Amorphous polymer with CO to improve the performance of perovskite solar cells

Abstract

Morphology and crystallinity of perovskite layers are crucial for power conversion efficiency (PCE) of perovskite solar cells (PSCs).

Stable Sn/Pb-Based Perovskite Solar Cells with a Coherent 2D/3D Interface

“…As we know that solvents containing C=O group such as γ-butyrolactone and N,N-dimethylformamide can interact strongly with the perovskite because the two electron lone pairs on the oxygen atom can make them a Lewis base and coordinate with bivalent metal (Sn 2+ /Pb 2+ ), which acts as a Lewis acid, they are therefore good solvents for the perovskite precursor solution ( Cao et al., 2016 , Cao et al., 2017 ). Moreover, Zhang and coworkers reported that the C=O group in polyvinylpyrrolidone (PVP) could strongly interact with Pb 2+ ions because of the same reason and that such interaction provided a powerful means to modulate the nucleation and growth of CH 3 NH 3 PbI 3-x Cl x perovskite ( Zhang et al., 2017b ). Based on such rationale, we believe that molecules containing C=O group could be a better choice for the formation of vertically oriented 2D low-band-gap perovskite film.…”

Multifunctional Two-Dimensional Conjugated Materials for Dopant-Free Perovskite Solar Cells with Efficiency Exceeding 22%

“…The CO in pure 2DP-TDB polymer exhibits a stretching vibration mode at 1664 cm –1 , which is downward shifted to 1625 cm –1 after binding to the perovskite surface (Figure c). This could be attributed to the electron delocalization in CO due to the formation of Lewis base adducts, suggesting a strong interaction between the undercoordinated Pb 2+ in the perovskite surface and CO in the 2DP-TDB layer. − Note that a weak band at ∼1621 cm –1 in control perovskite film could be ascribed to the flexural vibration mode of H 2 O …”

Enhanced Photovoltaic Properties of Perovskite Solar Cells by Employing Bathocuproine/Hydrophobic Polymer Films as Hole-Blocking/Electron-Transporting Interfacial Layers

“…In addition, hydrophobic PVP has been used as an additive in the perovskite layer to improve PV performance by protecting the perovskite crystals from the damaging effects of moisture; the acylamino groups of PVP enhanced the electron density at the perovskite surface and, thereby, decreased the surface energy and stabilized the perovskite layer; the resulting PVSC displayed a high PCE and excellent moisture-stability [ 35 ]. Furthermore, strong interactions between Pb(II) ions and the C=O groups in PVP can lead to the nuclei distributing uniformly along the PVP chains, resulting in compact MAPbI 3 films; consequently, PVP-added perovskite layers can possess crystalline structures that enhance the PCE-stability of their PVSCs [ 36 , 37 , 38 , 39 ].…”