High performance organic semiconductor lasers (OSLs), especially those under current injection, have been sought for decades due to their potentially great applications in fields such as spectroscopy, displays, medical devices, and optical interconnection. The design and fabrication of high-quality resonators is a prerequisite for high performance OSLs. In the case of planar microcavities, the fabrication process of top distributed Bragg reflectors (DBRs) usually requires electron beam evaporation or manual lamination on top of organic thin-film layers, which can lead to issues including degradation of the organic materials, large-scale non-uniformity, and difficulties for current injection. Here, we report a non-destructive way of fabricating a top DBR by thermal evaporation. The top DBR based on thermally evaporated alternative TeOx/LiF stacks shows low morphological roughness, high process tolerance, and high reflectivity. Moreover, the deposition process causes negligible damage to the organic thin-film layers underneath. With the combination of a conventional e-beam evaporated bottom DBR, a high performance planar microcavity OSL with a low threshold of 1.7 μJ cm−2, an emission linewidth of 0.24 nm, and an angular divergence of <3° has been achieved under nitrogen laser pumping. Similar performance, with a high Gaussian beam quality comparable with that of an ideal diffraction-limited beam, was also obtained under diode pumping, showing the potential of this technique for building compact and cost-effective organic lasers with good beam quality. Our result will open a promising route for future high performance microcavity optoelectronic devices, especially for laser devices under current injection.

中文翻译：

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基于热蒸发顶部分布布拉格反射器的高性能平面微腔有机半导体激光器

几十年来，人们一直在寻求高性能有机半导体激光器 (OSL)，尤其是那些在电流注入下的激光器，因为它们在光谱学、显示器、医疗设备和光互连等领域具有潜在的巨大应用。高质量谐振器的设计和制造是高性能 OSL 的先决条件。在平面微腔的情况下，顶部分布式布拉格反射器 (DBR) 的制造过程通常需要在有机薄膜层顶部进行电子束蒸发或手动层压，这可能导致包括有机材料降解、大规模电流注入的不均匀性和困难。在这里，我们报告了一种通过热蒸发制造顶部 DBR 的非破坏性方法。基于热蒸发替代 TeOx/LiF 堆栈的顶部 DBR 显示出低形态粗糙度、高工艺公差和高反射率。此外，沉积过程对下面的有机薄膜层造成的损坏可以忽略不计。结合传统的电子束蒸发底部 DBR，在氮气下实现了具有 1.7 μJ cm-2 低阈值、0.24 nm 发射线宽和 <3° 角发散角的高性能平面微腔 OSL激光泵浦。在二极管泵浦下也获得了类似的性能，具有与理想衍射极限光束相当的高高斯光束质量，显示了该技术在构建具有良好光束质量的紧凑且具有成本效益的有机激光器方面的潜力。