Thin MOF films with photoswitchable electronic properties and On-Off conductance

表面安装金属有机骨架(SURMOF)薄膜具有可光开关的电学性质和可在几个数量级内可逆变化的电导值，是本项目的目标。在我们之前发表的将螺吡喃嵌入MOF的原理证明出版物的基础上，首次展示了MOF材料的导电性的远程开关，我们将在限定的分子间距离和取向的受控位置加入螺吡喃光开关来制备可光开关的MOF薄膜。电荷转移的从头计算表明，在那里，通断比将高出三个数量级以上，导通和导通开关将是高度各向异性的，具有定向导通高速路。此外，通过MOF中光开关的有机功能化，HOMO和LUMO能级将被调谐，目的是以高度可控的方式在电子(N)和空穴(P)导电之间切换。为了演示潜在的器件实现，将制备两层膜，其中通过切换具有可切换电导的螺吡喃-SURMOF层(底层)来开启或关闭通过功能的光检测SURMOF(顶层)的自上而下的电流。此外，我们还将探索在自适应和可配置电子学中的应用，即通过聚焦光照射可逆地写入大面积SURMOF中的导线，长期目标是实现用于光计算、存储和显示的光可编程器件。在本项目中，我们涵盖了从定制的光响应有机分子的合成到可光开关MOF薄膜的制备和研究到系统集成的演示的整个研究链，结合开关和电荷转移过程的量子力学计算和多尺度模拟，以实现对器件的详细了解和指导设计。

Thin films of surface-mounted metal-organic frameworks (SURMOFs) with photoswitchable electronic properties and conductance values that can be reversibly changed over several orders of magnitude are the target of this project. Based on our previous proof-of-principle publication with spiropyran embedded in MOFs, showing for the first time the remote switching of the electric conduction of a MOF material, we will prepare photoswitchable MOF thin films with spiropyran photoswitches incorporated at controlled positions with defined intermolecular distances and orientations. There, as shown by ab initio calculations of the charge transfer, the on-off ratio will be more than three orders of magnitude higher, and the conduction as well as the conduction switching will be highly anisotropic, with oriented conduction highways. Moreover, by organic functionalization of the photoswitches in the MOF, the HOMO and LUMO levels will be tuned with the aim to switch between electron (n) and hole (p) conduction in a highly controllable fashion. To demonstrate the potential device implementation, two-layer films will be prepared where the top-down current through a functional, light-detecting SURMOF (top-layer) is switched on or off by switching the spiropyran-SURMOF-layer with switchable conductance (bottom layer). Furthermore, the application in adaptive and configurable electronics will be explored, where “conducting wires” in the large-area SURMOF are reversibly written by focused light irradiation, with the long-term goal to realize photoprogrammable devices for optical computing, memories and displays.In this project, we cover the entire research chain from the synthesis of custom-made light-responsive organic molecules over the preparation and investigation of the photoswitchable MOF films up to the demonstration of the system integration, combined with quantum-mechanical calculations and multiscale modelling of the switching and charge transfer processes in order to achieve a detailed understanding and guide the design of devices.