1 太原理工大学物理学院,山西 太原 030024
2 太原理工大学电子信息与光学工程学院,山西 太原 030024
通过在成本较低的活性层P3HT中引入少量在近红外波段有吸光能力的有机受体Y6制成倍增器件,Y6与P3HT发生分子间电荷转移,使得器件的响应波段拓展至1310 nm,在目前所报道的近红外倍增型有机光电探测器中具有明显优势。在空穴传输层与活性层之间引入原子级厚度的Al2O3,极大降低了器件的暗电流,将器件由只能反向偏压响应改善到能够正反双向偏压响应。Al2O3修饰后器件在860 nm处的外量子效率为800%,比探测率为5.6×1011 Jones;1310 nm处器件的外量子效率为80.4%,比探测率为5.13×1010 Jones。
探测器 分子间电荷转移 近红外波段 有机光电倍增探测器 双向偏压 界面修饰
Author Affiliations
Abstract
1 Institute of Materials and Clean Energy, School of Physics and Electronics, Shandong Normal University, Jinan 250014, China
2 State Key Laboratory of Fluid Power and Mechatronic Systems, School of Mechanical Engineering, Zhejiang University, Hangzhou 310030, China
Surface-enhanced Raman scattering (SERS) substrates based on chemical mechanism (CM) have received widespread attentions for the stable and repeatable signal output due to their excellent chemical stability, uniform molecular adsorption and controllable molecular orientation. However, it remains huge challenges to achieve the optimal SERS signal for diverse molecules with different band structures on the same substrate. Herein, we demonstrate a graphene oxide (GO) energy band regulation strategy through ferroelectric polarization to facilitate the charge transfer process for improving SERS activity. The Fermi level (Ef) of GO can be flexibly manipulated by adjusting the ferroelectric polarization direction or the temperature of the ferroelectric substrate. Experimentally, kelvin probe force microscopy (KPFM) is employed to quantitatively analyze the Ef of GO. Theoretically, the density functional theory calculations are also performed to verify the proposed modulation mechanism. Consequently, the SERS response of probe molecules with different band structures (R6G, CV, MB, PNTP) can be improved through polarization direction or temperature changes without the necessity to redesign the SERS substrate. This work provides a novel insight into the SERS substrate design based on CM and is expected to be applied to other two-dimensional materials.
surface-enhanced Raman scattering (SERS) ferroelectric PMN-PT graphene oxide (GO) photo-induced charge transfer (PICT) Opto-Electronic Advances
2023, 6(11): 230094
Author Affiliations
Abstract
1 School of Electronics and Information, Hangzhou Dianzi University, Hangzhou 310018, China
2 Tianjin Key Laboratory of Imaging and Sensing Microelectronic Technology, School of Microelectronics, Tianjin University, Tianjin 300072, China
3 Chongqing Optoelectronics Research Institute, Chongqing 400060, China
CMOS image sensors produced by the existing CMOS manufacturing process usually have difficulty achieving complete charge transfer owing to the introduction of potential barriers or Si/SiO2 interface state traps in the charge transfer path, which reduces the charge transfer efficiency and image quality. Until now, scholars have only considered mechanisms that limit charge transfer from the perspectives of potential barriers and spill back effect under high illumination condition. However, the existing models have thus far ignored the charge transfer limitation due to Si/SiO2 interface state traps in the transfer gate channel, particularly under low illumination. Therefore, this paper proposes, for the first time, an analytical model for quantifying the incomplete charge transfer caused by Si/SiO2 interface state traps in the transfer gate channel under low illumination. This model can predict the variation rules of the number of untransferred charges and charge transfer efficiency when the trap energy level follows Gaussian distribution, exponential distribution and measured distribution. The model was verified with technology computer-aided design simulations, and the results showed that the simulation results exhibit the consistency with the proposed model.
