Organic Nanowire Lasers with Epitaxially Grown Crystals of Semiconducting Oligomers
Organic Nanowire Lasers with Epitaxially Grown Crystals of Semiconducting Oligomers
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DOI：
10.1002/cnma.201700137
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发表时间：
2017-08
期刊：
影响因子：
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通讯作者：
Kazuki Torii;T. Higuchi;K. Mizuno;K. Bando;K. Yamashita;F. Sasaki;H. Yanagi
中科院分区：
文献类型：
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作者：
Kazuki Torii;T. Higuchi;K. Mizuno;K. Bando;K. Yamashita;F. Sasaki;H. Yanagi
分子纳米线是实现电泵浦有机激光器的潜在材料之一。强的光约束在一维腔中的结果在一个低阈值的激发注量轴向法布里-珀罗激光。特别地，分子取向，即各向异性跃迁偶极矩，对增强沿着纳米线轴的受激发射过程起重要作用。从这个角度来看，在这里，我们制备了半导体噻吩/亚苯基共低聚物（TPCOS）的掩模遮蔽沉积在氯化钾（KCl）晶体的解理（001）表面上的外延生长的纳米线。在光泵浦下，未取代的（p型）和氰基取代的（n型）TPCO的单根纳米线都表现出高于>10 uJ/cm 2的阈值能量密度的多模F-P激光，该阈值能量密度随着纳米线长度的增加而降低。它们的分子取向和沿着纳米线轴的堆叠在两个TPCO中适合于有效的光传播与横电模式，从而导致更好的激光性能相比，二维片状晶体的TPCO。
Molecular nanowires are one of potential materials towards realizing electrically pumped organic lasers. Strong light confinement in the one-dimensional cavity results in axial Fabry-Perot lasing at a low threshold of excitation fluence. In particular, the molecular orientation, i.e. anisotropic transition dipole moment, plays an important role to enhance the stimulated emission process along the nanowire axis. From this point of view, here we prepared epitaxially grown nanowires of semiconducting thiophene/phenylene co-oligomers (TPCOs) by mask-shadowing deposition on a cleaved (001) surface of a potassium chloride (KCl) crystal. Under optical pumping, single nanowires of both unsubstituted (p-type) and cyano-substituted (n-type) TPCOs exhibited multimode F-P lasing above a threshold fluence of >10 uJ/cm2 which decreased with increasing nanowire lengths. Their lying molecular orientation and stacking along the nanowire axis in both TPCOs are suitable for effective light propagation with transverse-electric mode resulting in better lasing performances compared to two-dimensional platelet crystals of TPCOs.