Designing New Indene-Fullerene Derivatives as Electron-Transporting Materials for Flexible Perovskite Solar Cells

Abstract

The synthesis and characterization of a family of indene-C 60 adducts obtained via Diels–Alder cycloaddition [4 + 2] are reported. The new C 60 derivatives include indenes with a variety of functional groups. These adducts show lowest unoccupied molecular orbital energy levels to be at the right position to consider these compounds as electron-transporting materials for planar heterojunction perovskite solar cells. Selected derivatives were applied into inverted (p–i–n configuration) perovskite device architectures, fabricated on flexible polymer substrates, with large active areas (1 cm 2 ). The highest power conversion efficiency, reaching 13.61%, was obtained for the 6′-acetamido-1′,4′-dihydro-naphtho[2′,3′:1,2][5,6]fullerene-C 60 ( NHAc-ICMA ). Spectroscopic characterization was applied to visualize possible passivation effects of the perovskite’s surface induced by these adducts.

How Does Spin Play with the Cycloaddition to Paramagnetic Endohedral Metallofullerenes? The Curious Case of TiSc2N@C80

“…We reach basically the same conclusions when considering the reactions taking place in solutions of toluene and orthodichlorobenzene (o-DCB), the two solvents commonly used for Diels–Alder additions to fullerenes and EMFs. − As we can see from Table , for BD addition to TiSc 2 N@C 80 , the stepwise mechanism shows a lower barrier than the concerted one, and this difference is even enlarged in both solvents. Compared to gas-phase reactions, the barriers for all pathways in Table are lowered in both toluene and o-DCB, except for the concerted [6,6] addition in toluene.…”

Effective Interfaces between Fullerene Derivatives and CH3NH3PbI3 to Improve Perovskite Solar Cell Performance

“…X-ray photoelectron spectroscopy (XPS) has been one of the most used experimental techniques to characterize the coordination interactions between the organic additives and the perovskite. In particular, the characterization is based on finding a binding energy decrease (∼0.3 and 0.5 eV) of the Pb 4f signals due to their coordination with a Lewis base compared to the pristine surface. ,,,, We approach this surface characterization by modeling the core-level shift (CLS) of Pb atoms at the PbI 2 -MAPbI 3 surface and their interfaces as the variation in average electrostatic potential between the Pb at the surface and those at the center of the slab, considered bulk. In this way, the models will reproduce the shift experimentally observed when the CLS of the superficial Pb tends toward the values of the Pb atoms in bulk.…”

“…High photoconversion efficiencies (PCE) and stability improvements have been achieved using fullerene derivatives (FD) as the electron transport layer (ETL) in inverted HPSC obtained with MAPbI 3 perovskite. − The [6,6]-phenyl-C 61 -butyric acid methyl ester or PCBMC60 is the ETL used as a reference. Still, novel derivatives have been proposed to reduce costs and to include functionalities that also help to increase stability.…”

“…This strategy has been shown to effectively passivate the perovskite trap states and consequently reduce the current–voltage hysteresis and increase the efficiency of the solar cell. Among others, FD based on pyrrolidine ester, , thiophene, indene, and pyridine , groups allows for the devices with the highest power PCE compared to an equivalent cell built with C 60 or C 70 PCBM. According to these reports, in PCBM derivatives the oxygens are less exposed to interaction with the perovskite surface, whereas this interaction is favored in more novel designs.…”

Rigid Enhanced Electrochemiluminescence of 1,2,3-Triaryl Indenes as an Ultrasensitive Sensor for D2O in H2O

“…Indenes represent a type of important polycyclic aromatic hydrocarbons, which have not only been discovered in many natural products − but also extensively served as synthetic building blocks in materials, organic synthesis, and pharmaceuticals. − To date, considerable efforts have been devoted to developing efficient methods for the synthesis of indenes, and remarkable progress has been achieved in this area. − Since indenes contains highly π-conjugated rigid chemical structures, they are potentially promising candidates for organic photoelectric materials. Indeed, indenes have presented a myriad of applications in the fields of FL sensors, optoelectronics, organic solar cells, and biological imaging in recent years. − …”