Facet-Dependent Passivation for Efficient Perovskite Solar Cells

Abstract

Understanding the interplay between the surface structure and the passivation materials and their effects associated with surface structure modification is of fundamental importance; however, it remains an unsolved problem in the perovskite passivation field. Here, we report a surface passivation principle for efficient perovskite solar cells via a facetdependent passivation phenomenon. The passivation process selectively occurs on facets, which is observed with various post-treatment materials with different functionality, and the atomic arrangements of the facets determine the alignments of the passivation layers. The profound understanding of facet-dependent passivation leads to the finding of 2amidinopyridine hydroiodide as the material for a uniform and effective passivation on both (100) and ( 111) facets. Consequently, we achieved perovskite solar cells with an efficiency of 25.10% and enhanced stability. The concept of facet-dependent passivation can provide an important clue on unidentified passivation principles for perovskite materials and a novel means to enhance the performance and stability of perovskite-based devices.

Computational Design of Optimized Modular Photovoltaic Electrochemical Reactor for Energy Efficient CO2‐to‐Cn Reduction Reaction with Bandgap Tunable Perovskite Tandem Cells

“…Considering ever-growing PCE and lifetime, as well as stability under humidity and high in-operando temperature for external usage associated with large-area applicability, [17][18][19][20][21][22][23][24] hybrid organic-inorganic metal halide ABX 3 (where A and B are the cations such as MA, FA or Cs ions for A cations, and Pb or Sn ions for B cations, and X is the halide anions), perovskite solar cells (PSCs) can work as the ideal electrical energy source for PV. In addition, an EC system with wire-connected PV can further benefit from the optimized voltage design of the PSCs.…”

“…We assumed that the metal halide ABX 3 perovskite materials such as MAPbX 3 , FAPbX 3 , and CsPbX 3 have the same cubic crystalline structures at ambient conditions, irrespective of the composition of the halides. [17][18][19][20][21][22][23][24][25] To construct a GNN, the coordinates and topology of the atoms in the unit crystalline structures were translated into a form of graph (refer to Figure 9a). [36] For the training data set, we employed public databases obtained from the density functional theory (DFT)-based calculated bandgaps reported in Automatic Flow (AFLOW), [37] Open Quantum Materials database (OQMD), [38] and Materials Project.…”

“…Since first reported in 2009, hybrid organic metal halide perovskite materials have been extensively applied for PV due to their competitive photon-to-electron conversion efficiency, extended durability, easy processability, and inexpensive cost for commercial uses. [17][18][19][20][21][22] One of the exceptional benefits of metal halide perovskite materials for PV is the tunability of the bandgap (E g ) in the broadband solar spectrum. In particular, Pb-and Snbased metal halide perovskite materials exhibit wide tunability of E g spanning from near-infrared to ultraviolet, covering most of the intensive range of the solar irradiance spectrum at AM 1.5 conditions.…”

“…The tunability is derived from the feasibility of the design of the composition of the cations (i.e., A = Cs + , methyl ammonium cation (MA + = (CH 3 NH 3 ) + ), or formamidine ammonium cation (FA + = (CH(NH 2 ) 2+ )) as well as of the halide ions (i.e., X = I − , Br − or Cl − ) in ABX 3 (where B = metal (i.e., Pb or Sn)) without deteriorating the crystalline structures of the unit cell pertaining symmetry and favorable crystal facets when formed in thin film shape. [20][21][22][23][24][25] Basically, these ABX 3 -type metal halide perovskite materials can be processed in a simple process at ambient conditions to prepare designated profile of bandgap along thickness direction inside the thin film which is matched with energy levels of relevant hole-and electron-transfer layers in the PV cell. [20][21][22] Therefore, it is possible to prepare tandem or multijunction PVs covering a broad spectrum, pursuing maximum energy efficiency with stable interface control, and sustaining thin film morphological stability.…”

“…[20][21][22][23][24][25] Basically, these ABX 3 -type metal halide perovskite materials can be processed in a simple process at ambient conditions to prepare designated profile of bandgap along thickness direction inside the thin film which is matched with energy levels of relevant hole-and electron-transfer layers in the PV cell. [20][21][22] Therefore, it is possible to prepare tandem or multijunction PVs covering a broad spectrum, pursuing maximum energy efficiency with stable interface control, and sustaining thin film morphological stability. The possibility of the construction of multijunction thin-film metal halide perovskite PV cells can be extended to other PV-based energy devices, in-cluding EC reactors.…”