Abstract
The wide-bandgap, semiconducting ternary compound Hg3Se2I2 has shown promise as room-temperature hard-radiation detector. Since this compound was first reported, there has been significant improvement in crystal growth using a chemical vapor transport method with a polyethylene growth agent. To study the effects of this additional precursor on crystal quality, the nature of radiative and nonradiative defects using photoluminescence (PL) and photocurrent (PC) studies of Hg3Se2I2 single crystals are investigated. In contrast to earlier studies, excitation intensity-dependence of PL emission shows that the near-band-edge (NBE) emission bands are all excitonic in nature. The PL intensity decreases with increasing temperature, with the higher energy peaks quenching by 40 K and the deeper levels quenched after 110 K. The PC spectra show a complex structure at room temperature related to NBE transitions in the band structure, while at low temperature only the direct gap transition is observed due to phonons freezing out. The PC spectra at low temperature also indicate several midgap levels that are attributed to native defects within the bulk crystal. These results indicate that the high quality of Hg3Se2I2 single crystals is maintained when the transport agent is used during growth, although there are still a variety of defects present.
| Original language | English |
|---|---|
| Journal | Advanced Optical Materials |
| DOIs | |
| Publication status | Accepted/In press - Jan 1 2018 |
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Keywords
- photocurrent spectroscopy
- photoluminescence
- wide-bandgap semiconductors
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics
Cite this
Deep Level and Near-Band-Edge Recombination in Semiconducting Antiperovskite Hg3Se2I2 Single Crystals. / Das, Sanjib; McCall, Kyle M.; Peters, John A.; He, Yihui; Kim, Joon Il; Liu, Zhifu; Kanatzidis, Mercouri G; Wessels, Bruce W.
In: Advanced Optical Materials, 01.01.2018.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Deep Level and Near-Band-Edge Recombination in Semiconducting Antiperovskite Hg3Se2I2 Single Crystals
AU - Das, Sanjib
AU - McCall, Kyle M.
AU - Peters, John A.
AU - He, Yihui
AU - Kim, Joon Il
AU - Liu, Zhifu
AU - Kanatzidis, Mercouri G
AU - Wessels, Bruce W.
PY - 2018/1/1
Y1 - 2018/1/1
N2 - The wide-bandgap, semiconducting ternary compound Hg3Se2I2 has shown promise as room-temperature hard-radiation detector. Since this compound was first reported, there has been significant improvement in crystal growth using a chemical vapor transport method with a polyethylene growth agent. To study the effects of this additional precursor on crystal quality, the nature of radiative and nonradiative defects using photoluminescence (PL) and photocurrent (PC) studies of Hg3Se2I2 single crystals are investigated. In contrast to earlier studies, excitation intensity-dependence of PL emission shows that the near-band-edge (NBE) emission bands are all excitonic in nature. The PL intensity decreases with increasing temperature, with the higher energy peaks quenching by 40 K and the deeper levels quenched after 110 K. The PC spectra show a complex structure at room temperature related to NBE transitions in the band structure, while at low temperature only the direct gap transition is observed due to phonons freezing out. The PC spectra at low temperature also indicate several midgap levels that are attributed to native defects within the bulk crystal. These results indicate that the high quality of Hg3Se2I2 single crystals is maintained when the transport agent is used during growth, although there are still a variety of defects present.
AB - The wide-bandgap, semiconducting ternary compound Hg3Se2I2 has shown promise as room-temperature hard-radiation detector. Since this compound was first reported, there has been significant improvement in crystal growth using a chemical vapor transport method with a polyethylene growth agent. To study the effects of this additional precursor on crystal quality, the nature of radiative and nonradiative defects using photoluminescence (PL) and photocurrent (PC) studies of Hg3Se2I2 single crystals are investigated. In contrast to earlier studies, excitation intensity-dependence of PL emission shows that the near-band-edge (NBE) emission bands are all excitonic in nature. The PL intensity decreases with increasing temperature, with the higher energy peaks quenching by 40 K and the deeper levels quenched after 110 K. The PC spectra show a complex structure at room temperature related to NBE transitions in the band structure, while at low temperature only the direct gap transition is observed due to phonons freezing out. The PC spectra at low temperature also indicate several midgap levels that are attributed to native defects within the bulk crystal. These results indicate that the high quality of Hg3Se2I2 single crystals is maintained when the transport agent is used during growth, although there are still a variety of defects present.
KW - photocurrent spectroscopy
KW - photoluminescence
KW - wide-bandgap semiconductors
UR - http://www.scopus.com/inward/record.url?scp=85052959181&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85052959181&partnerID=8YFLogxK
U2 - 10.1002/adom.201800328
DO - 10.1002/adom.201800328
M3 - Article
JO - Advanced Optical Materials
JF - Advanced Optical Materials
SN - 2195-1071
ER -