CdSeS Nanowires: Compositionally Controlled Band Gap and Exciton Dynamics.
CdS, CdSe, and ternary CdSexS(1-x) are some of the most widely studied II-VI semiconductors due to their broad range of applications and promising performance in numerous systems. One-dimensional semiconductor nanowires offer the ability to conduct charges efficiently along the length of the wire, which has potential charge transport benefits compared to nanoparticles. Herein, we report a simple, inexpensive synthetic procedure for high quality CdSeS nanowires where the composition can be easily modulated from pure CdSe to pure CdS by simply adjusting the Se:S precursor ratio. This allows for tuning of the absorption and emission properties of the nanowires across the visible spectrum. The CdSeS nanowires have a wurtzite crystal structure and grow along the [001] direction. As measured by femtosecond transient absorption spectroscopy, the short component of the excited state lifetime remains relatively constant at ∼10 ps with increasing Se; however, the contribution of this short lifetime component increased dramatically from 8.4% to 57.7% with increasing Se content. These CdSeS nanowires offer facile synthesis and widely adjustable optical properties, characteristics that give them broad potential applications in the fields of optoelectronics, and photovoltaics.
‡Busan Center, Korea Basic Science Institute, Busan 618-230, Korea.
Jong-Pil
JP
Kim
Jeffrey A
JA
Christians
Hyunbong
H
Choi
Sachidananda
S
Krishnamurthy
Prashant V
PV
Kamat
CdSeS; band gap; charge dynamics; emission; nanowires; transient absorption spectroscopy