p-π Conjugated Polyelectrolytes Toward Universal Electrode Interlayer Materials for Diverse Optoelectronic Devices

The development of universal interlayer materials for diverse optoelectronic devices not only decreases the costs in both laboratory research and industrialized production, but also improves the uniformity of different devices so as to facilitate device integration. However, using one material to fabricate diverse devices remains a great challenge. Herein, p-pi conjugation is utilize to replace the commonly used pi-pi conjugation to develop an unprecedented anode interlayer (AIL) material PCP-S that can be universally used in diverse optoelectronic devices, including organic light-emitting diode (OLED), organic solar cell (OSC), and perovskite solar cell (PSC). The unique solubility and the easy adjustment of optoelectronic properties are keys to realize the multiple uses of PCP-S. First, OSC based on the polyoxometalate (POM)-doped PCP-S exhibits a high power conversion efficiency (PCE) of 17.1%, representing the highest efficiency for OSCs using a solution-processed pH-neutral AIL. Second, PSC with PCP-S shows a PCE of 20.1%, which is superior to the device with poly(triaryl amine) (PTAA). Third, OLED possesses a significantly reduced turn-on voltage from 3.8 to 2.8 V by incorporating the PCP-S AIL. To the best of the authors' knowledge, this is the first example of a universal AIL material to realize multiple applications.