NTRS - NASA Technical Reports Server

Back to Results
Organometallic chemical vapor deposition and characterization of ZnGe(1-x)Si(x)P2-Ge alloys on GaP substratesThe epitaxial growth of ZnGe(1-x)Si(x)P2-Ge alloys on GaP substrates by open tube organometallic chemical vapor deposition (OMCVD) is reported. The chemical composition of the alloys characterized by energy dispersive X-ray spectroscopy shows that alloys with x up to 0.13 can be deposited on (001) GaP. Epitaxial growth with mirror smooth surface morphology was achieved for x less than or equal to 0.05. Transmission electron microscopy (TEM) micrographs of these alloys show specular epitaxy and the absence of microstructural defects indicating a defect density of less than 10(exp 7) cm(sup -2). Selected area electron diffraction pattern of the alloy shows that the epitaxial layer crystallizes in the chalcopyrite structure with relatively weak superlattice reflections indicating certain degree of randomness in the cation sublattice. Hall measurements show that the alloys are p-type, like the unalloyed films; the carrier concentration, however, dropped about 10 times from 2 x 10(exp 18) to 2 x 10(exp 17) cm(sup -3). Absorption measurements indicate that the band tailing in the absorption spectra of the alloy was shifted about 0.04 eV towards shorter wavelength as compared to the unalloyed material. Diodes fabricated from the n(+)-GaP/p-ZnSiP2-ZnGeP2-Ge heterostructure at x = 0.05 have a reverse break-down voltage of -10.8 V and a reverse saturation current density of approximately 6 x 10(exp -8) A/sq cm.
Document ID
Document Type
Reprint (Version printed in journal)
Xing, G. C.
(North Carolina State Univ. Raleigh, NC, United States)
Bachmann, Klaus J.
(North Carolina State Univ. Raleigh, NC, United States)
Posthill, J. B.
(Research Triangle Inst. Research Triangle Park, NC., United States)
Timmons, M. L.
(Research Triangle Inst. Research Triangle Park, NC., United States)
Date Acquired
August 16, 2013
Publication Date
January 1, 1993
Publication Information
Publication: Memory Effects in the Organometallic Chemical Beam Epitaxy of Compound Semiconductors
Subject Category
Solid-State Physics
Distribution Limits
Work of the US Gov. Public Use Permitted.
No Preview Available