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In order to study the possible advantage of photo-assisted MOCVD compared with thermal MOCVD during the annealing process after film growth, a piece of c-axis oriented YBa2Cu3O7−δ film on Φ1″ LaAlO3 (1 0 0) substrate was prepared by photo-assisted MOCVD. It has well in-plane alignment and high critical current density (Jc > 2.5 MA/cm2, @ 0 T, 77 K, thickness ≈ 430 nm). Small pieces cut from it were annealed by photo-assisted or thermal annealing process to realize deoxidization or oxidization respectively. By monitoring the c-axis lattice constant, it was found that oxidization rate of photo-assisted annealing is obviously higher than that of thermal annealing. Inversely, the deoxidization rate of photo-assisted annealing is lower than that of thermal annealing. And a phenomenon that the long-time stable c-axis lattice constant is related to the temperature, unrelated to annealing process has been observed. It conforms to the thermodynamic equilibrium which is relative to annealing temperature and oxygen partial pressure, irrespective to whether photo activation or thermal activation.

ZrO2 nanodots are successfully prepared on LaAlO3 (LAO) (100) substrates by photo-assisted metal-organic chemical vapor deposition (MOCVD). It is indicated that the sizes and densities of ZrO2 nanodots are controllable by modulating the growth temperature, oxygen partial pressure, and growth time. Meanwhile, the microwires are observed on the surfaces of substrates. It is found that there is an obvious competitive relationship between the nanodots and the microwires. In a growth temperature range from 500 ?C to 660 ?C, the microwires turn longest and widest at 600 ?C, but in contrast, the nanodots grow into the smallest diameter at 600 ?C. This phenomenon could be illustrated by the energy barrier, decomposition rate of Zr(tmhd)4, and mobility of atoms. In addition, growth time or oxygen partial pressure also affects the competitive relationship between the nanodots and the microwires. With increasing oxygen partial pressure from 451 Pa to 752 Pa, the microwires gradually grow larger while the nanodots become smaller. To further achieve the controllable growth, the coarsening effect of ZrO2 is modified by varying the growth time, and the experimental results show that the coarsening effect of microwires is higher than that of nanodots by increasing the growth time to quickly minimize ZrO2 energy density.