The active electron concentration was obtained as large as . The tensile strain level in the Sb-doped Ge epilayers was twice larger than that of the P-doped Ge films using GaP solid source or PH3 gas precursor. The results have a significant suggestion in the realization of Si-based photoelectronic devices that could be compatible to the main stream CMOS technology. | VNU Journal of Science: Mathematics – Physics, Vol. 34, No. 3 (2018) 48-54 Optical Properties of Sb Doped Ge Films Deposited on Silicon Substrate by Molecular Beam Epitaxy Luong Thi Kim Phuong1,* Le Thanh Vinh2, Abdelhamid Ghrib3, Moustafa El Kurdi3, Philippe Boucaud3, Nguyen Thi Quynh Nga4 1 Hong Duc University, 565 Quang Trung Street, Dong Ve District, Thanh Hoa City, Viet Nam Aix- Marseille University, CNRS CINaM- UMR 7325, F-13288 Marseille Cedex 09, France 3 Institut d'Electronique Fondamentale, CNRS UMR 8622, Université Paris-Sud, Bât. 220, F-91405 Orsay, France 4 Dao Duy Tu High School Thanh hoa City, Viet Nam 2 Received 08 March 2018 Revised 06 September 2018; Accepted 08 September 2018 Abstract: To enhance the photoluminescence efficiency of the Ge films, we can apply a tensile strain or introduce an electron doping in the Ge epi-layers for engineering the energy band gap of the Ge bulk. In this work, we combined both the electron doping method from a Sb source and a tensile strain via two-step growth in the Ge films. Sb-doped Ge films were grown on Si(001) substrate by molecular beam epitaxy technique. The dependence of the photoluminescence intensity on the substrate temperature in the range of 130-240oC and on the Sb source temperature from 240 to 300oC were investigated. The active electron concentration was obtained as large as . The tensile strain level in the Sb-doped Ge epilayers was twice larger than that of the P-doped Ge films using GaP solid source or PH3 gas precursor. The results have a significant suggestion in the realization of Si-based photoelectronic devices that could be compatible to the main stream CMOS technology. Keywords: n-doped Ge; Sb source; photoluminescence; tensile strain; optoelectronic. 1. Introduction Photonics and optoelectronics play an important role in many fields of communication and information technology. In recent years, research on tensile strain Ge/Si with high electron doping has been .