Binary composition spread approach for parallel pulsed laser deposition synthesis and highthroughput characterization of transparent and semiconducting oxide thin films

Conventional 'one by one'synthesis approach has been a major rate limiting step in the systematic exploration of increasingly complex materials for the demanding new technologies. Derived from the new concepts of combinatorial chemistry, recently introduced continuous binary composition spread technique based on the non-uniformity of the deposition rate typically observed in pulsed laser deposition (PLD) is applied to the parallel growth of transparent and semiconducting oxides LixNi1-xO. A large variation of x in LixNi1-xO was achieved on a single MgO(100) substrate. Details of the synthesis technique are discussed. Microstructural, transport and optical studies were done to optimize the Li concentration in the film. XRD and AFM confirmed an epitaxial growth and smooth surface for all the Li contents. SIMS data revealed a non-linear Li variation along the film with a minimum of 0.01% of Li content. High conductivity of 1.42 ohm-1 cm-1 was obtained in sufficiently high Li concentration regions. Optical transparency beyond 80% was obtained in the 40 nm thick films. The combinatorial binary composition spread technique results in significant time and energy savings for rapidly optimizing the thin film growth parameters to explore new TCOs for future optoelectronic applications.