Mitigating Detrimental Effect of Self-Doping Near the Anode in Highly Efficient Organic Solar Cells

Poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) has been one of the most established hole transport layers (HTL) in organic solar cells (OSCs) for several decades. However, the presence of PSS⁻ ions is known to deteriorate device performance via a number of mechanisms including diffusion to the HTL-active layer interface and unwanted local chemical reactions. In this study, it is shown that PSS⁻ ions can also result in local p-doping in the high efficiency donor:non-fullerene acceptor blends – resulting in photocurrent loss. To address these issues, a facile and effective approach is reported to improve the OSC performance through a two-component hole transport layer (HTL) consisting of a self-assembled monolayer of 2PACz ([2-(9H-Carbazol-9-yl)ethyl]phosphonic acid) and PEDOT:PSS. The power conversion efficiency (PCE) of 17.1% using devices with PEDOT:PSS HTL improved to 17.7% when the PEDOT:PSS/2PACz two-component HTL is used. The improved performance is attributed to the overlaid 2PACz layer preventing the formation of an intermixed p-doped PSS⁻ ion rich region (≈5–10 nm) at the bulk heterojunction-HTL contact interface, resulting in decreased recombination losses and improved stability. Moreover, the 2PACz monolayer is also found to reduce electrical shunts that ultimately yield improved performance in large area devices with PCE enhanced from 12.3% to 13.3% in 1 cm² cells.     

1.55 μm DFB LD光栅结构的优化设计

模拟分析了不同结构下二级光栅的特性,研究了光栅结构对分布分馈半导体激光器(DFB LD)空间烧孔以及光谱线宽的影响.最终给出优化后的光栅结构.优化后器件的阈值电流为11 mA,边模抑制比达到40 dB,最小线宽105 kHz,很好地抑制了空间烧孔效应.     

Investigation of pattern coating on mould roller in roller-reversal imprint process

In order to prepare large area micropatterns with certain profile (certain aspect ratio) on kinds of substrates, especially on flexible substrate, a novel roller-reversal imprint (RRI) process is proposed, which starts with pattern coating of an ink (mostly a liquefied electronics materials, such as a semiconductor polymer) on a mould roller and ends with transferring the ink already patterned on the roller to the substrate. One of the critical challenges in RRI process is ensuring ink pattern coating and full filling to the microcavities on mould roller, which is one of the preconditions to achieve the pattern transferred on substrate with precise profile. In this paper, an ink coating model is established to reveal the ink filling situations versus different profile of microcavities on mould roller. Simulations show that, in the coating process, as the contact angle of ink on mould increasing, three basic filling situations, i.e., full filling, partial filling, and non-filling, will occur. In order to demonstrate the requirement of full filling, critical contact angle for full filling is proposed to distinguish the full filling and partial filling, and it is deeply dependant on the cross-sectional parameters (such as linewidth and the aspect ratio) of microcavities on mould roller. The critical contact angle is the watershed between full filling and partial filling, so it can be used as a guideline to choose the appropriate match between the surface energy of ink and mould to achieve full filling in RRI process. Experiments prove that the ink filling model and its simulation results are basically right, the cross-sectional parameters of microcavities on mould play great important roles to the critical contact angle, and only when the actual contact angle is smaller than the corresponding critical value, full filling can be obtained.     

刚挠印制板镀覆孔孔壁开裂原因分析

为适应电子产品的发展,刚挠印制板的应用范围越来越大,用户对刚挠板性能的要求越来越高.概述了刚挠印制板镀覆孔孔壁发生开裂的原因,从基材、钻孔、孔金属化前处理和化学镀铜等角度分析并解决镀覆孔开裂问题.     

