Temperature-dependent direct transition energy in Ge0.99Sn0.01 film grown on Si measured by photoreflectance spectroscopy

Hyun Jun Jo; Mo Geun So; Jong Su Kim; Mee Yi Ryu; Yung Kee Yeo; John Kouvetakis

doi:10.1016/j.tsf.2015.06.008

Temperature-dependent direct transition energy in Ge_0.99Sn_0.01 film grown on Si measured by photoreflectance spectroscopy

Hyun Jun Jo
, Mo Geun So
, Jong Su Kim
, Mee Yi Ryu
, Yung Kee Yeo
, John Kouvetakis

Research output: Contribution to journal › Article › peer-review

12 Scopus citations

Abstract

Optical properties of a p-Ge_0.99Sn_0.01 film grown on an n-Si substrate have been investigated as a function of temperature and excitation laser intensity using photoreflectance (PR) spectroscopy. The Ge_0.99Sn_0.01 film was grown by ultra-high vacuum chemical vapor deposition method. Room temperature PR spectrum shows a dominant signal assigned to a direct transition from the conduction Γ valley to valence band at around 0.73 eV. The transition to spin-orbit split-off band is also observed at around 1.0 eV. In addition, Franz-Keldysh oscillations (FKOs) due to the internal electric field are observed above the direct bandgap transition energy. The direct transition energy obtained by an analysis of FKO extremum was 0.728 eV at room temperature. The internal electric fields are reduced as the laser excitation intensity increases due to the photovoltage effect. The temperature dependence of direct transition energy was also investigated.

Original language	English (US)
Pages (from-to)	295-300
Number of pages	6
Journal	Thin Solid Films
Volume	591
DOIs	https://doi.org/10.1016/j.tsf.2015.06.008
State	Published - Sep 30 2015

Keywords

Franz-Keldysh oscillations
Germanium antimonide
Photoreflectance

ASJC Scopus subject areas

Electronic, Optical and Magnetic Materials
Surfaces and Interfaces
Surfaces, Coatings and Films
Metals and Alloys
Materials Chemistry

Access to Document

10.1016/j.tsf.2015.06.008

Cite this

@article{ef7b2b70ddd148248265749cf8802130,

title = "Temperature-dependent direct transition energy in Ge0.99Sn0.01 film grown on Si measured by photoreflectance spectroscopy",

abstract = "Optical properties of a p-Ge0.99Sn0.01 film grown on an n-Si substrate have been investigated as a function of temperature and excitation laser intensity using photoreflectance (PR) spectroscopy. The Ge0.99Sn0.01 film was grown by ultra-high vacuum chemical vapor deposition method. Room temperature PR spectrum shows a dominant signal assigned to a direct transition from the conduction Γ valley to valence band at around 0.73 eV. The transition to spin-orbit split-off band is also observed at around 1.0 eV. In addition, Franz-Keldysh oscillations (FKOs) due to the internal electric field are observed above the direct bandgap transition energy. The direct transition energy obtained by an analysis of FKO extremum was 0.728 eV at room temperature. The internal electric fields are reduced as the laser excitation intensity increases due to the photovoltage effect. The temperature dependence of direct transition energy was also investigated.",

keywords = "Franz-Keldysh oscillations, Germanium antimonide, Photoreflectance",

author = "Jo, \{Hyun Jun\} and So, \{Mo Geun\} and Kim, \{Jong Su\} and Ryu, \{Mee Yi\} and Yeo, \{Yung Kee\} and John Kouvetakis",

note = "Funding Information: This work was partially supported by the 2013 Yeungnam University Research Grant . This work was supported in part by a National Research Foundation of Korea grant funded by the Korean Government ( NRF-2011-00111728 and NRF-2013K2A2A2000881 ). This work was also supported by the Human Resources Development Program (No. 20124030200100 ) of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant funded by the Korea government Ministry of Trade, Industry and Energy . This research (MYR) was also supported in part by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology ( NRF-2013R1A1A2A10058310 ). The work at ASU was supported by US Air Force Office of Scientific Research ( AFOSR ) FA9550-12-1-0208 . The authors (YKY and MYR) would like to express their sincere appreciation to Dr. Gernot S. Pomrenke of the AFOSR for his support of this work, and to Dr. Thomas Harris of the Air Force Institute of Technology for his critical reading and valuable discussion. Publisher Copyright: {\textcopyright} 2015 Elsevier B.V.",

year = "2015",

month = sep,

day = "30",

doi = "10.1016/j.tsf.2015.06.008",

language = "English (US)",

volume = "591",

pages = "295--300",

journal = "Thin Solid Films",

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T1 - Temperature-dependent direct transition energy in Ge0.99Sn0.01 film grown on Si measured by photoreflectance spectroscopy

AU - Jo, Hyun Jun

AU - So, Mo Geun

AU - Kim, Jong Su

AU - Ryu, Mee Yi

AU - Yeo, Yung Kee

AU - Kouvetakis, John

N1 - Funding Information: This work was partially supported by the 2013 Yeungnam University Research Grant . This work was supported in part by a National Research Foundation of Korea grant funded by the Korean Government ( NRF-2011-00111728 and NRF-2013K2A2A2000881 ). This work was also supported by the Human Resources Development Program (No. 20124030200100 ) of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant funded by the Korea government Ministry of Trade, Industry and Energy . This research (MYR) was also supported in part by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology ( NRF-2013R1A1A2A10058310 ). The work at ASU was supported by US Air Force Office of Scientific Research ( AFOSR ) FA9550-12-1-0208 . The authors (YKY and MYR) would like to express their sincere appreciation to Dr. Gernot S. Pomrenke of the AFOSR for his support of this work, and to Dr. Thomas Harris of the Air Force Institute of Technology for his critical reading and valuable discussion. Publisher Copyright: © 2015 Elsevier B.V.

PY - 2015/9/30

Y1 - 2015/9/30

N2 - Optical properties of a p-Ge0.99Sn0.01 film grown on an n-Si substrate have been investigated as a function of temperature and excitation laser intensity using photoreflectance (PR) spectroscopy. The Ge0.99Sn0.01 film was grown by ultra-high vacuum chemical vapor deposition method. Room temperature PR spectrum shows a dominant signal assigned to a direct transition from the conduction Γ valley to valence band at around 0.73 eV. The transition to spin-orbit split-off band is also observed at around 1.0 eV. In addition, Franz-Keldysh oscillations (FKOs) due to the internal electric field are observed above the direct bandgap transition energy. The direct transition energy obtained by an analysis of FKO extremum was 0.728 eV at room temperature. The internal electric fields are reduced as the laser excitation intensity increases due to the photovoltage effect. The temperature dependence of direct transition energy was also investigated.

AB - Optical properties of a p-Ge0.99Sn0.01 film grown on an n-Si substrate have been investigated as a function of temperature and excitation laser intensity using photoreflectance (PR) spectroscopy. The Ge0.99Sn0.01 film was grown by ultra-high vacuum chemical vapor deposition method. Room temperature PR spectrum shows a dominant signal assigned to a direct transition from the conduction Γ valley to valence band at around 0.73 eV. The transition to spin-orbit split-off band is also observed at around 1.0 eV. In addition, Franz-Keldysh oscillations (FKOs) due to the internal electric field are observed above the direct bandgap transition energy. The direct transition energy obtained by an analysis of FKO extremum was 0.728 eV at room temperature. The internal electric fields are reduced as the laser excitation intensity increases due to the photovoltage effect. The temperature dependence of direct transition energy was also investigated.

KW - Franz-Keldysh oscillations

KW - Germanium antimonide

KW - Photoreflectance

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