ABSTRACT
Singlet fission (SF) materials have been applied in various types of solar cells to pursue higher power conversion efficiency (PCE) beyond the Shockley-Queisser (SQ) limit. SF implementation in perovskite solar cells has not been successfully realized yet due to the insufficient understanding of the SF/perovskite heterojunctions. In this work, we attempt to elucidate the charge dynamics of an SF/perovskite system by incorporating a well-known SF molecule, TIPS-pentacene, and a triple-cation perovskite Cs0.05(FA0.85MA0.15)0.95PbI2.55Br0.45, owing to their well-matched energy structures. The transient absorption spectra and kinetic fitting plots suggest an electron-transfer process from the triplet state of TIPS-pentacene to perovskite in the picosecond regime, which increases the carrier density by 20% in the perovskite layer. This work confirms the existence of an electron-transfer process between the SF material and perovskite, providing a pathway to SF-enhanced perovskite solar cells.
ABSTRACT
The increasing demand for large-scale manufacture of wearable electronics requires applicable energy storage devices with high-performance and safety. In this paper, we reported a solid-state Zn battery based on a free-standing organic cathode and metal Zn anode with an orderly aligned nano-architecture. The cathode is fabricated by depositing organic nanowire arrays on a carbon nanotube film via an in situ polymerization process, and the anode was prepared by electrodepositing Zn nanosheet arrays on carbon cloth. To avoid electrolyte leakage risks, a pseudo-solid-state PAAM-ZnSO4 gel electrolyte is employed, which is synthesized via a chemical cross-linking and film casting approach. The orderly aligned nanostructure of PANI nanowire arrays and zinc nanosheet arrays exhibits superior electrochemical performance, while the free-standing electrode configuration simplifies the battery fabrication process and offers excellent flexibility. The resulting solid-state Zn battery delivered a high capacity of 144 mA h g-1 at a current density of 0.2 A g-1, a 91.1% capacity retention after 150 cycles at a current density of 0.5 A g-1, and excellent flexibility under different bending states. This high-performance solid-state Zn battery provides a promising alternative energy storage device for next generation wearable electronics.
