Recent
Publications
Reprints available on request
B.
Kardasz, S. P. Watkins, E.A. Montoya, C.Burrowes, E. Girt, and B.
Heinrich, “Interface
magnetism
of
iron
grown on sulfur and hydrogen passivated GaAs(001)”, J.
Appl. Phys., 111, 07C115 (2012)
D.
Lackner, M. Steger, M.L.W. Thewalt, O. J. Pitts, Y.T. Cherng,
and S.P. Watkins, E. Plis, and S Krishna, “InAs/InAsSb
strain balanced superlattices for optical detectors: materials
properties and
energy band simulations”,
J. Appl. Phys. 111, 034507
(2012)
O.
Salehzadeh,
M. X. Chen, K. L. Kavanagh, S. P. Watkins, “Rectifying
characteristics of Te-doped GaAs nanowires”,
Appl.
Phys. Lett. 99, 182102,
(2011)
S.P. Watkins, Z.W. Deng, D.C. Li,
He. Huang, "High resolution photoluminescence spectroscopy of
donors in undoped and In-doped ZnO grown by metalorganic vapor phase
epitaxy", J. Appl.
Phys. 110, 083506 (2011)
O. Salehzadeh,
S.P.
Watkins,
"Control
of
GaAs
nanowire
morphology
by
group
III
precursor
chemistry", J.
Cryst.
Growth, 325,
5, (2011).
O. Salehzadeh,
S.P.
Watkins,
“Effect of carbon dopant on the morphology of GaAs nanowires”,
Nanotechnology
22,
165603
(2011).
D.
Lackner,
M.
Martine,
Y.
T.
Cherng,
M.
Steger,
W.
Walukiewicz,
M. L.
W. Thewalt, P. M. Mooney, and S. P. Watkins, “Electrical and optical
characterization of n-InAsSb/n-GaSb heterojunctions”, J. Appl. Phys., 107,
014512
(2010)
.
He Huang, Z.W.
Deng, D.C. Li, E. Barbir, W.Y.
Jiang, M.X. Chen, K.L. Kavanagh, P.M. Mooney, S.P Watkins, "Effect of
Annealing on Structural and Optical Properties of Heavily Carbon-Doped
ZnO",
Semicond. Sci.
Technol. 25 (2010) 045023.
W.Y. Jiang,
K.L. Kavanagh, S.P. Watkins, “Growth
mechanisms for atomic ordering in GaAsSb grown by MOVPE” J. Cryst.
Growth, 311,
4391
(2009)
D. Lackner,
O.J. Pitts, M. Steger, A. Yang,
M.L.W. Thewalt, S.P. Watkins, “Strain balanced InAsSb/InAs superlattice
structures
with optical emission to 10 microns” Appl. Phys. Lett.
95, 081906 (2009)
D. Lackner, O.
J. Pitts, S. Najmi,
P. Sandhu, K. L. Kavanagh, A. Yang, M. Steger, M. L. W. Thewalt, Y.
Wang, D. W.
McComb, C. R. Bolognesi, S. P. Watkins, “InAsSb/InAs
MQWs
grown
by
MOCVD
on
GaSb
for
mid-IR
photodetector
applications”,
J.
Cryst. Growth, 311, 3563 (2009)
R.A. Rosenberg,
M. Abu Haija, and S.P.
Watkins, “X-ray and electron induced infrared emission spectroscopy”,
Rev. Sci.
Instruments. 80,
046104 (2009)
D.L. Owen, D.
Lackner, O.J. Pitts, S.P. Watkins and P.M. Mooney, “In Place Bonding of
GaAs/InGaAs/GaAs Heterostructures to
GaAs(001)”, Semicond. Sci. Technol. 24, 035011
(2009)
O.J.
Pitts,
D.
Lackner,
Y.T.
Cherng,
S.P.
Watkins,
“Growth
of InAsSb/InPSb
heterojunctions for mid-IR detector applications”, J. Cryst. Growth, 310 4858 (2008).
D. Huang, W.Y.
Jiang, S.P. Watkins, “Flow
modulation epitaxy of ZnO films on sapphire substrates”, J. Cryst. Growth 310,
4050 (2008)
S.
Najmi,
X.K. Chen, S.P. Watkins, “Dicarbon defects in as-grown and annealed
carbon
doped InAs”, J. Appl. Phys. 102, 083528 (2007)
A.J. Clayton, A.A.
Khandekar, T.F. Kuech, N.J. Mason, M.F. Robinson, S.P. Watkins, Y. Guo,
“Growth
of AlN by vectored flow epitaxy”, J. Cryst. Growth, 298,
328
(2007).
K.
Alberi,
J.
Wu,
W.
Walukiewicz,
K.M.
Yu,
O.D.
Dubon,
S.P.
Watkins
, C.X. Wang, X.
Liu, Y.-J. Cho, and J. Furdyna, “Valence band anticrossing in
mismatched III-V semiconductor
alloys”, Phys. Rev. B75, 045203
(2007).
