The thermal, optical, electrochemical, and electronic properties of the copolymers P(T-Qx), P(BDT-Qx), and P(BDT-DTQx), based on the electron-deficient Qx unit, are fully characterized as presented by Yuanhe Fu, Hyojung Cha, Seulki Song, Gang-Young Lee, Chan Eon Park, and Taiho Park on page 372. P(T-Qx) exhibits the most rigid planar structure of the three copolymers. The lower hole mobility of P(BDT-DTQx) than that of P(T-Qx) indicates that the incorporation of a BDT unit does not improve the photoactive materials of Qx-based copolymers. This systematic study deepens the understanding of the role of BDT in Qx-based copolymer systems. The principles described here may be extended to other types of donor and acceptor units toward the design of a novel class of photoactive materials.