Shufen Chen

Bio: Shufen Chen is an academic researcher from Nanjing University of Posts and Telecommunications. The author has contributed to research in topics: OLED & Perovskite (structure). The author has an hindex of 20, co-authored 97 publications receiving 1812 citations. Previous affiliations of Shufen Chen include Nanjing University & Nanyang Technological University.

Recent Developments in Top‐Emitting Organic Light‐Emitting Diodes

Abstract: Organic light-emitting diodes (OLEDs) have rapidly progressed in recent years due to their unique characteristics and potential applications in flat panel displays. Significant advancements in top-emitting OLEDs have driven the development of large-size screens and microdisplays with high resolution and large aperture ratio. After a brief introduction to the architecture and types of top-emitting OLEDs, the microcavity theory typically used in top-emitting OLEDs is described in detail here. Then, methods for producing and understanding monochromatic (red, green, and blue) and white top-emitting OLEDs are summarized and discussed. Finally, the status of display development based on top-emitting OLEDs is briefly addressed.

Lead-Free Perovskite Materials for Solar Cells

Abstract: The toxicity issue of lead hinders large-scale commercial production and photovoltaic field application of lead halide perovskites. Some novel non- or low-toxic perovskite materials have been explored for development of environmentally friendly lead-free perovskite solar cells (PSCs). This review studies the substitution of equivalent/heterovalent metals for Pb based on first-principles calculation, summarizes the theoretical basis of lead-free perovskites, and screens out some promising lead-free candidates with suitable bandgap, optical, and electrical properties. Then, it reports notable achievements for the experimental studies of lead-free perovskites to date, including the crystal structure and material bandgap for all of lead-free materials and photovoltaic performance and stability for corresponding devices. The review finally discusses challenges facing the successful development and commercialization of lead-free PSCs and predicts the prospect of lead-free PSCs in the future.

Multilayer Stacked Low‐Temperature‐Reduced Graphene Oxide Films: Preparation, Characterization, and Application in Polymer Memory Devices

Abstract: Highly reduced graphene oxide (rGO) films are fabricated by combining reduction with smeared hydrazine at low temperature (e.g., 100 degrees C) and the multilayer stacking technique. The prepared rGO film, which has a lower sheet resistance ( approximately 160-500 Omega sq(-1)) and higher conductivity (26 S cm(-1)) as compared to other rGO films obtained by commonly used chemical reduction methods, is fully characterized. The effective reduction can be attributed to the large "effective reduction depth" in the GO films (1.46 microm) and the high C1s/O1s ratio (8.04). By using the above approach, rGO films with a tunable thickness and sheet resistance are achieved. The obtained rGO films are used as electrodes in polymer memory devices, in a configuration of rGO/poly(3-hexylthiophene) (P3HT):phenyl-C61-butyric acid methyl ester (PCBM)/Al, which exhibit an excellent write-once-read-many-times effect and a high ON/OFF current ratio of 10(6).

A small change in molecular structure, a big difference in the AIEE mechanism

Abstract: An anthracene carboxamide derivative of the excited-state intramolecular proton-transfer compound of 2-(2′-hydroxyphenyl)benzothiazole has been newly developed to produce the prominent characteristics of aggregation-induced enhanced emission (AIEE) with a high solid-state fluorescence quantum efficiency of 78.1%. Compared with our previously reported phenyl carboxamide derivatives, a small tailoring of the molecular structure was found to result in a big difference in the dominant factor of the AIEE mechanism. In the phenyl carboxamide derivatives, the dominant factor of the AIEE mechanism is the restriction of the twisted intramolecular charge transfer (TICT) of the enol excited state, regardless of their different aggregation modes. In the anthracene carboxamide derivative, N-(3-(benzo[d]thiazol-2-yl)-4-hydroxyphenyl) anthracene-9-carboxamide, the AIEE characteristics are not dependent on the restriction of TICT, but mainly attributed to the cooperative effects of J-aggregation and the restriction of the cis–trans tautomerization in the keto excited state. A specific N⋯π interaction was found to be the main driving force for this J-aggregation, as revealed by the single crystal analysis. The AIEE mechanism of this anthracene carboxamide derivative was studied in detail through photophysical investigations and theoretical calculations. On the basis of its AIEE characteristics, a stable non-doped organic light-emitting diode was achieved, with high color purity and a remarkably low efficiency roll-off.

Recent Advances in Ultrathin Two-Dimensional Nanomaterials

Abstract: Since the discovery of mechanically exfoliated graphene in 2004, research on ultrathin two-dimensional (2D) nanomaterials has grown exponentially in the fields of condensed matter physics, material science, chemistry, and nanotechnology. Highlighting their compelling physical, chemical, electronic, and optical properties, as well as their various potential applications, in this Review, we summarize the state-of-art progress on the ultrathin 2D nanomaterials with a particular emphasis on their recent advances. First, we introduce the unique advances on ultrathin 2D nanomaterials, followed by the description of their composition and crystal structures. The assortments of their synthetic methods are then summarized, including insights on their advantages and limitations, alongside some recommendations on suitable characterization techniques. We also discuss in detail the utilization of these ultrathin 2D nanomaterials for wide ranges of potential applications among the electronics/optoelectronics, electrocat...

Graphene-based composites

Abstract: Graphene has attracted tremendous research interest in recent years, owing to its exceptional properties. The scaled-up and reliable production of graphene derivatives, such as graphene oxide (GO) and reduced graphene oxide (rGO), offers a wide range of possibilities to synthesize graphene-based functional materials for various applications. This critical review presents and discusses the current development of graphene-based composites. After introduction of the synthesis methods for graphene and its derivatives as well as their properties, we focus on the description of various methods to synthesize graphene-based composites, especially those with functional polymers and inorganic nanostructures. Particular emphasis is placed on strategies for the optimization of composite properties. Lastly, the advantages of graphene-based composites in applications such as the Li-ion batteries, supercapacitors, fuel cells, photovoltaic devices, photocatalysis, as well as Raman enhancement are described (279 references).

Graphene-Based Materials: Synthesis, Characterization, Properties, and Applications

Abstract: Graphene, a two-dimensional, single-layer sheet of sp(2) hybridized carbon atoms, has attracted tremendous attention and research interest, owing to its exceptional physical properties, such as high electronic conductivity, good thermal stability, and excellent mechanical strength. Other forms of graphene-related materials, including graphene oxide, reduced graphene oxide, and exfoliated graphite, have been reliably produced in large scale. The promising properties together with the ease of processibility and functionalization make graphene-based materials ideal candidates for incorporation into a variety of functional materials. Importantly, graphene and its derivatives have been explored in a wide range of applications, such as electronic and photonic devices, clean energy, and sensors. In this review, after a general introduction to graphene and its derivatives, the synthesis, characterization, properties, and applications of graphene-based materials are discussed.

Recent progress in metal–organic complexes for optoelectronic applications

Abstract: The design and characterization of metal–organic complexes for optoelectronic applications is an active area of research. The metal–organic complex offers unique optical and electronic properties arising from the interplay between the inorganic metal and the organic ligand. The ability to modify chemical structure through control over metal–ligand interaction on a molecular level could directly impact the properties of the complex. When deposited in thin film form, this class of materials enable the fabrication of a wide variety of low-cost electronic and optoelectronic devices. These include light emitting diodes, solar cells, photodetectors, field-effect transistors as well as chemical and biological sensors. Here we present an overview of recent development in metal–organic complexes with controlled molecular structures and tunable properties. Advances in extending the control of molecular structures to solid materials for energy conversion and information technology applications will be highlighted.