n-Type acceptor–acceptor polymer semiconductors

<正>Polymer semiconductors have aroused interests from both academic and industry due to their wide applications in electronic devices, such as organic thin-film transistors（OTFTs）[1], polymer solar cells（PSCs）[2-6], organic thermoelectrics（OTEs）[7-11], and perovskite solar cells（PVSCs）[12-14]. To date,great efforts have been devoted to developing p-type polymer semiconductors, while the development of n-type polymers lags far behind. In fact, n-type polymers are essential for organic electronic devices.