Photoaligned Nanorod Enhancement Films with Polarized Emission for Liquid‐Crystal‐Display Applications

Semiconductor nanorods (NR) emit polarized light, which is expected to bring manifold benefits, in terms of brightness and color enhancement, for modern liquid‐crystal displays (LCD). In this regard, photoaligned nanorod enhancement films (NREF) for color and polarization conversion for LCD backlights are introduced here. The photoinduced anchoring forces, by the photoalignment layer, stimulate well‐ordered self‐assembly of NR in the thin polymer films. Green and red emitting NR with a quantum yield of ≈80% are aligned unidirectionally and in‐plane, showing a polarization ratio of >7:1 and a degree of polarization of >0.81. The photoalignment technique facilitates the fabrication of mixed and multiple stacked NREF for LCDs, which improves the color gamut and polarization efficiency, and is thus expected to increase the optical efficiency of conventional LCDs by ≈60%.     

Recent progress of high performance polymer OLED and OPV materials for organic printed electronics

The development of organic printed electronics has been expanding to a variety of applications and is expected to bring innovations to our future life. Along with this trend, high performance organic materials with cost-efficient fabrication processes and specific features such as thin, light weight, bendable, and low power consumption are required. A variety of organic materials have been investigated in the development of this field. The basic guidelines for material design and the recent progress of polymer-based organic light-emitting diodes (OLEDs) and organic photovoltaic cells (OPVs) are reported.     

High-mobility organic semiconducting crystal for direct X-ray detection

Tissue-equivalent pure organic semiconducting crystals (OSCs) have unique advantages in direct X-ray detectors (DXDs), especially for biological tissue fluoroscopy, but their low carrier mobility and inherent weak absorption restrict the limit-of-detection (LoD) and sensitivity of DXDs. High-mobility OSCs theoretically facilitate charge collection and performance leaps, however, they are rare and suffer from poor solubility due to high conjugation, leading to nearly impossible crystal growth from solution and subsequent device applications. Here we report an ingenious solution-processed crystal-growth and high-performance DXD using 2,6-diphenylanthracene (2,6-DPA), a high-mobility OSC we developed recently. In contrast to previous OSCs, high-mobility 2,6-DPA exhibits low dark current density and large photoconductive gain, resulting in record-breaking LoD of <85 nGy_air s⁻¹ and sensitivity of >10³ μC Gy_air⁻¹ cm⁻². Compared with semiconductors containing high-Z atoms (Z is atomic number), the accuracy of 2,6-DPA based DXDs is not affected by near-edge absorption effects. Moreover, the non-linear relationship between irradiation current and dose rate is confirmed as a high injection effect. High mobility and ingenious crystal growth strategy make 2,6-DPA an ideal active material for DXDs and also provide the possibility for more optoelectronic applications.     

Organic semiconductor-based photonic crystals for solar cell arrays: band gap and optical properties

Photonic crystals (PCs) hold great potential for designing new optical devices because of the possibility of the manipulation of light with PCs. There has been an increase in research on tuning the optical properties of PCs to design devices. We design organic semiconductor-based PC structures and calculate optical properties using the plane wave expansion method and finite-difference time-domain method in an air background for a hexagonal lattice. We showed the possibility of the solar cell arrays for a 2D PC cavity on an organic semiconductor base infiltrated with a nematic liquid crystal. E7 type has been used as a nematic liquid crystal and 4,4′-Bis[4-(diphenylamino) styryl]biphenyl as an organic semiconductor material.     

有机电致发光材料的研发现状

有机电致发光器件 (OLED)具有驱动电压低、主动发光等优势 ,在平板显示领域具有极大的应用前景而引起了广泛的关注。与此同时有机电致发光材料的研发也取得了很大的进展。本文介绍了近年来有机电致发光材料 (包括小分子发光材料和聚合物发光材料 )的研发状况     

聚合物光伏薄膜电池活性材料研究进展

聚合物光伏薄膜电池材料同时具有聚合物(塑料)优异的加工性和无机半导体的导电特性,并具有柔性、质量轻、可进行化学修饰和表现出较高的开路电压(2V)等特性在近年来受到了广泛的关注。文中就聚合物光伏薄膜电池的发展,聚合物薄膜活性材料的特点、分类、发展趋势以及瓶颈进行了概述。     

