Spidermen Strategy for Stable 24% Efficiency Perovskite Solar Cells

Abstract

The interface energetics‐modification plays an important role in improving the power conversion efficiency (PCE) among the perovskite solar cells (PSCs). Considering the low carrier mobility caused by defects in PSCs, a double‐layer modification engineering strategy is adopted to introduce the “spiderman” NOBF4 (nitrosonium tetrafluoroborate) between tin dioxide (SnO2 and perovskite layers. NO+, as the interfacial bonding layer, can passivate the oxygen vacancy in SnO2, while BF4− can optimize the defects in the bulk of perovskite. This conclusion is confirmed by theoretical calculation and transmission electron microscopy (TEM). The synergistic effect of NO+ and BF4− distinctly heightens the carrier extraction efficiency, and the PCE of PSCs is 24.04% with a fill factor (FF) of 82.98% and long‐term stability. This study underlines the effectiveness of multifunctional additives in improving interface contact and enhancing PCE of PSCs.

Building a Charge Transfer Bridge between g-C3N4 and Perovskite with Molecular Engineering to Achieve Efficient Perovskite Solar Cells

“…For the BFCN, a peak at 1155 cm –1 can be attributed to the C–F stretching vibration and the peak at 1402 cm –1 can be assigned to the B–O stretching vibration. , After mixing with the precursor, both C–F and B–O stretching vibrations shift to a larger wavenumber due to the formation of hydrogen bonding between the halide ion terminal and the boronic acid group of BF . Similarly, the shift of B–O stretching vibration can be ascribed to the formation of the hydrogen bond with the exterior iodides of the octahedron . The shift of the C–F stretching vibration can be ascribed to the ionic bond (Pb–F) interaction between Pb 2+ and BF; meanwhile, the hydrogen bond (N–H···I) between the N–H of FA + /MA + and the halide ion is also one of the reasons …”

“…13 Similarly, the shift of B−O stretching vibration can be ascribed to the formation of the hydrogen bond with the exterior iodides of the octahedron. 62 The shift of the C−F stretching vibration can be ascribed to the ionic bond (Pb−F) interaction between Pb 2+ and BF; meanwhile, the hydrogen bond (N−H•••I) between the N−H of FA + /MA + and the halide ion is also one of the reasons. 63 To fully understand the mechanism of interaction between BFCN and PVK films, the liquid-state 1 H magnetic resonance (NMR) spectra of BFCN with or without precursors in deuterated dimethyl sulfoxide (DMSO-d6) are depicted in Figure 5d−f and Figure S6.…”