Carrier recombination efficiency and photocarrier transport in vertically aligned silicon nanowire arrays as probed by photoluminescence and terahertz spectroscopy

• Main Author: Muldera, Joselito E.
• Format: text
• Published: Animo Repository 2016
• Subjects: Nanowires; Nanosilicon; Physics
• Online Access: https://animorepository.dlsu.edu.ph/faculty_research/8136
• Institution: De La Salle University

Terahertz (THz) emission and photoluminescence (PL) spectroscopy were utilized to study the carrier dynamics and recombination characteristics of vertically align silicon nanowire synthesized by metal-assisted electroless etching, respec­tively. It is observed that the carrier dynamics is greatly affected by the presence of pores on the nanowire walls in two-step synthesized silicon nanowires compared to nanowire synthesized using a one-step process. The carriers are collected in these pores, acting as defect sites for efficient carrier r combination upon photoexcitation as shown by the temperature-dependent PL. Th pores also effectively weaken the surface electric field; thereby, deterring the mission of THz radiation. Lastly, the dependence of the THz emission on nanowire length is seen only for the nanowires synthesized by a one-stop process· while the PL intensity of the nanowire samples synthesized by the two-step process exhibited a dependence on nanowire length.