Precipitation of In(OH)3 and InOOH Nanocrystals for the use in nanoelectronics: Phase Transition Behavior and Oriented Aggregation

M. Klaumünzer, M. Mackovic, P. Ferstl, M. Voigt, E. Spiecker, B. Meyer, W. Peukert
University Erlangen-Nürnberg, DE

Keywords: oriented aggregation, nanocrystals, phase transition

Summary:

With respect to diverse applications in the wide field of nanoelectronics we characterize a specific phase transition behavior and oriented aggregation (OA) during wet chemical synthesis of In(OH)3 nanocrystals as a wide band gap material and precursor material for In2O3. Contiguous to the cubic In(OH)3 phase, also orthorhombic InOOH is formed in a precipitation route with indium acetate as the In3+ source. Nano- and microcuboids are observed that consist exclusively of In(OH)3.For these In(OH)3 cuboids a three-step OA process (see Figure 2) is proposed whereas the InOOH phase stays semicrystalline even for long reaction times.Investigations were done by HRTEM, SEM, X-ray diffraction, and density functional theory (DFT) calculations.