Recent Progress in Perovskite Solar Cells Modified by Sulfur Compounds

Abstract

In the past decade, organic–inorganic hybrid perovskite solar cells (PSCs) have begun to be increasingly studied worldwide owing to the superior properties of perovskite material. However, some issues have delayed their commercialization, such as their long‐term stability, cost reduction, scale‐up ability, and efficiency. The introduction of sulfur to PSCs can relieve the above issues because sulfur can passivate interfacial trap states, suppress charge recombination, and inhibit ion migration, thereby enhancing the stability of PSCs. Furthermore, PbS bonds provide new channels for carrier extraction. Herein, the sulfur‐based compounds utilized in PSCs are summarized and classified according to their functions in the different layers of PSCs. The results indicate that these sulfur‐based compounds have efficiently promoted the commercialization of PSCs. It is hoped that this review can help others understand the intrinsic phenomena of sulfur‐based PSCs and motivate additional investigations.

1T-Rich 2D-WS2 as an interfacial agent to escalate photo-induced charge transfer dynamics in dopant-free perovskite solar cells

“…As shown in Figure 2a the Pb4f5/2 and Pb4f7/2 peaks of the bare perovskite layers located at 142.98 and 138.1 eV respectively, these peaks show an apparent binding energy shift of 0.11 eV towards the higher binding region with the presence of 2D-WS2 layer. A similar binding energy shift can be deduced in I3d peaks when the perovskite layer is placed with 2D-WS2 in which the shift is around 0.15 eV (Figure 2b), corroborating a possible strong interaction of S-Pb, S-I, and modified chemical environment of [PbI6] 4octahedral 34,38,39 . No visible changes were noted in the UV-visible spectra of the perovskite with/without the 2D WS2 interface layer (Figure S4).…”

Novel Phenothiazine‐Based Self‐Assembled Monolayer as a Hole Selective Contact for Highly Efficient and Stable p‐i‐n Perovskite Solar Cells

“…[35] In addition, numerous reports have indicated that the sulphur can passivate interfacial trap states, suppress charge recombination and inhibit ion migration, thereby enhancing the stability and performance of PSCs. [36,37] Subsequently, electron-withdrawing Br groups were introduced as substituents in the phenothiazine moiety to better align the energy levels with the perovskite materials, by modifying the work function (WF) of the transparent conductive oxide (TCO) substrate through its permanent dipole moment (vide infra). Moreover, Br-terminal functional groups may play an additional role in PSCs.…”

“…[ 35 ] In addition, numerous reports have indicated that the sulphur can passivate interfacial trap states, suppress charge recombination and inhibit ion migration, thereby enhancing the stability and performance of PSCs. [ 36,37 ]…”

Effects of Chemical Valences of Sulfur on the Performance of CsFAMA Perovskite Solar Cells

“…Small molecules with lower cost and better process compatibility were also demonstrated with a similar effect on defect passivation and performance improvement. It has been reported that alkali metal ions such as K + and Na + and halogen ions such as Cl – , Br – , and I – can modify the electron transport layer and passivate the interface defects, which not only improves the distribution of defects and the binding energy of defects but also promotes interface charge transportation. − In addition, many sulfur-based additives were introduced to modify the perovskite from different aspects such as controlling nucleation processes, improving phase stability, and stabilizing perovskite precursors . Han et al demonstrated that the SCN – ions could coordinate with Pb 2+ ions in the precursor, leading to the improvement of the stability and reduction of the defect density in PVK layers.…”