Ar等离子体处理PET在非晶硅太阳电池中的应用

在射频等离子体增强化学气相沉积(RF-PECVD)系统的腔室内,对聚对苯二甲酸乙二醇酯(PET)塑料薄膜进行Ar等离子体预处理,并采用光发射谱(OES)对不同处理参数下的氩气辉光状态进行在线监测。对处理前后PET及PET/ITO进行透过谱、原子力显微镜(AFM)以及扫描电镜(SEM)的测试结果表明,Ar等离子体处理改善了PET塑料薄膜的表面形貌,使之更适合ITO薄膜的生长。以Ar等离子体处理的PET/ITO为衬底,在沉积温度为125℃条件下,制备出效率为5.4%的p-i-n型非晶硅(a-Si)柔性太阳电池。     

Controlled Crystallization of Conjugated Polymer Films from Solution and Solvent Vapor for Polymer Electronics

Over the years, solution‐processable conjugated oligomers and polymers have proven to be very promising for application in organic electronic devices. In addition to tuning the chemical structure of the materials, the role of morphology has been identified as a key parameter in determining device performance. Conjugated polymers are typically semicrystalline in nature consisting of both crystalline and amorphous domains giving rise to a wealth of superstructures. In comparison to classical non‐conjugated semicrystalline polymers, they bear the additional advantage of absorbing light. This makes UV‐vis absorption spectroscopy an excellent tool to monitor polymer aggregation and crystallization in‐situ both in solution and in films. With this feature article we point out the delicate interplay between solution processing and the obtained morphology in polythiophenes and low bandgap copolymers. Subtle changes in the preparation protocol lead to significant changes in textures and also give rise to polymorphism. Solvent vapor annealing and solution crystallization are highlighted as tools to control the nucleation and growth processes in semicrystalline polymer films. Structure‐function relationships between morphological, optical and electronic properties are demonstrated.     

Deciphering the Role of Side-Chain Engineering and Solvent Vapor Annealing for Binary All-Small-Molecule Organic Solar Cells

Fibrous interpenetrating network structure morphology is extremely crucial for all-small-molecule organic solar cells (ASM-OSCs) in achieving high power conversion efficiency (PCE). Rational molecular design and suitable posttreatment to the film are feasible methods to accomplish this goal. Herein, two small molecule donors, namely T4 and T6, with different substituents on their selenophene conjugated units, alkyl for T4 while trialkylsilyl for T6, are developed. Both as cast devices obtain poor PCEs (≈4.5%) when blending these two donors with N3 due to the oversize phase separation. Satisfactorily, the PCEs are dramatically increased after CS₂ annealing, which mainly originates from the favorable reorganization of donor and acceptor in the active layer, ultimately improving the phase separation and vertical electronic properties. As a result, the device based on trialkylsilyl-substituted T6 acquires a remarkable PCE of 16.03%, much higher than that of the blends of alkyl-substituted T4 and N3 (12.61%). The enhanced PCE of the T6-based device is attributed to the deeper HOMO energy levels, more obvious fibrous interpenetrating networks, and stronger molecular interaction between T6 and N3, as compared with T4-based ones. This study indicates that precise molecular design and the proper posttreatment process can be a brilliant approach for realizing highly efficient ASM-OSCs.     

Widely Tunable Morphologies in Block Copolymer Thin Films Through Solvent Vapor Annealing Using Mixtures of Selective Solvents

Thin films of block copolymers are extremely attractive for nanofabrication because of their ability to form uniform and periodic nanoscale structures by microphase separation. One shortcoming of this approach is that to date the design of a desired equilibrium structure requires synthesis of a block copolymer de novo within the corresponding volume ratio of the blocks. In this work, solvent vapor annealing in supported thin films of poly(2‐hydroxyethyl methacrylate)‐block‐poly(methyl methacrylate) [PHEMA‐b‐PMMA] by means of grazing incidence small angle X‐ray scattering (GISAXS) is investigated. A spin‐coated thin film of a lamellar block copolymer is solvent vapor annealed to induce microphase separation and improve the long‐range order of the self‐assembled pattern. Annealing in a mixture of solvent vapors using a controlled volume ratio of solvents, which are chosen to be preferential for each block, enables selective formation of ordered lamellae, gyroid, hexagonal, or spherical morphologies from a single‐block copolymer with a fixed volume fraction. The selected microstructure is then kinetically trapped in the dry film by rapid drying. This paper describes what is thought to be the first reported case where in situ methods are used to study the transition of block copolymer films from one initial disordered morphology to four different ordered morphologies, covering much of the theoretical diblock copolymer phase diagram.     

