TY - JOUR
T1 - Postannealing effects on undoped BaSi2 evaporated films grown on Si substrates
AU - Suhara, Takamichi
AU - Murata, Koichi
AU - Navabi, Aryan
AU - Hara, Kosuke O.
AU - Nakagawa, Yoshihiko
AU - Trinh, Cham Thi
AU - Kurokawa, Yasuyoshi
AU - Suemasu, Takashi
AU - Wang, Kang L.
AU - Usami, Noritaka
N1 - Funding Information:
The authors thank Dr. T. Nie and Mr. X. Che of Device Research Laboratory (DRL) at University of California, Los Angeles (UCLA) for device fabrication. This work was realized by the Japan-US Advanced Collaborative Education Program (JUACEP) of Nagoya University and UCLA. This work was partially supported by the Core Research for Evolutionary Science and Technology of the Japan Science and Technology Agency (CREST, JST).
Publisher Copyright:
© 2017 The Japan Society of Applied Physics.
PY - 2017/5
Y1 - 2017/5
N2 - Semiconducting BaSi2 is expected as an alternative material for solar cell application because of large absorption coefficients and a suitable bandgap for single-junction solar cells. In this study, the electrical properties of undoped BaSi2 films grown by a simple vacuum evaporation method are explored. The obtained results show that an undoped evaporated film is an n-type semiconductor with a high carrier density of ∼1019 cm-3 and exhibits a metallic behavior. The quality of BaSi2 films is significantly improved by postannealing at 1000°C with surface covering to prevent oxidation. After annealing, the carrier density of BaSi2 films markedly decreases and the temperature dependence of carrier density changes from being metallic to being semiconducting. By comprehensive structural analysis, it is speculated that postannealing improves the film quality, for example, by decreasing the density of grain boundaries.
AB - Semiconducting BaSi2 is expected as an alternative material for solar cell application because of large absorption coefficients and a suitable bandgap for single-junction solar cells. In this study, the electrical properties of undoped BaSi2 films grown by a simple vacuum evaporation method are explored. The obtained results show that an undoped evaporated film is an n-type semiconductor with a high carrier density of ∼1019 cm-3 and exhibits a metallic behavior. The quality of BaSi2 films is significantly improved by postannealing at 1000°C with surface covering to prevent oxidation. After annealing, the carrier density of BaSi2 films markedly decreases and the temperature dependence of carrier density changes from being metallic to being semiconducting. By comprehensive structural analysis, it is speculated that postannealing improves the film quality, for example, by decreasing the density of grain boundaries.
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U2 - 10.7567/JJAP.56.05DB05
DO - 10.7567/JJAP.56.05DB05
M3 - Article
AN - SCOPUS:85019030708
SN - 0021-4922
VL - 56
JO - Japanese journal of applied physics
JF - Japanese journal of applied physics
M1 - 05DB05
ER -