| Abstract [eng] |
This dissertation is dedicated to the development of thin-layer synthesis of n-type semiconductor lanthanum-doped barium stanate (La:BaSnO3) by PI-MOCVD and investigation of thin-film properties. La:BaSnO3 (LBSO) is a material that is transparent to visible light and has low electrical resistance and high electron mobility. Due to its optical, electrical properties and perovskite-type structure, thin LBSO layers could be applied in optoelectronics. This work investigates the so far undeveloped deposition method of PIMOCVD synthesis of thin LBSO layers and the non-stoichiometry related properties. After studying and selecting suitable metalorganonic precursors, thin layers of tin oxide were successfully deposited and their growth kinetics were compared using various Sn precursors. Using Ba, La and Sn precursors, layers of undoped barium stanate (BaSnO3) and lanthanum doped barium stanate (La:BaSnO3) were deposited. XRD analysis have shown that polycrystalline, textured or epitaxial layers were formed depending on the lattice structure of the crystalline substrates. Their microstructure, morphology, optical and electrical properties varied significantly with different layer molar Sn / Ba ratio. Three different layer growth morphologies were identified as the Sn / Ba molar ratio varied. Control of non-stoichiometry in epitaxial layers allowed to achieve a relatively high quality of microstructure. With a small deviation to the Ba excess, the layers had the best properties - high surface smoothness, high microstructural quality, transmission in the visible spectrum, high electron mobility and low resistance. In this work, particularly good electrical properties of the LBSO layers were achieved. |
