Gas-Phase reaction mechanism of InN MOVPE: A systematic DFT study

In this project, we systematically investigated the gas-phase reaction mechanisms in InN MOVPE process through density functional theory (DFT) computations. We proposed all possible major reactions in InN MOVPE process starting with TMIn/NH3 as reactants and performed throughout mechanistic studies between reactants and in-termediates in various scenarios. The main reaction pathways were mapped after carefully comparing the changes in reaction Gibbs energy (Delta G) and the energy barrier (Delta G*/RT) for all reaction steps. Our computations suggest that the competition between adduct/amide and the direct pyrolysis paths is temperature-dependent when the reaction is not interfered by the radicals, and the former is preferred when T < 602.4 K (and higher T would boost pyrolysis). Our studies also suggest that adduct/amide reactions can also occur between the pyrolysis products and NH3, generating InNH2. Moreover, our computations reveal that, if H radicals participate, InH3 is highly likely to form in InN MOVPE. Meanwhile, the substitution on methyl group will transform TMIn to DMInNH2 when NH2 partakes in the reaction. The consequent substitutions on In can eventually converted into In(NH2)3 and obstruct further radical interactions.