Bodipy dyes bearing oligo(ethylene glycol) groups on the meso-phenyl ring: tuneable solid-state photoluminescence and highly efficient OLEDs
Bodipy dyes bearing oligo(ethylene glycol) groups on the meso-phenyl ring: tuneable solid-state photoluminescence and highly efficient OLEDs
复制标题
内消旋苯环上带有低聚乙二醇基团的 Bodipy 染料：可调谐固态光致发光和高效 OLED
DOI：
10.1039/c4tc00720d
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发表时间：
2014-01-01
影响因子：
6.4
通讯作者：
Fu, Wen-Fu
中科院分区：
文献类型：
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作者：
Liu, Cui-Lian;Chen, Yong;Fu, Wen-Fu
具有强固态光致发光特性的硼二吡咯烷（Bodipy）染料在oled中的应用是非常理想的。本研究通过酸催化反应制备了一系列中位-(4-R-C6H4)取代的Bodipy染料(B1为R = H， B2-B5为R （OCH2CH2)(n)OCH2CH3, n = 0-3）。在固体状态下，附着在B2-B5外围的柔性醚基团有望影响分子排列和分子间相互作用。B1-B4的晶体学分析表明，中苯基环几乎与茚二烯平面正交。分子间π - π相互作用在B1中观察到，但在B2-B4中没有。因此，染料B1在固体状态下弱发射，而B2-B4在红色区域强发射，发射量子产率高达0.33。掺入B2的PMMA薄膜呈现出两个分离的发射峰，其相对强度与浓度有关，随着浓度从5 wt%增加到80 wt%，荧光颜色从黄绿色变化到红色。发现基态二聚体的形成是凝聚态红色发射的原因。通过掺杂2 wt%的B2-B4作为发射体制备了高效的oled，其发光效率、电流效率和外量子效率分别高达920 cd m（-2）、8.00 cd A（-1）和2.15%。
Borondipyrromethene (Bodipy) dyes with strong solid-state photoluminescence are highly desirable for their applications in OLEDs. In this work, a series of meso-(4-R-C6H4)-substituted Bodipy dyes (R = H for B1; R (OCH2CH2)(n)OCH2CH3, n = 0-3 for B2-B5, respectively) were prepared through an acid-catalyzed reaction. The flexible ether groups attached to the periphery of B2-B5 are expected to influence the molecular arrangement and intermolecular interactions in solid state. Crystallographic analysis of B1-B4 reveals that the meso-phenyl ring is almost orthogonal to the indacene plane. Intermolecular pi-pi interactions are observed in B1 but absent in B2-B4. As a consequence, the dye B1 is weakly emissive in solid state, while B2-B4 emit strongly in the red region with emission quantum yields of up to 0.33. The PMMA films doped with B2 show two separated emission peaks, and their relative intensity is concentration dependent, leading to the fluorescence color varying from greenish yellow to red as the concentrations successively increased from 5 to 80 wt%. The formation of dimers in the ground state is found to be responsible for the red emission in the condensed state. Efficient OLEDs were fabricated by doping 2 wt% B2-B4 as emitters and gave high luminance, current efficiency, and external quantum efficiency of up to 920 cd m(-2), 8.00 cd A(-1), and 2.15%, respectively.