High-efficiency, solution-processed, multilayer phosphorescent organic light-emitting diodes with a copper thiocyanate hole-injection/hole-transport layer.
High-efficiency, solution-processed, multilayer phosphorescent organic light-emitting diodes with a copper thiocyanate hole-injection/hole-transport layer.
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DOI：
10.1002/adma.201403914
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发表时间：
2015-01-07
影响因子：
29.4
通讯作者：
Bradley, Donal D. C.
中科院分区：
文献类型：
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作者：
Perumal, Ajay;Faber, Hendrik;Yaacobi-Gross, Nir;Pattanasattayavong, Pichaya;Burgess, Claire;Jha, Shrawan;McLachlan, Martyn A.;Stavrinou, Paul N.;Anthopoulos, Thomas D.;Bradley, Donal D. C.
HIL/HTL材料应该理想地结合以下特性：(I)良好的与阳极的粘附性和平坦化，(Ii)在全可见光谱上的高光学透明度，(Iii)允许从典型的阳极材料容易地注入空穴并将这些空穴转移到发射层(EML)的合适功函数，(Iv)足够的导电性以允许低开启和操作电压，(V)良好的电子阻挡性能以防止电子从EML泄漏，和(Vi)良好的激子阻挡性能，以限制EML中的发射态。[5]PEDOT：PSS已成为溶液处理OLED的典型HIL/HTL材料，并将良好的导电性与合理的透明度和功函数相结合。[6]与真空沉积的高效OLED器件HIL/HTL材料一样，[5c]PEDOT：PSS的导电性是通过氧化掺杂实现的。在PEDOT：PSS体系中，PSS链以乙二氧基噻吩氧化聚合(EDOT)为模板，被保留为掺杂(氧化)的PEDOT装饰的反离子支架，促进了溶解性和稳定性。[7A，b]PEDOT：PSS确实有几个限制，特别是它的酸性会损害氧化铟锡(ITO)阳极和EML材料，它的功函数相当低，作为电子阻挡层的效果不是很好，而且它没有很高的热稳定性，特别是在空气中。插入基于芳胺聚合物的薄膜中间层有助于解决其中的一些问题[8]，但在器件制造中增加了两个工艺步骤(层间涂层和高温退火层)。另一种方法是使用无机金属氧化物HIL/HTL，如氧化钨(WO_3)、氧化钼(MoO_3)或氧化镍(NiO)。[4I，9]这些金属氧化物传统上是在高真空下通过热蒸发沉积的，但基于有机-无机杂化前驱体的热分解或包裹在有机增溶/稳定层中的纳米颗粒悬浮液的沉积和退火，正在探索溶液处理的金属氧化层。为了达到适中的导电性和透明性，300℃或等效的激光烧结工艺步骤可能是有害的，尤其是对于塑料基板。[11d]金属氧化物薄膜也可能是相对阻性的，限制它们的使用仅限于薄的(大约几纳米厚)HIL，这可能需要在顶部附加更厚的HTL，再次增加制造步骤。[11，12]在真空沉积小分子和溶液处理的共轭聚合物有机发光二极管(OLED)的早期突破性报道之后，[1]在智能手机、平板电脑和电视显示产品的商业化方面取得了巨大的进展。有机发光二极管照明带来了额外的挑战，包括≈100 lm W-1标准对荧光灯的能效提出了非常严格的要求。真空处理的有机发光二极管最近已经超过了100 lm W-1的目标，[2]从而激发了人们对大面积照明应用的持续兴趣。然而，规模化的真空处理，特别是需要阴影掩膜像素化的情况下，仍然具有挑战性和成本。因此，人们对基于溶液的工艺(如喷墨[3a]或凹版印刷[3b-d]或凹槽模涂覆[3e])表现出强烈且日益增长的兴趣，以解决这些限制，并实现塑料电子在大面积、低成本、高通量器件制造中的最终潜力。用…高效实现溶液处理多层OLED
HIL/HTL materials should ideally combine the following properties:(i) good adhesion to and planarization of the anode,(ii) high optical transparency across the full visible spectrum,(iii) a suitable work function to allow ready injection of holes from typical anode materials and transfer of those holes into the emission layer (EML),(iv) sufficient conductivity to allow low turn-on and operating voltages,(v) good electron-blocking properties to prevent leakage of electrons from the EML, and (vi) good exciton-blocking properties to confine the emissive states within the EML.[5] PEDOT: PSS has been the archetypical HIL/HTL material for solution-processed OLEDs and combines good conductivity with reasonable transparency and work function.[6] As with vacuum-deposited high-efficiency OLED device HIL/HTL materials,[5c] the conductivity of the PEDOT: PSS is achieved by oxidative doping. In the PEDOT: PSS system, PSS chains template the oxidative polymerization of ethylenedioxythiophene (EDOT) and are retained as a counter-ion scaffold that the doped (oxidized) PEDOT decorates and that promotes solubility and stability.