Synthesis, characterization, and thermal decomposition of single source precursors to nanocrystalline binary and ternary 13-15 materials

The growing application of semiconductor materials continually invigorates research into their preparation. The use of single source precursors for the formation of 13–15 materials is advantageous in that it reduces or eliminates many of the safety concerns that plague the conventional industrial methods of 13–15 materials preparation, namely OMCVD and MBE. Additionally, the temperatures required for the conversion of a 13–15 single source precursor to its corresponding material are significantly reduced relative to conventional methods. Finally, single source precursors, upon thermolysis, have a propensity to form materials on the nanoscale size regime—an important feature as the drive toward smaller and smaller devices continues.; The research presented herein is focused on two aspects: (1) the preparation and characterization of novel organometallic single source precursor compounds and (2) the thermal decomposition of the precursors to form nanocrystalline binary and ternary 13–15 materials.; The utilization of a new class of compounds, the lithium pnictidometallates, as reagent materials for the preparation of precursors to ternary 13–15 materials was investigated with interesting results. Novel ligand replacement and molecular rearrangement accompanied the expected lithium halide coupling reactions as evinced by the isolation of the mixed group 13 compound (Me ₃Si)₂P(Cl)Ga[μ–P(SiMe₃)₂] ₂B(H)Me) (4).; Dehalosilylation methodology was also applied for the formation single source precursors to nanocrystalline binary and ternary 13–15 materials. Reactions involving diethyl gallium chloride and diethyl indium chloride with tris(trimethylsilyl)phosphine, arsine, and stibine resulted both in oligomeric 13–15 compounds such as the dimeric [Et₂InP(SiMe₃) ₂]₂ (8) as well as mixed pnicogen compounds such as (Me₃Si)₂P[μ–GaEt₂] ₂Sb(SiMe₃)₂ (12). These compounds were subsequently pyrolyzed using bulk thermolysis techniques.; Powder X-ray diffraction and elemental analysis of the powders by obtained from the bulk thermolyses experiments showed not only that the precursors decompose to form their respective binary and ternary 13–15 materials, but also that the materials formed are in the nanocrystalline size regime.; Finally, the thermal decomposition of precursors to binary 13–15 materials was investigated using the combined technique of thermogravirnmetric analysis - mass spectrometry. This technique allowed for the mass analysis of the volatile elimination products produced during the thermolyses of the series of precursors, [Et₂ME(SiMe₃)2]_n (M = Ga; E = P, As, Sb; M = In; E = P, As; n = 2; M = In; E = Sb; n = 3). Based on this analysis, the assignment of the primary mode of decomposition of these precursors as that of group 13–C and pnicogen–Si bond homolysis was made.