Banerjee Sreetama, Bülz Daniel, Reuter Danny, Hiller Karla, Zahn Dietrich R T, Salvan Georgeta
Semiconductor Physics, Technische Universität Chemnitz, Germany.
Center for Microtechnologies, Technische Universität Chemnitz, Germany.
Beilstein J Nanotechnol. 2017 Jul 21;8:1502-1507. doi: 10.3762/bjnano.8.150. eCollection 2017.
We report light-induced negative organic magnetoresistance (OMAR) measured in ambient atmosphere in solution-processed 6,13-bis(triisopropylsilylethynyl)pentacene (TIPS-pentacene) planar hybrid devices with two different device architectures. Hybrid electronic devices with trench-isolated electrodes (HED-TIE) having a channel length of ca. 100 nm fabricated in this work and, for comparison, commercially available pre-structured organic field-effect transistor (OFET) substrates with a channel length of 20 µm were used. The magnitude of the photocurrent as well as the magnetoresistance was found to be higher for the HED-TIE devices because of the much smaller channel length of these devices compared to the OFETs. We attribute the observed light-induced negative magnetoresistance in TIPS-pentacene to the presence of electron-hole pairs under illumination as the magnetoresistive effect scales with the photocurrent. The magnetoresistance effect was found to diminish over time under ambient conditions compared to a freshly prepared sample. We propose that the much faster degradation of the magnetoresistance effect as compared to the photocurrent was due to the incorporation of water molecules in the TIPS-pentacene film.
我们报道了在环境气氛中，在具有两种不同器件结构的溶液处理的6,13-双（三异丙基甲硅烷基乙炔基）并五苯（TIPS-并五苯）平面混合器件中测量的光致负有机磁电阻（OMAR）。在这项工作中制备了沟道长度约为100 nm的具有沟槽隔离电极的混合电子器件（HED-TIE），并且为了进行比较，使用了沟道长度为20 µm的市售预结构化有机场效应晶体管（OFET）衬底。由于与OFET相比，这些器件的沟道长度要小得多，因此发现HED-TIE器件的光电流以及磁电阻的幅度更高。我们将在TIPS-并五苯中观察到的光致负磁电阻归因于光照下电子-空穴对的存在，因为磁阻效应与光电流成比例。与新制备的样品相比，发现在环境条件下磁电阻效应会随时间减弱。我们认为，与光电流相比，磁电阻效应的降解速度要快得多是由于TIPS-并五苯薄膜中掺入了水分子。
