tailieunhanh - Structural and optical properties in near infrared of CdTeSe coloidal quantum dots for potential application in solar cells

This report presents the results on the optical properties of CdTeSe ternary alloyed quantum dots (QDs) fabricated by colloidal chemical method. We have used the micro-Raman spectra as a tool to determine the formation of CdTeSe alloy phase, the composition ratio of Te:Se when fabricated at different temperatures from 180 oC to 280 oC. | Vietnam Journal of Science and Technology 55 (4) (2017) 515-525 DOI: STRUCTURAL AND OPTICAL PROPERTIES IN NEAR INFRARED OF CdTeSe COLOIDAL QUANTUM DOTS FOR POTENTIAL APPLICATION IN SOLAR CELLS Pham Nam Thang1, 3, Le Xuan Hung2, 3, Nguyen Thi Minh Chau1, 3, Vu Thi Hong Hanh4, Nguyen Ngoc Hai5, Nguyen Thi Thuc Hien2, Pham Thu Nga1, 2, * 1 Institute of Materials Science, VAST, 18 Hoang Quoc Viet Road, Cau Giay District, Hanoi 2 3 Institute of Research and Development, Duy Tan University, Da Nang Graduate University of Science and Technology, VAST, 18 Hoang Quoc Viet Road, Hanoi 4 Faculty of Physics, Thai Nguyen University of Education, Thai Nguyen 5 Department of Education and Formation, Quang Ninh, Viet Nam * Email: phtnga@, ngalamvn@ Received: 13 January 2017; Accepted for publication: 30 July 2017 ABSTRACT This report presents the results on the optical properties of CdTeSe ternary alloyed quantum dots (QDs) fabricated by colloidal chemical method. We have used the micro-Raman spectra as a tool to determine the formation of CdTeSe alloy phase, the composition ratio of Te:Se when fabricated at different temperatures from 180 oC to 280 oC. The intensity ratio of two vibration lines at 159 cm-1 and 188 cm-1 allows the determination of Te:Se composition ratio available in QD samples. The Raman spectra of CdTexSe1-x when x changes between 0, , , , , and 1, fabricated at 260 oC, shows clearly the change in intensity of the optical vibration lines. The absorption and emission spectra of CdTeSe QDs show that the absorption edge of these QDs shifts up to 880 nm and up to ~ 860 nm for the emission. Detailed studies on size, structural, vibrational and optical characteristics of ternary alloyed QDs are also discussed. The absorption region of fabricated CdTeSe QDs is completely suitable for usage in solar cells. Keywords: CdTeSe alloyed quantum dots, Raman spectra, PL spectra, absorption, TEM .