Rylene and related diimides for organic electronics

Organic electron-transporting materials are essential for the fabrication of organic p-n junctions, photovoltaic cells, n-channel field-effect transistors, and complementary logic circuits. Rylene diimides are a robust, versatile class of polycyclic aromatic electron-transport materials with excellent thermal and oxidative stability, high electron affinities, and, in many cases, high electron mobilities; they are, therefore, promising candidates for a variety of organic electronics applications. In this review, recent developments in the area of high-electron-mobility diimides based on rylenes and related aromatic cores, particularly perylene- and naphthalene-diimide-based small molecules and polymers, for application in high-performance organic field-effect transistors and photovoltaic cells are summarized and analyzed.     

Ternary semitransparent organic solar cells with a laminated top electrode

Abstract

Tinted and colour-neutral semitransparent organic photovoltaic elements are of interest for building-integrated applications in windows, on glass roofs or on facades. We demonstrate a semitransparent organic photovoltaic cell with a dry-laminated top electrode that achieves a uniform average visible transmittance of 51% and a power conversion efficiency of 3%. The photo-active material is based on a majority blend composed of a visibly absorbing donor polymer and a fullerene acceptor, to which a selective near-infrared absorbing cyanine dye is added as a minority component. Our results show that organic ternary blends are attractive for the fabrication of semitransparent solar cells in general, because a guest component with a complementary absorption can compensate for the inevitably reduced current generation capability of a high-performing binary blend when applied as a thin, semitransparent film.     

高分子涂层制备技术研究进展

高分子涂层具有阻隔、耐腐蚀、耐摩擦、防潮湿和绝缘等优点,广泛应用于航空航天、机械等领域.本文综述了高分子涂层的制备,发现其制备方法具有多样性,但多在大气环境中进行,存在高温分解、涂层内应力大和衬底结合力差等问题.对聚酰亚胺薄膜制备研究表明,溶胶-凝胶薄膜存在大量微孔,干燥过程中逸出气体及有机物易产生收缩效应,降低涂层与基底的结合强度;气相沉积聚合法所制薄膜均匀性不易控制,易受挥发溶剂影响;缩聚法对设备要求较高,适于实验室研究.真空喷射法作为一种新方法,可弥补上述不足,具有良好的应用前景,有待进一步研究.     

Development of compact CW-IR laser deposition system for high-throughput growth of organic single crystals

We developed a compact continuous-wave infrared (CW-IR) laser deposition system for the high-throughput growth of organic single crystals. In this system, two CW-IR lasers are used for the sample heating and thermal evaporation of materials. The CW-IR laser heating is simple and allows good control of the deposition rate and growth temperature, in response to the on/off laser switching. Six samples can be loaded simultaneously in a chamber, which allows one-by-one sequential deposition for high-throughput experiments, without breaking the vacuum. Using this setup, we studied the effect of ionic liquids on the growth of C₆₀ crystals in vacuum.     

Development of compact CW-IR laser deposition system for high-throughput growth of organic single crystals

Abstract

We developed a compact continuous-wave infrared (CW-IR) laser deposition system for the high-throughput growth of organic single crystals. In this system, two CW-IR lasers are used for the sample heating and thermal evaporation of materials. The CW-IR laser heating is simple and allows good control of the deposition rate and growth temperature, in response to the on/off laser switching. Six samples can be loaded simultaneously in a chamber, which allows one-by-one sequential deposition for high-throughput experiments, without breaking the vacuum. Using this setup, we studied the effect of ionic liquids on the growth of C₆₀ crystals in vacuum.     

