Trion Electroluminescence from Semiconducting Carbon Nanotubes
Trion Electroluminescence from Semiconducting Carbon Nanotubes
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DOI：
10.1021/nn503046y
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发表时间：
2014-08-01
期刊：
影响因子：
17.1
通讯作者：
Zaumseil, Jana
中科院分区：
文献类型：
--
作者：
Jakubka, Florian;Grimm, Stefan B.;Zaumseil, Jana
半导体单壁碳纳米管（SWNTs）的近红外发射通常是激子辐射弛豫的结果。通过化学或电化学掺杂结合额外的电子或空穴，产生了带电的三体激子，即所谓的trion，它们在较低的能量下发光。能量差足够大，即使在室温下也可以观察到掺杂单壁碳纳米管的弱三电子光致发光。在这里，我们展示了来自电解质门控的、具有三种不同聚合物分选的碳纳米管物种（即，（6，5）、（75）和（10，5））的发光SWNT晶体管的强三电子电致发光。由于晶体管沟道中载流子密度较高，导致了红移的三电子发射与激子发射相当甚至更强。讨论了三重态和暗激子通过电子-空穴复合而大量形成的三重态作为辐射弛豫途径的可能性。激子发射与激子发射的比率可以通过施加的电压来调节，使得能够实现具有窄线宽的电压控制的近红外光源，其是溶液可处理的并且在低电压（
Near-infrared emission from semiconducting single-walled carbon nanotubes (SWNTs) usually results from radiative relaxation of excitons. By binding an additional electron or hole through chemical or electrochemical doping, charged three-body excitons, so-called trions, are created that emit light at lower energies. The energy difference is large enough to observe weak trion photoluminescence from doped SWNTs even at room temperature. Here, we demonstrate strong trion electroluminescence from electrolyte-gated, light-emitting SWNT transistors with three different polymer sorted carbon nanotube species, namely, (6,5), (75) and (10,5). The red-shifted trion emission is equal to or even stronger than the exciton emission, which is attributed to the high charge carrier density in the transistor channel. The possibility of trions as a radiative relaxation pathway for triplets and dark excitons that are formed in large numbers by electron-hole recombination is discussed. The ratio of trion to exciton emission can be tuned by the applied voltages, enabling voltage-controlled near-infrared light sources with narrow line widths that are solution-processable and operate at low voltages (