Solvent Effect on Film Formation and Trap States of Two-Dimensional Dion–Jacobson Perovskite

Abstract

Two dimensional Dion–Jacobson (2D DJ) perovskite has emerged as a potential photovoltaic material because of its unique optoelectronic characteristics. However, due to its low structural flexibility and high formation energy, extra assistance is needed during crystallization. Herein, we study the solvent effect on film formation and trap states of 2D DJ perovskite. It is found that the nucleation process of 2D DJ perovskite can be retarded by extra coordination, which is proved by in situ optical spectra. As a benefit, out-of-plane oriented crystallization and ordered phase distribution are realized. Finally, in 1,5-pentanediammonium (PeDA) based 2D DJ perovskite solar cells (PSCs), one of the highest reported open-circuit voltage (V OC) values of 1.25 V with state-of-the-art efficiency of 18.41% is obtained due to greatly shallowed trap states and suppressed nonradiative recombination. The device also exhibits excellent heat tolerance, which maintains 80% of its initial efficiency after being kept under 85 °C after 3000 h.

Divalent organic cations as a novel protective layer for perovskite materials

“…The difference may be caused by the different settings of parameters. Besides, compared with the ProDMA based 2D DJ perovskite with a PCE of 18.41% (experimental value), 20 our model with ProDMA-PS modication may yield better PCE. Other simulated photoelectric properties further conrm that the modication will not bring adverse effects, as the open-circuit voltages (V OC ) are 1.27 and 1.25 V, the short-circuit current densities (J SC ) are 25.13 and 25.14 mA cm −2 , and the ll factors (FF) are 84.09% and 84.0% before and aer the modication, respectively.…”

“…17,18 The divalent cations connect the inorganic layers of two MAPbI 3 parts by electrostatic interaction, thus achieving a stronger connection and better performance of interlayer charge carrier transport compared with the 2D RP-type PSs. 19 Hang et al 20 researched the 1,5-pentane-diammonium (NH 3 (CH 2 ) 5 NH 3 ) based 2D DJtype PS ((NH 3 (CH 2 ) 5 NH 3 )(MA) 3 Pb 4 I 13 ), which is outstanding in photophysical properties and thermal stability. Note that NH 3 (CH 2 ) 5 NH 3 may also be viewed as MA(CH 2 ) 3 MA, and thus may be denoted as ProDMA (Pro stands for propyl, and D means di-).…”

Diazabicyclic Electroactive Ionenes for Efficient and Stable Organic Solar Cells

“…Although the t DOS increased significantly as the energy levels are above 0.34 eV for all the devices, NDI‐DABC‐based device presents much lower t DOS with respect to PMD‐DABC and PDI‐DABC‐based devices. The lower t DOS means the less charges captured by the trap states in NDI‐DABC‐based OSCs, which can effectively reduce carrier recombination and coincide with the improved FF [65] …”

“…The lower tDOS means the less charges captured by the trap states in NDI-DABC-based OSCs, which can effectively reduce carrier recombination and coincide with the improved FF. [65] The film morphology of the ionene polymers and their interfacial contact with the adjacent electrodes and active layers were studied by a combination of techniques. The structure order of the ionene polymer films was compared by grazing-incidence X-ray diffraction (GIXD), respectively.…”

Incorporating an Aromatic Diammonium To Assemble Bilayered Dion–Jacobson Perovskite Crystals for Weak Light Detection

“…Two-dimensional (2D) Dion–Jacobson (DJ) hybrid perovskites have aroused great attention for assembling high-efficiency optoelectronic devices because they offer greater stability compared to the 2D Ruddlesden–Popper (RP) phase and their three-dimensional (3D) counterparts. − Up to now, in comparison to a variety of 2D RP phase hybrid perovskites, the kind of DJ hybrid perovskite is inferior as a result of the harsh synthetic conditions. ,, Nevertheless, DJ hybrid perovskites have incomparable advantages over RP hybrid perovskites in some aspects, for example, the better carrier transport along the out-of-plane direction, the more lattice rigidity, the shorter interlayer spacing, and the longer term stability under vigorous operation conditions . Specifically, the transport of carriers along the out-of-plane direction is comparable to along the in-plane direction in DJ hybrid perovskite (4AMP)­(MA)­Pb 2 I 7 [4AMP is 4-(aminomethyl)­piperidinium, and MA is methylammonium]; moreover, the average Pb–I–Pb bond angle is 174.5° in DJ hybrid perovskite (DGA)­PbI 4 (DGA is dimethylbiguanide), which is larger than the bond angle (150.9°) in RP hybrid perovskite ( o -F-PEA) 2 PbI 4 ( o -F-PEA is ortho -fluoro-phenethylamine).…”