Intrinsic Exciton-Phonon Coupling and Tuning in ZnTe Nanowires Probed by Resonant Raman Scattering

Abstract

Electron-phonon coupling (EPC) in nanostructures has emerged as a critical issue in nanoscience. The change in EPC from the bulk value is pertinent in $e.g.$ phonon bottleneck, multiexciton generation, hot-electron solar cells, and laser cooling. Many ambiguous or contradictory results have been reported in the last 30 years. The authors show unambiguously that there is very little $i\phantom{\rule{0}{0ex}}n\phantom{\rule{0}{0ex}}t\phantom{\rule{0}{0ex}}r\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}n\phantom{\rule{0}{0ex}}s\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}c$ change in EPC in ZnTe nanowires, down to 30 nm in diameter; however, EPC is $e\phantom{\rule{0}{0ex}}x\phantom{\rule{0}{0ex}}t\phantom{\rule{0}{0ex}}r\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}n\phantom{\rule{0}{0ex}}s\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}c\phantom{\rule{0}{0ex}}a\phantom{\rule{0}{0ex}}l\phantom{\rule{0}{0ex}}l\phantom{\rule{0}{0ex}}y$ tunable (``programmable''), either during or after material growth, for both bulk and nanostructures. This study enables the development of practical applications and theories of EPC in reduced dimensions.