Recent Progress in Perovskite Materials Using Diammonium Organic Cations Toward Stable and Efficient Solar Cell Devices: Dion–Jacobson

Abstract

Perovskite solar cells have been intensively studied recently due to their superb optoelectronic properties and rapidly increasing power conversion efficiency. However, perovskite solar cells with the AMX3 structure as the light‐absorbing layer have a big stability problem. Multiple alternatives have been developed to ensure their stability, such as dimensional engineering (2D and 2D/3D), which consists of the incorporation of large organic cations into the perovskite structure. Research in dimensional engineering has been prevalent in the Ruddlesden–Popper phases. The presence of this large cation slows the decomposition and improves the stability of perovskites. Thus, new 2D perovskites are being studied based on Dion–Jacobson (DJ) phases, consisting of the addition of diammonium cations and leading to the formation of 2D and 2D/3D perovskites with better stability due to their hydrogen bonding on both sides. Moreover, 2D DJ perovskites offer the advantage of decreasing the gap between layers with higher contacts, which improves not only their optoelectronic properties, but also their charge transport properties. This article begins with an overview of the crystal structure and optoelectronic characteristics of 2D perovskites. Then, the progress achieved currently in using DJ‐phase perovskites in photovoltaic is assessed. Finally, the possible research routes for producing low‐dimensional perovskites are highlighted.

Origin of Broad Emission Induced by Rigid Aromatic Ditopic Cations in Low-Dimensional Metal Halide Perovskites

“…35 Recent reports showed improved charge transport properties using diammonium cations in 2D Dion-Jacobson (DJ) MHPs, likely caused by a decrease in the gap between the 2D MHPs with charge transport layers. 36 Even more interestingly, broadband white light emission has been observed in (N-MEDA)PbBr 4 (N-MEDA = N 1 -methylethane-1,2-diammonium) and (EDBE)PbX 4 (EDBE = 2,2′-(ethylenedioxy)bis(ethylammonium); X = Cl, Br), as well as for its tin-based counterpart (EDBE)SnI 4 . 37,38 Recently, broadband emission was also observed in 2D lead bromide perovskites with ditopic aromatic cyclic cations, likely being correlated to the level of octahedral distortion.…”

“…ortho- , meta- and para- isomers of (phenylene)­di­(ethylammonium) iodide have been used as passivating layers in perovskite solar cells, boosting the efficiency and long-term stability . Recent reports showed improved charge transport properties using diammonium cations in 2D Dion-Jacobson (DJ) MHPs, likely caused by a decrease in the gap between the 2D MHPs with charge transport layers …”

Emerging Opportunities in Lead-Free and Lead–Tin Perovskites for Environmentally Viable Photodetector Applications

“…50 The DJ structure is similar to the RP structure, wherein the only difference is that the large diammonium organic cations (NH 3 + RNH 3 + ) are located between each quantum well as formulated by (NH 3 RNH 3 )A n−1 Sn n X 3n+1 . 51,52 2D perovskites allow more variety in optoelectronic properties affected by the stoichiometric ratios between the A-site and the large organic cation (LOC) site, the chemical structure of the LOC, A sites, and X sites. 46,53 In the 2D perovskite structure, n layers of [MX 6 ] 4− octahedral sheets are sandwiched between the insulating layers of the LOC (RNH 3 + ) to produce natural multiple-quantumwell structures.…”

“…The general formula of a RP 2D perovskite is (RNH 3 ) 2 A n –1 Sn n X 3 n +1 ( n = 1, 2, 3, 4, ...), where RNH 3 is a large aliphatic or aromatic alkylammonium spacer cation, e.g., butylammonium (BA) or phenyl ethylammonium (PEA), and n represents the number of [MX 6 ] 4– octahedral layers within each quantum well . The DJ structure is similar to the RP structure, wherein the only difference is that the large diammonium organic cations (NH 3 + RNH 3 + ) are located between each quantum well as formulated by (NH 3 RNH 3 )­A n –1 Sn n X 3 n +1 . , 2D perovskites allow more variety in optoelectronic properties affected by the stoichiometric ratios between the A-site and the large organic cation (LOC) site, the chemical structure of the LOC, A sites, and X sites. , …”

Additive Engineering for Stable and Efficient Dion–Jacobson Phase Perovskite Solar Cells

“…Even though these materials appear to have better chemical stability in a variety of environmental settings [ 5 , 17 ], their photovoltaic performance is typically worse than that of three-dimensional (3D) halide PVK [ 18 , 19 ], primarily because the intrinsic van der Waals gap hinders carrier transport across the long organic spacers [ 20 – 23 ]. To attain improved steadiness although limiting carrier transport in solar cells, it is important to look into strategies to offset the unfavorable impacts of such interlayer constructions as those observed in RP-layered halide perovskites [ 24 – 27 ].…”