Antisolvent Choice Determines the Domain Distribution of Quasi‐2D Perovskite for Blue‐Emitting Perovskites‐Based Light Emitting Devices

Abstract

Antisolvent treatment is paramount in the fabrication of high-efficiency perovskite optoelectronic devices as it affords a high crystallization rate critical for the formation of pin holes-free perovskite films. Although the antisolvent choice determines the domain distribution of quasi-2D perovskite, and hence the emission wavelength (blue vs green), as well as its light emission efficiency, few studies have examined it in detail. Herein, the crystallization dynamics and resulting optoelectronic properties of PBA (phenyl-butyl-ammonium)-based quasi-2D perovskites (A′ 2 A m-1 Pb m X 3m+1 ), which are commonly employed to create blue emissive films, are scrutinized for the first time through in situ photoluminescence measurements during film formation. The m domain distribution can be tailored by selecting antisolvents with various solubilities of PBA cation. Antisolvents with higher PBA solubility promote the formation of smaller bandgap films due to larger m domains and vice versa. This study effectively reveals a route to tailor quasi-2D perovskite optoelectronic properties via antisolvent engineering. Fine-tuning the optoelectronic properties can be done by blending two antisolvents with contrasting PBA cations solubility. By doing so, a blue emissive light emitting diode with emission wavelength ranging from 471 to 509 nm can be fabricated with an external quantum efficiency of 2.9% at 471 nm.

Temperature Dependence of Charge Transport Properties of Quasi-2D Chiral Perovskite Thin-Film Field-Effect Transistors

“…This provided the basis for making the chiral quasi-2D perovskite thin films with optimal absorption by the two-step antisolvent in situ thin-film formation method. Here, we choose chlorobenzene as the antisolvent to promote the crystallization of the thin films and also render smooth and dense quasi-2D chiral perovskite thin films with a reduced grain size; , the scanning electron microscope (SEM) images of the ( S -, R -MBA) 2 (MA) n −1 Pb n I 3 n +1 thin film illustrated in Figure S2a,b) show a decent uniform film morphology; the thickness of the thin film is around 630 ± 10 nm for two opposite handedness ( S - and R -) samples measured by a Bruker Dektak XT profilometer. To be clear, such thin films consist of many quasi-2D particles randomly stacked upon each other, with the total layer thickness being far greater than the n = 3 particle thickness.…”

Multichromism in Halide Perovskites

“…[63,64] Shifting from 3D perovskite phases to 2D sheets, 1D wires, and 0D isolated octahedra leads to materials exhibiting more distinct energy levels, progressively moving the optical transitions to higher energies, as shown in Figure 2d, which illustrates the transition from 3D to 2D. [31,40,62,65] In low-dimensional perovskites, the t F is relaxed, which allows a large family of spacer cations to be incorporated into the perovskite cage. [66] The relaxation in low di-mensional perovskite arises from its ability to self-regulate the build-up strain via intermolecular bonding when a large organic spacer is introduced.…”

“…Over the last ten years, HPs have garnered significant interest because of their costeffectiveness, multifunctionality, ease of synthesis for highquality films, and exceptional optoelectronic properties. [26][27][28][29][30][31][32] In optoelectronic properties, HPs demonstrated long carrier diffusion length of ≈1 μm, [33,34] bandgap tunability varying from 1 to 3 eV, [35,36] excellent absorption coefficients, [37] narrow emission peaks, and near-unity photoluminescence quantum yields (PLQY). [35,36,38] However, due to their near-zero formation energies, HP materials exhibit polymorphism at room temperature (RT).…”

Silver Ions Assisted Inversion Temperature Crystallization of 2D Cs3Bi2Br9 Nanoflakes for Highly Sensitive X‐Ray Detection

“…[1][2][3][4] This structure-tunable traits of 2D perovskites are beneficial to control their structural distortion, exciton-phonon coupling and quantum confinement, which in turn, attune their electronic and optical properties. [5][6][7][8][9] Nevertheless, most currently 2D perovskites were synthesized by separating compact 3D structure of traditional ABX 3 (A is cation with large radius, B is cation with smaller radius, X is anion) perovskites with organic cation groups, leading to low purity and mixtures of various layered compounds. [10,11] Different from the 2D perovskites composed of organic spacer molecules, allinorganic A 3 B 2 X 9 perovskites were transformed through replacing divalent B with trivalent cations such as Bi 3+ , showing much higher chemical and structure stability to thermal, moisture and oxidation.…”