Precise Structural Development and its Correlation to Function in Conjugated Polymer: Fullerene Thin Films by Controlled Solvent Annealing

The impact of controlled solvent vapor exposure on the morphology, structural evolution, and function of solvent‐processed poly(3‐hexylthiophene):[6,6]‐phenyl‐C₆₁‐butyric acid methyl ester (P3HT:PCBM) bilayers is presented. Grazing incident wide angle X‐ray scattering (GIWAXS) shows that the crystallization of P3HT increases with solvent exposure, while neutron reflectivity shows that P3HT simultaneously diffuses into PCBM, indicating that an initial bilayer structure evolves into a bulk heterojunction structure. Small angle neutron scattering (SANS) shows the agglomeration of PCBM and the formation of a PCBM pure phase when solvent annealing for 90 min. The structural evolution can be described as occurring in two stages: the first stage combines the enhanced crystallization of P3HT and diffusion of PCBM into P3HT, while the second stage entails the agglomeration of PCBM and formation of a PCBM pure phase. The phase separation of PCBM from P3HT is not driven by P3HT crystallinity, but is due to the concentration of PCBM exceeding the miscibility limit of PCBM in P3HT. Correlation of the morphology to photovoltaic activity shows that device performance significantly improves with solvent annealing for 90 min, indicating that both sufficient P3HT crystallization and formation of a PCBM pure phase are crucial in the optimization of the morphology of the active layer.     

Cd气氛退火对CdZnTe晶片质量影响

在CdZnTe晶体生长时,有时会产生大颗粒的沉积相,严重的影响了CdZnTe晶片的质量,通过电子探针测试证明其为Cd沉积相.采用Cd气氛退火来消除Cd沉积相,可以改善CdZnTe晶片的质量.实验发现:在较高的温度(600℃)条件下,退火可以有效的消除大颗粒(＞5 (m)的Cd沉积相,改善CdZnTe晶片红外透过率、X射线双晶回摆曲线半峰宽(FWHM)和腐蚀坑密度(EPD).在此条件下对CdZnTe晶片进行退火,有助于提高CdZnTe晶片的性能.     

Solid-phase Crystallization of Amorphous Silicon Films by Rapid Thermal Annealing

The morphous silicon films prepared by PECVD at substrate temperatures of 30℃ have been crystallized by rapid thermal annealing method, the budget of time-temperature in the annealing process is 600℃ for 120s, 850℃ for 120s, and 950℃ for 120s. The results indicate the crystallization at 850℃ and 950℃ are better as shown in micro-Raman scattering and scanning electronic microscope.     

Tuning the Morphology and Performance of Low Bandgap Polymer:Fullerene Heterojunctions via Solvent Annealing in Selective Solvents

Low bandgap polymer (LBG):fullerene mixtures are some of the most promising organic photovoltaic active layers. Unfortunately, there are no post‐deposition treatments available to rationally improve the morphology and performance of as‐cast LBG:fullerene OPV active layers, where thermal annealing usually fails. Therefore, there is a glaring need to develop post‐deposition methods to guide the morphology of LBG:fullerene bulk heterojunctions towards targeted structures and performance. In this paper, the structural evolution of PCPDTBT:PCBM mixtures with solvent annealing (SA) is examined, focusing on the effect of solvent quality of the fullerene and polymer in the annealing vapor on morphological evolution and device performance. The results indicate that exposure of this active layer to the solvent vapor controls the ordering of PCPDTBT and PCBM phase separation very effectively, presumably by inducing component mobility as the solvent plasticizes the mixture. These results also unexpectedly indicate that solvent annealing in a selective solvent provides a method to invert the morphology of the LBG:fullerene mixture from a polymer aggregate dispersed in a polymer:fullerene matrix to fullerene aggregates dispersed in a polymer:fullerene matrix. The judicious choice of solvent vapor, therefore, provides a unique method to exquisitely control and optimize the morphology of LBG conjugated polymer/fullerene mixtures.     

用金属诱导-准分子激光晶化法制备多晶硅薄膜

提出了一种新的晶化方法——金属诱导-准分子激光晶化法(MI-ELA)。该方法在制备多晶硅(p-Si)薄膜中包括两个步骤：第一步是用镍金属诱导方法(MIC)通过热退火形成NiSi2；第二步是再通过准分子激光退火方法(ELA)晶化形成p-Si。通过用XRD、Raman与SEM测试，研究了p-Si的结晶性和表面形貌特征。研究发现，MI-ELA方法制备的p-Si与传统的ELA方法和MIC方法相比在形貌上不一样，而且从XRD的特征峰强度可以看出在结晶度上有进一步提高。这个结果源于用MIC方法形成的且与e-Si晶格匹配的NiSi2在ELA中起到晶核的作用。这种晶化方法说明，在ELA中，晶粒生长不再仅仅依赖于熔融非晶硅和氧化物表面上残存的随机的固体a-Si作为成核媒介。这种方法不但可以提供晶粒稳定生长条件，而且也可能使获得更大晶粒粒度的激光晶化能量展宽。     

铝诱导晶化法制备多晶硅薄膜

多晶硅薄膜在微电子和能源科学领域有着广泛的应用。本文介绍了利用铝诱导晶化非晶硅制备多晶硅薄膜的方法,叙述了铝诱导晶化法制备多晶硅薄膜的一般过程,着重讨论了铝诱导晶化非晶硅的机理和在制备过程中各种参数对多晶硅薄膜质量的影响。     

铝诱导晶化法制备多晶硅薄膜

多晶硅薄膜在微电子和能源科学领域有着广泛的应用.本文介绍了利用铝诱导晶化非晶硅制备多晶硅薄膜的方法,叙述了铝诱导晶化法制备多晶硅薄膜的一般过程,着重讨论了铝诱导晶化非晶硅的机理和在制备过程中各种参数对多晶硅薄膜质量的影响.