Pham, Phuong, Trung Tran, and Khoa Pham. “Improverment of Electrical and Optical Properties of Doped Amorphous Silicon Layers Applied to Heterojunction Solar Cells”. VNUHCM Journal of Science and Technology Development 18, no. 3 (August 30, 2015): 55-60. Accessed September 3, 2025. http://stdj.scienceandtechnology.com.vn/index.php/stdj/article/view/820.