Temperature-dependent picosecond time-resolved carrier dynamics in visible-light-emitting porous silicon

• Published in: Solid state communications 1994-07, Vol.91 (3), p.239-243
• Main Authors: Wang, Jian, Wang, Wen-cheng, Zheng, Jia-biao, Zhang, Fu-long, Hou, Xiao-yuan, Wang, Xun, Wang, He-zhou, Zheng, Xi-guang
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Other solid inorganic materials; Photoluminescence; Physics
• ISSN: 0038-1098; 1879-2766
• DOI: 10.1016/0038-1098(94)90231-3

Photoluminescence mechanism and carrier dynamics for visible-light-emitting porous silicon are investigated with the use of temperature-dependent (77–400 K) and picosecond time-resolved luminescence spectroscopy. The results from porous silicon samples prepared by different post-anodic treatment methods are compared. Two excitation states with large distinct lifetimes are responsible for the visible light emission, where the higher energy state with a mono-exponential lifetime about 1 ns is revealed for the first time, which dominates the luminescence spectrum for low temperatures. At high temperatures a thermally assisted carrier transfer process occurs and a long lifetime (∼ μs) lower energy state dominates the luminescence spectrum. A possible explanation by taking both the quantum confinement effect and the surface-state mechanism as its basic framework is thus proposed.