K. Alberi, J.
Wu, W.
Walukiewicz, K. M. Yu, O. D. Dubon, S. P. Watkins, C. X. Wang, X. Liu,
Y.-J.
Cho, and J. K. Furdyna, “Valence band anticrossing in
mismatched III-V semiconductor alloys”, Phys. Stat. Sol. (c) 4,1711 (2007)
H. G. Liu, D.W.
DiSanto, S.
P. Watkins, and C. R. Bolognesi, “InP/GaAsSb/InP DHBTs with fT
= 300 GHz and high maximum oscillation frequencies: the effect of
scaling on
device performance”, Phys. Stat. Sol.(c)
3, 4612 (2006)
Y.
Guo,
O.
J.
Pitts,
W.Jiang,
S.P.
Watkins,
“Numerical
Optimization
of
an
Optical Showerhead Reactor Design for
Organometallic Vapor Phase Epitaxy” J. Cryst. Growth, 297,
345
(2006)
S.
Najmi,
M.X.
Chen,
A.
Yang,
M.
Steger,
M.L.W.
Thewalt,
S.P.
Watkins,
“Local Vibrational Mode Study of Carbon Doped
InAs”, Phys.
Rev. B 74, 113202 (2006).
H.G. Liu, S.P. Watkins,
and C.R. Bolognesi, “15-nm base type-II InP/GaAsSb/InP DHBTs with Ft=384GHz
and
a
6-V
BVCEO”, IEEE Transactions on Electron Devices, 53,
559
(2006).
S. Najmi, X. Zhang,
X.K. Chen, M. L. W. Thewalt, S.P.
Watkins, “Raman scattering in carbon-doped InAs”, Appl. Phys. Lett. 88, 041908 (2006).
W.Y. Jiang, J.Q.
Liu, X. Zhang, M.L.W. Thewalt, K.L. Kavanagh, S.P. Watkins,
“Microstructure of
ordered nanodomains induced by Bi surfactant in OMVPE-grown GaAsSb” J.
Cryst.
Growth, 287, 541 (2006).
T.S. Rao, M.G. So,
W.Jiang, T.Mayer, S. Roorda, S.C. Gujrathi, M.L.W.Thewalt, C.R.
Bolognesi, and
S.P. Watkins, “Optical and electrical characterization of OMVPE-grown
AlGaAsSb epitaxial layers on InP
substrates”, J.
Cryst. Growth, 287, 532, (2006)
C.R. Bolognesi,
H.G. Liu, N. Tao, X. Zhang,
S. Bagheri-Najmi, and S.P. Watkins, “Neutral base
recombination in
InP/GaAsSb/InP double-heterostructure bipolar transistors: Suppression
of Auger
recombination in p+ GaAsSb base layers”, Appl.
Phys. Lett. 86,
253506 (2005).
W.Y. Jiang, J.Q. Liu,
M.G. So, K. Myrtle, K.L. Kavanagh, S.P. Watkins, “Surface modifications
induced
by bismuth on (001) GaAs surfaces” J. Cryst. Growth, 277,
85,
(2005)
L. Zheng, Z. Zhang, Y.
Zeng, S.R. Tatavarti, S.P. Watkins, C.R. Bolognesi, S. Demiguel, J.C.
Campbell,
“Demonstration of high-speed staggered lineup GaAsSb/InP Uni-traveling
carrier
photodiodes”, IEEE Photonics Technology Letters, 17,
651, (2005).
H. G. Liu, N.
Tao, S. P. Watkins, and C. R. Bolognesi,
“Extraction of
the Average Collector Velocity in High-Speed “Type-II” InP–GaAsSb–InP
DHBTs”, IEEE Electron Dev. Lett. 25,
769
(2004)
W. Jiang, J. Q. Liu,
M.G. So, T. S. Rao, K.L. Kavanagh, and S.P. Watkins, “Effect of Bi
surfactant
on atomic ordering of GaAsSb”, Appl. Phys. Lett., 85,
5589 (2004).
Z.Q. Li, V. Zhou, S.
Li, T.S. Rao, W.Y. Jiang, S.P. Watkins, “Chemical kinetics and design
of gas
inlets for III-V growth by MOVPE in a quartz showerhead reactor”
accepted in J.
Cryst. Growth, 272, 47 (2004).
O.J.
Pitts,
S.P.
Watkins,
C. X.
Wang, J. A. H. Stotz, T. A. Meyer,
M. L. W. Thewalt “Ultrathin type-II GaSb/GaAs quantum wells grown by
OMVPE”, J.
Cryst. Growth, 269, 187, (2004).
S. Lam, C.R. Bolognesi, and
S.P. Watkins, "Characterization of InP
electron-initiated impact ionization in low electric fields using
abrupt
junction NpN InP/GaAsSb/InP double heterojuntion bipolar transistors",
Appl. Phys. Lett., 83, 5548 (2003).
C.R. Bolognesi, M.W.
