Dilute tin-doped CdS nanowires for low-loss optical waveguiding

Abstract

High-quality dilute tin-doped CdS nanowires with tunable trap-state emissions were grown via simple thermal evaporation with a moving source for studying the influence of trap states on optical waveguiding. Our results demonstrate that the guiding efficiency of these wires is significantly enhanced compared to that of the pure CdS wires. Theoretical simulation based on the fundamental optical absorption principle of semiconductors further reveals that this trap-state enhanced optical waveguiding is attributed to the passive guiding process of the trap-state emissions along these wires. To the best of our knowledge, this study is the first demonstration of using dopants to shift emission away from bandgap absorption for the purpose of optical waveguiding enhancement, which is significant for understanding and optimizing the optical transport ability of semiconductor nanostructures.