Realizing Highly Stable Quasi-2D Blue Perovskite Light-Emitting Diodes Using Energy Cascades Generated by Biomolecule-Derived Plasmonic Nanostructures.

Blue perovskite light-emitting diodes (LEDs) lag behind green and red LEDs, which have made considerable strides in efficiency and stability. The main disadvantage is its unmodulated phase domains and low energy transfer efficiency, which impede the efficiency, optical purity, and operational stability of the devices. Herein, we show that using biomolecule-derived plasmonic nanostructures can significantly promote defect passivation, van der Waals gap reduction, and cascade energy transfer through synergistic small-molecule interactions and localized surface plasmonic contributions, thereby improving the electroluminescence (EL) properties and operational stability.

Enhancing the Performance of 2D Tin-Based Pure Red Perovskite Light-Emitting Diodes through the Synergistic Effect of Natural Antioxidants and Cyclic Molecular Additives.

Tin (Sn)-based perovskites are being investigated in many optoelectronic applications given their similar valence electron configuration to that of lead-based perovskites and the potential environmental hazards of lead-based perovskites. However, the formation of high-quality Sn-based perovskite films faces several challenges, mainly due to the easy oxidation of Sn to Sn and the fast crystallization rate. Here, to develop an environmentally friendly process for Sn-based perovskite fabrication, a series of natural antioxidants are studied as additives and ascorbic acid (VitC) is found to have a superior ability to inhibit the oxidation problem.

Realizing High Brightness Quasi-2D Perovskite Light-Emitting Diodes with Reduced Efficiency Roll-Off via Multifunctional Interface Engineering.

Quasi-2D perovskites have recently flourished in the field of luminescence due to the quantum-confinement effect and the efficient energy transfer between different n phases resulting in exceptional optical properties. However, owing to the lower conductivity and poor charge injection, quasi-2D perovskite light-emitting diodes (PeLEDs) typically suffer from low brightness and high-efficiency roll-off at high current densities compared to 3D perovskite-based PeLEDs, which is undoubtedly one of the most critical issues in this field. In this work, quasi-2D PeLEDs with high brightness, reduced trap density, and low-efficiency roll-off are successfully demonstrated by introducing a thin layer of conductive phosphine oxide at the perovskite/electron transport layer interface.

Performance Enhancement of Lead-Free 2D Tin Halide Perovskite Transistors by Surface Passivation and Its Impact on Non-Volatile Photomemory Characteristics.

Two-dimensional (2D) tin (Sn)-based perovskites have recently received increasing research attention for perovskite transistor application. Although some progress is made, Sn-based perovskites have long suffered from easy oxidation from Sn to Sn , leading to undesirable p-doping and instability. In this study, it is demonstrated that surface passivation by phenethylammonium iodide (PEAI) and 4-fluorophenethylammonium iodide (FPEAI) effectively passivates surface defects in 2D phenethylammonium tin iodide (PEA SnI ) films, increases the grain size by surface recrystallization, and p-dopes the PEA SnI film to form a better energy-level alignment with the electrodes and promote charge transport properties.

Regulating the phase distribution of quasi-2D perovskites using a three-dimensional cyclic molecule toward improved light-emitting performance.

In this study, a molecule with a three-dimensional (3D) cyclic structure, a cryptand, is demonstrated as an effective additive for the quasi-two-dimensional (quasi-2D) PEACsPbBr ( = 3, herein) to improve its light-emitting performance. The cryptand can effectively regulate the phase distribution of the quasi-2D perovskite through its intense interaction with PbBr, benefitting from its cage-like structure that can better capture the Pb ions. Due to the inhibited growth of the low- phases, a much-concentrated phase distribution is achieved for the cryptand-containing films.

Enhancing the Performance of Quasi-2D Perovskite Light-Emitting Diodes Using Natural Cyclic Molecules with Distinct Phase Regulation Behaviors.

In this study, two natural small molecules, α-cyclodextrin (α-CD) and β-cyclodextrin (β-CD), are used as additives to improve the performance of quasi-2D PEACsPbBr ( = 3, herein) PeLEDs. Both of them are shown to efficiently passivate the quasi-2D perovskite films to afford improved film quality and morphology, but they exhibit distinct phase regulation behaviors possibly due to their different pore sizes. It reveals that α-CD effectively suppresses the formation of the low- phases ( ≤ 2), while β-CD better regulates the phase with a medium- value ( = 3).

Inorganic-Cation Pseudohalide 2D Cs Pb(SCN) Br Perovskite Single Crystal.

Most of the reported 2D Ruddlesden-Popper (RP) lead halide perovskites with the general formula of A B X (n = 1, 2, …) comprise layered perovskites separated by A-site-substituted organic spacers. To date, only a small number of X-site-substituted RP perovskites have been reported. Herein, the first inorganic-cation pseudohalide 2D phase perovskite single crystal, Cs Pb(SCN) Br , is reported.

Two-Dimensional CsPb(SCN)Br-Based Photomemory Devices Showing a Photoinduced Recovery Behavior and an Unusual Fully Optically Driven Memory Behavior.

The rapid development of Internet of Things and big data has made the conventional storage devices face the need of reforming. Rather than using electrical pulses to store data in one of two states, photomemory exploiting optical stimulation to store light information emerges as a revolutionary candidate for the optoelectronic community. However, fully optically driven photomemory with fast data transmission speed and outstanding energy saving capability suffers from less exploration.