[7a, b] PEDOT: PSS does, however, have several limitations, specifically that its acidity can damage indium tin oxide (ITO) anodes and EML materials, its work function is rather low, it is not very effective as an electron-blocking layer, and it does not have high thermal stability, especially in air.[7c, d] Insertion of arylamine polymer based thin film interlayers helps to address some of these issues [8] but unfavorably adds two process steps (interlayer coating and high temperature annealing) to device fabrication. An alternative approach is to use an inorganic metal oxide HIL/HTL such as tungsten oxide (WO 3), molybdenum oxide (MoO 3), or nickel oxide (NiO).[4i, 9] These are traditionally deposited via thermal evaporation under high vacuum [10] but solution-processed metal oxide layers are being explored, based on thermal decomposition of organic–inorganic hybrid precursors or on the deposition and annealing of suspensions of nanoparticles sheathed in organic solubilizing/stabilizing layers.[11] After coating, the metal oxide film normally requires continuous or flash thermal annealing at> 300 C or equivalent laser sintering to reach a moderate conductivity and transparency, processing steps that can be detrimental, especially for plastic substrates.[11d] Metal oxide films can also be relatively resistive restricting their use to that of thin (approximately few nanometer thick) HILs that may then require an additional, thicker, HTL on top, again increasing the fabrication step count.[11, 12]Following early breakthrough reports on vacuum-deposited small molecule and solution-processed conjugated polymer organic light-emitting diodes (OLEDs),[1] tremendous progress has been made in commercializing smartphone, tablet, and television display products. OLED lighting offers additional challenges including very demanding efficiency requirements set by the≈ 100 lm W–1 luminous power efficiency of fluorescent lamps. Vacuum-processed OLEDs have recently passed this 100 lm W–1 target,[2] thereby stimulating continued interest in large area lighting applications. However, vacuum processing at scale, especially where shadow-masked pixellation is required, remains challenging and costly. Strong and growing interest has consequently been shown in solution-based processes (eg ink-jet [3a] or gravure printing [3b–d] or slot-die coating [3e]) to address these limitations and achieve the ultimate potential of plastic electronics in large-area, low-cost, high-throughput device fabrication. Realizing solution-processed multilayer OLEDs with efficiency …
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影响因子：
3.2
作者：
Hoefle, Stefan;Pfaff, Marina;Colsmann, Alexander
通讯作者：
Colsmann, Alexander
影响因子：
29.4
作者：
Hoefle, Stefan;Bruns, Michael;Colsmann, Alexander
通讯作者：
Colsmann, Alexander
用于有机发光二极管的可溶液加工的小分子
影响因子：
--
作者：
Duan, Lian;Hou, Liudong;Qiu, Yong
通讯作者：
Qiu, Yong
影响因子：
--
作者：
Chen, Song;Manders, Jesse R.;So, Franky
通讯作者：
So, Franky
影响因子：
3.3
作者：
Jin, Rui;Levermore, Peter A.;deMello, John C.
通讯作者：
deMello, John C.