enhance the durability of PSCs under UV irradiation. , Such molecules can simultaneously passivate the defect states and improve device efficiency as well as their long-term stability. − All of these passivation molecules are generally utilized for interface passivation or bulk passivation (by adding in the precursor solution) of perovskites. In most of the reported literature, the surface passivation layer is either coated on top of perovskites or incorporated as a bottom layer.…”