Towards Photo-Switchable Transport in Quantum Dot Solids
Towards Photo-Switchable Transport in Quantum Dot Solids
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DOI：
10.1515/zpch-2016-0863
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发表时间：
2016
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影响因子：
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通讯作者：
C. Schedel;Robert Thalwitzer;M. S. Khoshkhoo;Marcus Scheele
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文献类型：
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作者：
C. Schedel;Robert Thalwitzer;M. S. Khoshkhoo;Marcus Scheele
摘要利用光致变色有机半导体1，2-双（5′-羧基-2 ′-甲基噻吩-3 ′-基）-环戊烯（DTCP）交联PbS量子点组装成薄膜。通过振动光谱（FT-IR）和芯能级X射线光电子能谱（XPS）监测配体交换。场效应晶体管（FET）中的输运测量显示出双极特性，空穴和电子迁移率分别为10−4 cm 2/Vs和10−5 cm 2/Vs。暴露于来自4 W UV灯的UV光不会显著改变传输性质，表明在混合膜中DTCP的切换受到阻碍。我们发现一个显着的光电导与快速和可逆的光响应的顺序上的几秒钟，我们归因于（去）填充的量子点陷阱状态。我们的研究结果表明，混合，纳米结构的网络的PbS量子点交联与DTCP可以通过所提出的程序，但开关的量子点结合的DTCP相比，纯的，未绑定的分子物种似乎是受阻。我们将讨论未来解决这一问题的方法。
Abstract We use the photochromic organic semiconductor 1,2-Bis(5′-carboxy-2′-methylthien-3′-yl)-cyclopentene (DTCP) to cross-link PbS quantum dots assembled into thin films. The ligand exchange is monitored by means of vibrational spectroscopy (FT-IR) and core-level X-ray photoemission spectroscopy (XPS). Transport measurements in a field-effect transistor (FET) set-up reveal ambipolar behavior with hole and electron mobilities on the order of 10−4 cm2/Vs and 10−5 cm2/Vs, respectively. Exposure to UV light from a 4 W UV lamp does not significantly change the transport properties, indicating that switching of DTCP is hindered in the hybrid film. We find a pronounced photo-conductance with rapid and reversible photo-response on the order of few seconds, which we attribute to (de-)filling of QD trap states. Our results indicate that hybrid, nanostructured networks of PbS QDs cross-linked with DTCP can be obtained by the presented procedure but that switching of the QD-bound DTCP appears to be hindered compared to the pure, unbound molecular species. We discuss future means to address this problem.