TY - JOUR
T1 - Synthesis and Characterization of Monocrystalline GaPSi3 and (GaP)y(Si)5-2y Phases with Diamond-like Structures via Epitaxy-Driven Reactions of Molecular Hydrides
AU - Sims, Patrick E.
AU - Xu, Chi
AU - Poweleit, Christian D.
AU - Menendez, Jose
AU - Kouvetakis, John
N1 - Funding Information:
This work was supported by National Science Foundation Grant DMR-1309090. We acknowledge the use of facilities within the LeRoy Eyring Center for Solid State Science and John M. Cowley Center for High Resolution Electron Microscopy at Arizona State University. We thank Dr. Toshihiro Aoki for his assistance with the EELS spectra.
Publisher Copyright:
© 2017 American Chemical Society.
PY - 2017/4/11
Y1 - 2017/4/11
N2 - Hybrid (III-V)-(IV) alloys described using the general formula (GaP)y(Si)5-2y have been synthesized as epitaxial layers on Si(100) using specially designed chemical vapor deposition methods. Reactions of [D2GaN(CH3)2]2 with P(SiH3)3 between 525 and 540 °C gave GaPSi3 (y = 1) with a fixed Si content of 60%, while analogous reactions of [H2GaN(CH3)2]2 at >590 °C produced Si-rich derivatives with tunable Si contents in the range of 75-95% (y < 1). In both cases, diffraction studies and optical characterizations demonstrate single-phase, monocrystalline structures with an average diamond cubic lattice akin to Si. Raman scattering supports the presence of a tetrahedral structure containing isolated Ga-P pairs randomly embedded within the parent Si matrix. This outcome is consistent with theoretical simulations of a crystal growth mechanism involving interlinking GaPSi3 tetrahedra in a manner that precludes the formation of energetically unfavorable Ga-Ga bonds. Ellipsometry measurements of the dielectric function reveal systematic tuning of the absorption coefficient as a function of composition and demonstrate an enhanced optical response in the visible range relative to crystalline Si. The seamless integration with Si wafers and the intriguing optical response suggest these materials are promising candidates for optoelectronic applications.
AB - Hybrid (III-V)-(IV) alloys described using the general formula (GaP)y(Si)5-2y have been synthesized as epitaxial layers on Si(100) using specially designed chemical vapor deposition methods. Reactions of [D2GaN(CH3)2]2 with P(SiH3)3 between 525 and 540 °C gave GaPSi3 (y = 1) with a fixed Si content of 60%, while analogous reactions of [H2GaN(CH3)2]2 at >590 °C produced Si-rich derivatives with tunable Si contents in the range of 75-95% (y < 1). In both cases, diffraction studies and optical characterizations demonstrate single-phase, monocrystalline structures with an average diamond cubic lattice akin to Si. Raman scattering supports the presence of a tetrahedral structure containing isolated Ga-P pairs randomly embedded within the parent Si matrix. This outcome is consistent with theoretical simulations of a crystal growth mechanism involving interlinking GaPSi3 tetrahedra in a manner that precludes the formation of energetically unfavorable Ga-Ga bonds. Ellipsometry measurements of the dielectric function reveal systematic tuning of the absorption coefficient as a function of composition and demonstrate an enhanced optical response in the visible range relative to crystalline Si. The seamless integration with Si wafers and the intriguing optical response suggest these materials are promising candidates for optoelectronic applications.
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U2 - 10.1021/acs.chemmater.7b00347
DO - 10.1021/acs.chemmater.7b00347
M3 - Article
AN - SCOPUS:85017476956
SN - 0897-4756
VL - 29
SP - 3202
EP - 3210
JO - Chemistry of Materials
JF - Chemistry of Materials
IS - 7
ER -