@article{1dd0833862864330bbd2fded240a6620,
title = "Temperature-dependent photoluminescence of Ge/Si and Ge 1-ySny/Si, indicating possible indirect-to-direct bandgap transition at lower Sn content",
abstract = "Temperature (T)-dependent photoluminescence (PL) has been investigated for both p-Ge and n-Ge1-ySny films grown on Si substrates. For the p-Ge, strong direct bandgap (ED) along with weak indirect bandgap related (EID) PL at low temperatures (LTs) and strong E D PL at room temperature (RT) were observed. In contrast, for the n-Ge1-ySny, very strong dominant EID PL at LT and strong ED PL were observed at RT. This T-dependent PL study indicates that the indirect-to-direct bandgap transitions of Ge 1-ySny might take place at much lower Sn contents than the theory predicts, suggesting that these Ge1-ySny could become very promising direct bandgap semiconductors.",
author = "Ryu, {Mee Yi} and Harris, {Tom R.} and Yeo, {Y. K.} and Beeler, {R. T.} and John Kouvetakis",
note = "Funding Information: The authors would like to thank Dr. Jose Men{\'e}ndez of the Arizona State University for his critical reading and valuable discussion. The authors also would like to express their sincere appreciation to Dr. Gernot S. Pomrenke of the Air Force Office of Scientific Research for his support of this work. 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 (2010-0021555). The views expressed in this article are those of the authors and do not reflect the official policy or position of the United States Air Force, Department of Defense, or the United States Government.",
year = "2013",
month = apr,
day = "29",
doi = "10.1063/1.4803927",
language = "English (US)",
volume = "102",
journal = "Applied Physics Letters",
issn = "0003-6951",
publisher = "American Institute of Physics Publising LLC",
number = "17",
}