With solution-processability, low-temperature proper energy level and superior stability, poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) is one common hole-transport material for the quantum dot light-emitting diode (QLED) application. However, the conductivity of the traditional PEDOT:PSS is very low, which has an adverse effect on QLED devices. Herein, one surface-annealing method for the PEDOT:PSS film to exchange their original composition and surface morphology is proposed. The advantage of this approach lies in the fact that the conductivity of the PEDOT:PSS film annealed with toluene (1.25 S cm−1) and ethylene glycol (EG, 10.52 S cm−1) are obviously improved compared with the air-annealing method (0.13 S cm−1). The difference is that the EG-washed PEDOT:PSS film shows a relatively rough surface with more PEDOT domains, whereas the toluene treated PEDOT:PSS film can promote the formation of a smooth, PSS-dominated surface and change the PEDOT chain structure from coiled to linear, thus, the conductivity of the PEDOT:PSS film is enhanced. As a result, the QLED device achieves a maximum luminance of 31 140 cd m−2 and power efficiency of 13.4 lm W−1, showing 48% and 25% enhancements, respectively, compared to the control device. This work provides an efficient approach for improving of perovskite QLED performance.
Liquid metal (LM)-based polymers have received growing interest for wearable health monitoring, electronic skins, and soft robotics. However, fabricating multifunctional LM-based polymers, in particular, featuring a convenient shaping ability while offering excellent deformability and conductivity remains a challenge. To overcome this obstacle, here, we propose a strategy to prepare LM-Gel “plasticine” (LGP) with great deformability, which is composed of a PVA (poly(vinyl alcohol)) soft network and an LM conductive phase. LGP can be easily constructed into different shapes such as plasticine and can be applied to different conditions (such as building a 3D circuit, circuit repair, and switch). Meanwhile, LGP has great conductivity (2.3 × 104 S/m) after surface annealing. Besides, LGP has a good electric heating performance, which shows the potential for application in wearable heating devices. Thus, this approach not only provides a way to prepare LM-polymer plasticine but also provides a novel perspective toward extending the applied range of LM-polymer composites.