Lead zirconate titanate (PZT) ceramics possess great potential for practical applications and thus improving their piezoelectric properties is crucial. ${\text{Pb}}_{0.99?}$${}_x$${\text{Sm}}_{0.01}$${\text{Ba}}_x$${\text{Zr}}_{0.53}$${\text{Ti}}_{0.47}$O₃ (PSBZT) ceramics with high Curie temperature and excellent piezoelectric properties were fabricated via a conventional solid-state method, and the effect of Ba${}^{2+}$ doping on the structural, dielectric, piezoelectric and ferroelectric properties was studied in detail. It is shown that doping of Ba${}^{2+}$ significantly enhanced the piezoelectric properties of PSZT, the maximum $d_{33}～$533 pC/N and $T_c～$361${}^{°}$C at $x$= 0.02 were acquired. Furthermore, PSZT and PSBZT ceramics were used to prepare single element ultrasonic transducers, and their performance were compared and evaluated. The results demonstrate that the PSBZT ceramic-based transducer possesses better sensitivity and bandwidth than the PSZT ceramic-based transducer.