MEH-PPV organic material as saturable absorber for Q-switching and mode-locking applications

ABSTRACT

Q-switched and mode-locked pulse generation in Erbium-doped fiber lasers (EDFLs) are demonstrated using Poly [2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) organic semiconductor material as a saturable absorber (SA) for the first time. The MEH-PPV was prepared in the form of a thin film having a modulation depth of 12% and saturation intensity of 40?MW/cm². The SA was placed in a laser cavity to produce a stable Q-switched operating at 1564.0?nm. The maximum repetition rate of 78.62?kHz, minimum pulse width of 3.54?µs and maximum pulse energy of 59.45?nJ were attained at 125.2?mW pump power. On the other hand, by incorporating an additional 100?m long single mode fiber, the mode locked EDFL self-started as the pump power was raised above 125.2?mW. The soliton pulse was obtained due to the enhancement of the nonlinearity in the cavity. The mode-locked laser operated at 1568.5?nm with a fixed repetition rate of 1.859?MHz and pulse width of 2.97?ps.     

新型酞菁有机半导体材料的制备及气敏性研究

针对无机半导体气体传感器材料可修饰性差、工作温度高等缺点,开展了新型金属酞菁类有机半导体气敏材料的研究,并对敏感材料进行了表征,测试结果与化学结构和理论值一致.采用微电子工艺制备平面叉指电极,采用旋涂技术,在叉指电极上形成敏感膜,对制备的旋涂膜进行红外光谱(IR)和原子力扫描电镜(AFM)表征,AFM图像表明薄膜表面均...     

基于噻吩-苯非对称单元的DPP类聚合物给体材料的合成及光伏性能

为了优化聚合物太阳能电池的光伏性能,设计合成了一种基于噻吩-苯非对称单元的二酮吡咯并[3,4-c]吡咯(DPP)类聚合物给体材料(PDPP-PT)。非对称结构的设计使得该聚合物具有较好的分子堆积,有利于器件的制备。该聚合物具有范围在300~900nm的宽吸收光谱、1.5eV的窄光学带隙。在器件性能方面,活性层厚度达260nm时,测得开路电压(Voc)为0.68V,光电转换效率(PCE)为1.51%。因此,PDPP-PT给体材料在制备厚活性层太阳能电池时具有一定的优势并为聚合物给体材料的分子设计提供了一种新的思路。     

低维纳米光子晶体的制备及在有机激光谐振腔的应用

采用电子束曝光技术以及反应离子刻蚀技术,提出一种简单可控、低成本制备有序排布的一维和二维光子晶体阵列的方法。通过有效的控制刻蚀工艺参数,实现对光子晶体在尺寸、周期和表面结构等进行精确控制目的。此外,以一维光子晶体为衬底,利用甩膜方法成功地制得分布反馈式高分子有机激光器。光泵结果表明,该激光染料的放大自发辐射的阈值为260kW/cm2、半波宽为0.22nm。     

卟啉类光电功能材料的研究进展

卟啉及其衍生物是一类具有优良的光电性能的有机半导体材料．引起人们广泛的关注。本文对卟啉类光电材料在模拟生物光合作用中心的光致电荷转移和能量转移，有机太阳能电池．分子光电器件。有机电致发光和光存储等领域的研究进展做一简要介绍。     

三维表面活性剂-石墨烯复合阴极界面材料在有机太阳能电池中的应用

低沸点绿色溶剂中分散石墨烯可广泛应用于涂料、导电油墨、电池、电子产品和太阳能电池等领域.研究发现,在乙醇溶液中,两种三维阴极界面材料POSSFN和ADMAFN分散石墨烯的浓度可达到0.97–1.18 mg mL^-1,通过计算得知这两种材料在石墨烯表面具有较大的吸附能.通过ESR、Raman、SKPM和XPS等测试手段...     

Nanoantennas for enhanced light trapping in transparent organic solar cells

We propose a light-trapping structure offering a significant enhancement of photovoltaic absorption in transparent organic solar cells operating at infrared, while the visible light transmission keeps sufficiently high. The main mechanism of light trapping is related with the excitation of collective oscillations of the metal nanoantenna arrays, characterized by advantageous field distribution in the volume of the solar cell. It allows more than triple increase in infrared photovoltaic absorption.     

染料敏化太阳能电池的非金属有机敏化剂

染料敏化太阳能电池(DSSC)是一种新型的太阳能电池,综述了DSSC的非金属有机染料敏化剂的研究现状,分析了各类敏化剂的结构与电池的能量转换效率的关系,并提出非金属有机染料结构的设计思路。