卤化银感光材料光作用动力学研究进展

综述了卤化银光作用动力学的研究进展,介绍了微波吸收技术的原理和方法.较详细地介绍了卤化银乳剂加碘、增感剂、稳定剂及其颗粒体积、形状、结构、温度等参数对感光特性(光电子衰减特性)的影响结果.     

The influence of trapping centres on the photoelectron decay in silver halide

Photoelectron is the foundation of latent image formation, the decay process of photoelectrons is influenced by all kinds of trapping centres in silver halide. By analysing the mechanism of latent image formation it is found that electron trap, hole trap, and one kind of recombination centre where free electron and trapped hole recombine are the main trapping centres in silver halide. Different trapping centres have different influences on the photoelectron behaviour. The effects of all kinds of typical trapping centres on the decay of photoelectrons are systematically investigated by solving the photoelectron decay kinetic equations. The results are in agreement with those obtained in the microwave absorption dielectric spectrum experiment.     

纳米硫化镍增感的溴化银微晶中光电子衰减特性研究

利用微弱信号的微波吸收相敏检测技术, 获得了纳米硫化镍增感的立方体溴化银乳剂中, 在增感时间增加的条件下, 自由光电子和浅束缚光电子的时间衰减曲线.分析了采用纳米硫化镍进行增感的溴化银乳剂中光生电子随增感时间衰减的过程, 讨论了卤化银晶体中电子陷阱对光电子运动行为的影响, 分析了电子陷阱效应及陷阱深度同增感时间之间的关系. 通过未增感样品与增感样品的衰减曲线对比, 得到了在此实验条件下的最佳增感时间为80min. 关键词： 纳米硫化镍 衰减时间 电子陷阱 寿命     

采用高传导率银铜镍网格电极的柔性聚合物太阳能电池

采用一种新的阳极材料:银、铜、镍的复合金属网格阳极,利用旋涂法制成了活性层为P3HT (poly(3-hexylthiophene)):PCBM([6,6]-phenylC61-butyricacidmethylester)的柔性衬底聚合物太阳能电池.制备了5种不同结构的柔性聚合物太阳能电池器件,将采用新型阳极材料的柔性衬底聚合物太阳能电池与传统ITO(Indium tin oxide)阳极的柔性衬底聚合物太阳能电池进行对比,发现新型阳极材料所制成的器件性能得到大幅度的提高,其电池器件在50 mW/cm~2强度光照下,开路电压(V_(oc))为0.54 V,短路电流密度(J_(sc))为5.39 mA/cm~2,能量转换效率为2.060%.     

免光学间隔层的高效聚合物太阳能电池

使用相对聚(3乙基噻吩)(P3HT)具有更低能带结构的聚{[9-(1辛基壬基)-9H-咔唑-2,7-2基]-2,5-噻吩二基-2,1,3-苯并噻二唑-4,7-二基-2,5噻吩二基}(PCDTBT)作为电子给体材料和较C60衍生物(PC60BM)具有更广光谱吸收能力的C70衍生物(PC70BM)作为电子受体材料构建共混体系活性层,制备有机聚合物太阳能电池。通过控制活性层薄膜生长速度、环境得出在N2环境中静置10min时聚合物电池达到了5.65%的高光电转换效率(PCE)。然后,通过进一步优化活性层薄膜厚度短路电流密度大幅提升至14.2mA/cm2,PCE达到5.84%。结果表明,在不使用TiOx等光学间隔层的情况下,通过控制活性层薄膜生长过程和优化活性层薄膜厚度也可以大幅增加短路电流密度,获得高的PCE。     

Photoluminescence Mechanism of ZnO：Zn Investigated by Microwave Dielectric Spectrometry

We investigate the decay process of photoelectrons from a luminescent material of ZnO:Zn using a microwave dielectric spectrometry. Electrons in the conduction band are found to decay exponentially and the lifetime is 781 ns, while the time interval of decay from the maximum to half of this value is 470ns. ZnO:Zn is a green luminescent material at its central wavelength of 510 nm. Compared to the decay of electrons in the conduction band, the decay process of the luminescence is faster, and the time interval of decay from the maximum to half of the maximum is about 100 ns. We believe that the mechanism of the ZnO:Zn visible luminescence is recombination luminescence, and find that our theoretical simulation is in agreement with the experimental results.     

掺磷光材料有机电致发光器件的能量传递

将高量子效率的磷光材料fac-tris-2-phenylpyridine iridium(III) (Ir(ppy)3)按不同的比例掺杂到具有载流子传输能力的主体材料poly(N-vinylcarbazole) (PVK)中作为发光层制备磷光电致发光器件。通过对器件发光机制的研究,发现光致发光过程中起主导作用的是Fo¨ster能量转移机制;而在电致发光过程中,器件的发光性能受Dexter能量转移和电荷陷获2种能量传递形式的影响。器件的I-V-L特性表明：Ir(ppy)3的掺杂比例为5%时,器件的光功率效率最大,能量转移最充分。     

卤化银晶体中的光电子特性

本文采用微波吸收相敏检测技术,得到了卤化银微晶的自由光电子与浅束缚光电子的产生与衰减曲线,对比光电子产生量与激发光强之间的关系,验证了Gurney-Mott理论的光吸收过程,分析了不同类型卤化银材料中光电子的衰减特性,讨论了卤化银微晶中光电子行为对其感光性能的影响.     

Investigation of the photoelectron decay of silver halide microcrystal

The microwave absorption dielectric spectrum can be used to study the decay process of free photoelectrons and shallow-trapped electrons in semiconductor crystals. The decay curve of free photoelectrons and shallow-trapped electrons of silver halide grains is measured using this technique. The influence of iodide and K_4Fe(CN)_6 shallow electron trap dopants on the photoelectron lifetime of silver halide grains is studied. For the unsensitized cubic AgCl crystals, when the free photoelectron lifetime (FLT) reaches a maximum, the photographic efficiency is optimal. From our analysis, we conclude that FLT is the longest for the cubic AgCl crystals doped with 0.5% iodide at 80% doping position and 1×10^{-6} mol K_4Fe(CN)_6/molAg, whereas, for the highly photosensitized cubic AgBrCl crystals doped with K_4Fe(CN)_6, the photographic efficiency is optimal when the FLT reaches its minimum. The free photoelectron lifetime reaches minimum and the sensitivity of AgBrCl emulsion reaches maximum when the doping position is 30%Ag at K_4Fe(CN)_6 content of 10^{-6}mol/molAg.     

硫增感AgBrCl立方体微晶中光电子衰减行为的研究

利用微波吸收相敏检测技术并结合短脉冲激光曝光,测量了硫增感条件下AgBrCl立方体微晶感光材料的光电子时间衰减谱.分析了光电子一级衰减区域与增感温度的关系,确定了硫增感的陷阱效应对光电子衰减时间和光电子不同一级衰减区域的影响,并获得了增感过程中生成浅电子陷阱效果的最佳增感条件.