Dvorak, S.P. Watkins, “Type II Base-Collector
Performance Advantages and Limitations in High-Speed NPN double
heterojunction
bipolar transistors (DHBTs)” IEICE Trans. Electron. E85-C, 1929 (2003)
O.J. Pitts, S.P.
Watkins, C.X. Wang, V. Fink, and K.L. Kavanagh, "Antimony segregation
in
GaAs-based multiple quantum well structures" J. Cryst. Growth, 254,
28,
(2003)
R.D. Wiersma, J.A.H.
Stotz, O.J. Pitts, C.X. Wang, M.L.W. Thewalt, and S.P. Watkins,
"Electrical and optical properties of carbon doped GaSb", Phys. Rev. B67,
165202 (2003)
S.P. Watkins,
R.D.Wiersma, C.X. Wang, O.J. Pitts, and C.R. Bolognesi, "Structural
effects of carbon in GaSb grown by metalorganic vapor phase epitaxy",
J.
Cryst. Growth, 248, 274 (2003).
C.X. Wang, O.J.
Pitts, and S.P. Watkins, "Time-resolved
reflectance difference spectroscopy study of Sb- and As-
terminated InP(100) surfaces", J. Cryst. Growth,
248, 259 (2003).
O.J. Pitts, S.P.
Watkins, and C.X. Wang, "RDS characterization of
GaAsSb and GaSb
grown by MOVPE", J. Cryst.
Growth, 248, 249 (2003).
X.K. Chen, R. Wiersma,
C.X. Wang, O.J. Pitts, C. Dale, C.R. Bolognesi, S.P. Watkins, "Local
vibrational modes of carbon in GaSb and GaAsSb", Appl. Phys. Lett. 80, 1942 (2002).
C.R. Bolognesi, M.W.
Dvorak, N. Matine, O.J. Pitts, S.P. Watkins, "Ultrahigh performance
staggered lineup ("Type-II") InP/GaAsSb/InP NpN double heterojunction
bipolar transistors", Jpn. J. Appl. Phys. 41,1131
(2002).
C.R. Bolognesi,
N.Matine, M.W. Dvorak, P. Yeo, X.G. Xu, and S.P Watkins,
"InP/GaAsSb/InP
double HBTs: a new alternative for InP-based DHBTs", IEEE Trans.
Electron
Dev., 48, 2631 (2001).
R. Wiersma, J.A.H.
Stotz, O.J. Pitts, C.X. Wang, M.L.W. Thewalt, and S.P. Watkins,
"P-type carbon doping of
GaSb", J. Electron. Materials, 30,
1429 (2001).
O.J. Pitts, S.P.
Watkins, C.X. Wang, J.A.H. Stotz, and M.L.W. Thewalt, "in
situ monitoring, structural and
optical properties of ultrathin GaSb/GaAs quantum wells, grown by
OMVPE",
J. Electron. Materials, 30, 1412
(2001).
V. Fink, E. Chevalier,
O.J. Pitts, M.W. Dvorak, K.L. Kavanagh, C.R. Bolognesi, S.P. Watkins,
S.
Hummel, N. Moll, "Anisotropic resistivity
correlated with atomic ordering in p-type GaAsSb", Appl. Phys.
Lett., 79, 2384 (2001).
M.W. Dvorak, C.R.
Bolognesi, O.J. Pitts, S.P. Watkins, "300 GHz
InP/GaAsSb/InP double
HBTs with high current capability and BVCEO ³6V", IEEE Electron Device
Lett., 22, 361 (2001).
M. W. Dvorak, N. Matine, C.
R. Bolognesi, X. G. Xu and S. P.
Watkins, "Design
and performance of InP/GaAsSb/InP double heterojunction bipolar transistors", J. Vac. Sci.
Technol. A 18, 761 (2000).
S.P. Watkins, T.
Pinnington, J. Hu, P. Yeo, M. Kluth. N.J. Mason, R.J. Nicholas and P.J.
Walker,
"Infrared single wavelength gas composition monitoring for metalorganic
vapour phase epitaxy", J. Cryst.
Growth, 221, 166 (2000).
S.P. Watkins, O. Pitts,
C. Dale, X.G.Xu, M. Dvorak, N. Matine,
and C.R. Bolognesi, "Heavily carbon-doped GaAsSb grown on InP for HBT
applications", J. Cryst. Growth, 221, 59 (2000).
R. Beaudry, X.G. Xu,
and S.P. Watkins, "Photoreflectance study of phosphorous passivation of
GaAs" J. Appl. Phys. 87, 7838
(2000).
C. R. Bolognesi and
S.
P. Watkins, "InP-Based Double Heterojunction
Bipolar Transistors: It
May Not Have to be GaInAs", Compound
Semiconductor
6, 94 (2000).
J.A. Gupta, S.P.
Watkins, E.D. Crozier, J.C. Woicik, D.A. Harrison, D. Jiang, I.J.
Pickering,
and B.A Karlin, "Layer perfection in ultrathin InAs quantum wells in
GaAs
(001)", Phys. Rev. B61,
2073(2000).