Solution-processed perfect uniaxial orientation of perovskite titanate (Ca_(0.65)Sr_(0.35))_(0.997)Pr_(0.002)TiO_3 phosphor thin films

摘要

We report the preparation of perfect uniaxially-oriented (Ca_(0.65)Sr_(0.35))_(0.997)Pr_(0.002)TiO_3phosphor thin films on glass substrates with an oriented Dion-Jacobson perovskite RbLaNb_2O_7 seed layer prepared using an excimer-laser-assisted metal organic deposition process. The obtained phosphor thin films on the seed layer exhibited perfect uniaxial (010)-orientation below 40 mJ/cm~2. At 40 mj/cm~2, the film showed intense red luminescence at 612 nm. The luminance was evaluated to be 14.5 cd/m~2 under 300 nm excitation light at 3.5 mW/cm~2, and this value was 26% higher than that of unoriented film. Above 45mJ/cm~2, the phosphor thin films had a mud-crack pattern. Thus, the crystal orientation quality and luminescence intensity was lowered. The precise control of preparation conditions is necessary for preparation of heterostructures with good orientation quality.