CMOS image sensor charge transfer interface state traps Journal of Semiconductors
2023, 44(11): 114104
1 西安理工大学应用化学系, 西安 710054
2 西安理工大学材料物理与化学系, 西安 710048
3 陕西省微生物研究所, 西安 710043
分别以吡嗪和4,4’-联吡啶为共配体, Cd2+、Zn2+与4,4’-偶氮苯二甲酸(H2(4,4’-azo))配位反应得到了两个金属-有机框架(MOFs)。X射线单晶衍射研究结果表明, 其结构中均不含共配体, 与之前报道的 [Cd(4,4’-azo)(H2O)]n(1)和[Zn(4,4’-azo)(H2O)2]n(2)的晶体结构一致。将共配体变为几何尺寸更长的1,3-二(四吡啶基)丙烷(bpp), 金属离子变为Co2+, 合成了一个共晶[H2(4,4’-azo)(bpp)]n(3), 其为单斜晶系, C2/c空间群, 晶胞参数: a=3.216 8(19) nm, b=0.475 5(3) nm, c=1.873 2(14) nm。用热重分析仪和荧光分光光度计分别研究了三个化合物的热稳定性和两个MOFs的发光性质。1和2都具有优异的热稳定性, 尤其是2的初始失重温度高达247 ℃。由于1是由4,4’-azo双齿配位两个Cd2+形成双核3D网络结构, 而2是4,4’-azo单齿配位Zn2+形成的1D “zig-zag”链, 两者的紫外光谱和荧光光谱不同。2除具有配体固有的荧光发射(359 nm)外, 由于Zn2+与4,4’-azo配位后产生的配体到金属的电荷跃迁(LMCT), 还在420 nm处新增一个增强的荧光发射峰。
4,4’-偶氮苯二甲酸 金属-有机框架 晶体结构 荧光 电荷跃迁 热稳定性 4,4’-azobenzoic acid metal-organic framework crystal structure fluorescence charge transfer thermal stability
1 兰州理工大学 材料科学与工程学院
2 兰州理工大学 理学院,兰州 730050
通过将Liq(8-hydroxyquinolinato-lithium)掺入电子传输层Alq(tris(8-hydroxyquinolinato)aluminum)中,制备了具有不同结构的仅传输电子的单载流子器件。实验结果表明,掺杂器件的电性能劣于含Liq/Al复合阴极的非掺杂器件,优于含Al阴极的非掺杂器件,这表明掺入Alq的Liq没有产生明显的“n型掺杂”效应,其具有双重作用:掺杂后分散在Alq/Al阴极界面上的Liq以电子注入层的形式出现,通过增强电子注入来提高器件电流;掺杂后存在于Alq体相中的Liq由于自身的导电性差,对电子传输具有不利影响,从而降低了器件的电流。在电致发光器件的测试中,Liq的掺杂表现出类似的现象,掺入Liq的器件性能介于非掺杂具有Liq/Al阴极和Al阴极结构器件之间,三种器件的最大电流效率分别为3.96,4.27和2.27 cd/A,并且在吸收光谱和光致发光光谱中观察不到电荷转移所带来的额外变化。
有机半导体 界面修饰 电荷转移 organic semiconductor Liq Liq Alq Alq interface modification charge transfer
苏州大学材料与化学化工学部, 江苏 苏州 215123
载流子在等离激元金属纳米粒子上的快速复合, 导致传统的光电催化剂效率显著降低, 通过金属和半导体的复合可实现热电子和空穴的分离以提升光电催化效率。 采用Ag纳米粒子与半导体TiO2纳米粒子复合提高其光电催化活性, 并探索了催化活性提升的机理, 研究了TiO2-Ag纳米复合材料之间空间电荷区能带弯曲以及内置电场的作用, 为设计高性能SPR光电催化剂提供理论和实验依据。 以对氨基苯硫酚(PATP)及对硝基苯硫酚(PNTP)的光电催化偶联反应为探针, 研究了TiO2-Ag纳米复合材料的催化性能。 结果表明TiO2的引入提高了Ag的SPR催化活性, 其主要原因是TiO2的引入可提高TiO2-Ag间电子和空穴的分离效率。
表面增强拉曼光谱 电荷转移 肖特基势垒 表面等离激元共振催化 Surface enhanced Raman spectroscopy TiO2-Ag TiO2-Ag nanocomposites Charge transfer Schottky barrier SPR catalysis 光谱学与光谱分析
2023, 43(4): 1112