The purpose of this paper is to review the research progress in the realization of the organic–inorganic hybrid thin-film packaging of flexible organic electroluminescent devices using the PEALD (plasma-enhanced atomic layer deposition) and MLD (molecular layer deposition) techniques. Firstly, the importance and application prospect of organic electroluminescent devices in the field of flexible electronics are introduced. Subsequently, the principles, characteristics and applications of PEALD and MLD technologies in device packaging are described in detail. Then, the methods and process optimization strategies for the preparation of organic–inorganic hybrid thin-film encapsulation layers using PEALD and MLD technologies are reviewed. Further, the research results on the encapsulation effect, stability and reliability of organic–inorganic hybrid thin-film encapsulation layers in flexible organic electroluminescent devices are discussed. Finally, the current research progress is summarized, and the future research directions and development trends are prospected.

White organic light-emitting diodes (WOLEDs) hold vast prospects in the fields of next-generation displays and solid-state lighting. Ultrathin emitting layers (UEMLs) have become a research hotspot because of their unique advantage. On the basis of simplifying the device structure and preparation process, they can achieve electroluminescent performance comparable to that of doped devices. In this review, we first discuss the working principles and advantages of WOLEDs based on UEML architecture, which can achieve low cost and more flexibility by simplifying the device structure and preparation process. Subsequently, the successful applications of doping and non-doping technologies in fluorescent, phosphorescent, and hybrid WOLEDs combined with UEMLs are discussed, and the operation mechanisms of these WOLEDs are emphasized briefly. We firmly believe that this article will bring new hope for the development of UEML-based WOLEDs in the future.

The performance and stability of perovskite solar cells (PSCs) are critically influenced by the interfacial properties between the perovskite absorption layer and the electron transport layer (ETL). This study introduces a novel interfacial engineering approach using dipotassium 7-hydroxynaphthalene-1,3-disulfonate (K-NDS) as a multifunctional passivator to enhance both the SnO₂ ETL and the perovskite absorber layer. The sulfonic acid groups (–SO₃ ⁻) in K-NDS effectively fill oxygen vacancies on the SnO₂ surface, while the hydroxyl groups (–OH) passivate dangling bonds, improving the crystallinity of the perovskite film. Additionally, the diffusion of K⁺ from the SnO₂ ETL into the perovskite layer optimizes energy level alignment, thereby enhancing charge carrier extraction and transport. This bifacial passivation strategy has significantly improved both the power conversion efficiency (PCE) and long-term stability of PSCs. The modified devices achieved a champion PCE of 23.00% and an open-circuit voltage (V_OC) of 1.172 V. Furthermore, these devices maintained 75% of their initial PCE even after 1000 hours of storage under indoor environmental conditions. This work demonstrates the effectiveness of synergistic interfacial passivation in advancing the performance and durability of PSCs.

Tungsten oxide (WO₃) electrochromic devices are obtaining increasing interest due to their color change and thermal regulation. However, most previous work focuses on the absorption or transmission spectra of materials, rather than the optical parameters evolution in full spectrum in the electrochromic processes. Herein, we developed a systematic protocol of ex situ methods to clarify the evolutions of subtle structure changes, Raman vibration modes, and optical parameters of WO₃ thin films in electrochromic processes as stimulated by dosage-dependent Li⁺ insertion. We obtained the below information by ex situ spectroscopic ellipsometry. (1) Layer-by-layer Li⁺ embedding mechanism demonstrated by individual film thickness analysis. (2) The details of its optical leap in the Brillouin zone in the full spectral. (3) The optical constants varied with the Li⁺ insertion in the ultraviolet, visible, and near-infrared bands, demonstrating the potential for applications in chip fabrication, deep-sea exploration, and optical measurements. (4) Simulated angular modulation laws of WO₃ films for full spectra in different Li⁺ insertion states. This ex situ method to study the optical properties of electrochromic devices are important for monitoring phase transition kinetics, the analysis of optical leaps, and the study of ion diffusion mechanisms and the stoichiometry-dependent changes in optical constants over the full spectral. This work shows that electrochromic films in Li⁺ surface permeation can be applied in the field of zoom lenses, optical phase modulators, and other precision optical components. Our work provides a new solution for the development of zoom lenses and a new application scenario for the application of electrochromic devices.

Blue exciplexes, a critical innovative component in organic light-emitting diodes (OLEDs) technology, exhibit substantial potential for enhancing device efficiency, reducing driving voltage, and simplifying structural designs. This article reviews the pivotal role of blue exciplexes in OLEDs, analyzing their unique advantages and challenges as emitters and host materials. Through optimized molecular design, blue exciplexes achieve high color purity and emission efficiency, surpassing conventional fluorescent materials. Additionally, their wide energy bands and high triplet energy provide opportunities to improve the performance of sky-blue, deep-blue, and white OLEDs. However, limitations in deep-blue efficiency, material degradation due to high-energy excitons, and spectral red-shift pose significant challenges to their development. This review offers a comprehensive perspective and research reference on the photophysical mechanisms of blue exciplexes and their applications in display and lighting fields.