Porous Organic Polymer Films with Tunable Work Functions and Selective Hole and Electron Flows for Energy Conversions

Abstract

Organic optoelectronics are promising technologies for energy conversion. However, the electrode interlayer, a key material between active layers and conducting electrodes that controls the transport of charge carriers in and out of devices, is still a chemical challenge. Herein, we report a class of porous organic polymers with tunable work function as hole- and electron-selective electrode interlayers. The network with organoborane and carbazole units exhibits extremely low work-function-selective electron flow; while upon ionic ligation and electro-oxidation, the network significantly increases the work function and turns into hole conduction. We demonstrate their outstanding functions as anode and cathode interlayers in energy-converting solar cells and light-emitting diodes.

Trends and challenges for microporous polymers

“…Jiang et al developed microporous polyborane carbazol films through electropolymerization. 134 By ligating the borane centers with F À post-synthetically an anionic FPBC film was obtained and further functionalized through electrooxidation. A similar strategy was very recently applied by Feng et al generating a non-ionic borane network and afterwards ligating the boron centers with F À to obtain a permanently anionic microporous polymer.…”

“…The work function of these polymers could be tuned by ionic ligation on the central boron atom and further by electrooxidation, switching the networks from electron to hole conductors. 134 …”

Redox-active triazatruxene-based conjugated microporous polymers for high-performance supercapacitors

“…26–28 CMPs have thus emerged as a promising class of porous materials with huge application potential in gas storage and separation, heterogeneous catalysis, sensors, light harvesting, luminescence, and energy conversion. 29–31 To explore the potential of CMPs as active electrode materials for supercapacitors, CMPs with varying structures have been investigated with limited success. 32,33 The relatively low conductivity and the limited chemical and oxidative stability of established CMP linkages, such as boroxines and boronate esters, however, appear to be the main obstacles.…”

Luminescent Porous Polymers Based on Aggregation‐Induced Mechanism: Design, Synthesis and Functions

“…Porous organic polymers (POPs) are a unique class of amorphous porous polymers that combine covalent π‐networks with inherent porosity. POPs are a class of emerging multifunctional materials and show outstanding properties and functions in various applications, such as gas storage, light emitting, catalysis, energy transfer and energy storage . They are robust in stability as a result of strong covalent bond‐linked network structure and can be synthesized using a variety of different π‐units.…”