Solution processing of transparent conducting epitaxial La:BaSnO_3 films with improved electrical mobility

摘要

As a type of perovskite transparent conducting oxides, La-doped BaSnO_3 is considered as a very important material to construct all transparent perovskite devices. The difficulty in achievement of large-area films with high electrical mobility has hindered the development of La-doped BaSnO_3 films. Here, we report the results about chemical solution deposition of Ba_(0.92)La_(0.08)SnO_(3-δ) (BLSO) films. The post-annealing and atmosphere as well as lattice mismatch have been investigated. Post-annealing at 1000 ℃ can obviously improve the performance due to the enhanced crystallization. Under post-annealing in N_2 atmosphere the room-temperature resistivity and electrical mobility can achieve 3.25 mΩ cm and 11.09cm~2 V~(-1) s~(-1), respectively, for the BLSO on LaAlO_3 single crystal substrates due to the enhanced oxygen deficiencies. BLSO films with different orientation can be easily obtained by selection of the substrates, showing isotropic physical properties. Furthermore, the roorn-temperature resistivity and mobility are optimized to 1.8 mΩ cm and 23.04 cm~2 V~(-1) s~(-1) when SrTiO_3 single crystal substrates with smaller lattice mismatch are used due to the decreased dislocation density. The results will provide an alternative route to fabricate large-area transparent conducting alkaline-earth stannate films with high performance using low-cost chemical solution deposition.