基于动态阿贝原则的高精度激光深孔孔径测量

基于动态阿贝原则提出了激光深孔孔径测量原理,设计了一种利用双频激光干涉技术的深孔孔径超精密测量系统。该系统将双频激光干涉测长技术与超精密双向电容位移传感器瞄准方法有机结合在一起,通过电容位移传感瞄准、测长光路和深度位置监测光路的合理设计,保证了在深孔任意截面对孔径的测量都符合阿贝原则。分别用Ф5～Ф16mm6种环规对系统进行验证。实验表明,该系统可实现深孔任意截面孔径的高精度测量,测量分辨力达10nm,不确定度达0.1μm。     

HDI板RCC料层孔壁爆裂原因分析和改善

分析了HDI板生产中RCC料层出现孔壁爆裂的原因,同时给出了改善方法,并对此原因和改善方法进行了验证。     

基于改进型神经网络的软测量模型的建立与应用

使用改进的RBF(径向基函数)神经网络(即小波神经网络)来建模,并采用改进算法确定其隐含层节点的各个参数,然后以一个充填搅拌生产过程中的料浆浓度为研究对象,建立其软测量模型,并通过仿真实验验证了该方案的可行性。该方案充分利用了软测量的优点及神经网络的强分类能力,为沙浆浓度的测量提出了优良的方法,从而可以保证整个充填系统的可靠运行。该测量模型应用范围很广,可以对工业生产中的一些重要的工艺参数如矿浆、煤浆、混沙浆、纸浆等进行精确测量。     

Temperature-dependent ambipolar electrical characteristics of pentacene-based thin-film transistors: The impact of opposite-sign charge carriers

The temperature-dependent electrical and charge transport characteristics of pentacene-based ambipolar thin-film transistors (TFTs) were investigated at temperatures ranging from 77 K to 300 K. At room temperature (RT), the pentacene-based TFTs exhibit balanced and high charge mobility with electron (μ_e) and hole (μ_h) mobilities, both at about 1.6 cm²/V s. However, at lower temperatures, higher switch-on voltage of n-channel operations, almost absent n-channel characteristics, and strong temperature dependence of μ_e indicated that electrons were more difficult to release from opposite-signed carriers than that of holes. We observed that μ_e and μ_h both followed an Arrhenius-type temperature dependence and exhibited two regimes with a transition temperature at approximately 210–230 K. At high temperatures, data were explained by a model in which charge transport was limited by a dual-carrier release and recombination process, which is an electric field-assisted thermal-activated procedure. At T < 210 K, the observed activation energy is in agreement with unipolar pentacene-based TFTs, suggesting a common multiple trapping and release process-dominated mechanism. Different temperature-induced characteristics between n- and p-channel operations are outlined, thereby providing important insights into the complexity of observing efficient electron transport in comparison with the hole of ambipolar TFTs.     

高速深孔加工顶紧系统设计分析

在高速深孔加工中,其中影响加工可靠性的重要因素就是工件以及受油器,在不同的高速深孔加工过程中,对连接工件以及受油器的顶紧力的要求也是不一样的,对顶紧力的精度有着更高的要求.本文就高速深孔加工顶紧系统设计进行具体地分析,进而使该技术得到更好地应用.     

填充介质对火药装药爆轰性能的影响

为了研究火药颗粒在不同介质中的爆轰性能,在火药颗粒空隙中分别均匀填充水、氧化剂溶液、氧化剂凝胶,通过板痕试验及测时仪法研究了不同填充物对火药装药爆轰性能的影响,并与无填充物的装药进行了对比;测试了灌注液的氧平衡对火药装药水下爆炸能量的影响。结果表明,水、氧化剂溶液、氧化剂凝胶等密实介质的加入,有利于爆轰冲击波的成长及传播,装药的爆速逐渐增加。火药颗粒装药中填充含氧化剂的密实介质后,能稳定爆轰并具有良好的爆轰性能,爆速6.4 km·s~(-1)。随着氧平衡的提高,火药装药的水下爆炸能量逐渐增加,总比能量与其氧平衡存在显著的线性关系。与岩石乳化炸药、铵油炸药相比,含火药装药的比冲击波能较高,其值大于1.0 kJ·g~(-1),总比能基本相当。