Lead-free single crystal (Na1/2Bi1/2)TiO3-1.5at.%Bi(Zn1/2Ti1/2)O3 (NBT-1.5BZT) with dimension of phi 35mmx12mm was successfully grown by a top-seeded solution growth technique. The average and local structure were studied by a combination of X-ray diffraction and Raman spectroscopy. The electric and optical properties of <001>-oriented single crystals were investigated systematically. Compared with pure NBT, the piezoelectric constant and transmission coefficient were both enhanced, that is, from 62pC/N and similar to 60% to 121pC/N and similar to 70%, respectively. Furthermore, domain structure observation suggested that the <110>-oriented tetragonal ferroelastic domains in NBT were suppressed at room temperature with addition of BZT, which was responsible for the improved piezoelectric and optical properties of NBT-1.5BZT single crystal.