Emergent properties from CuPd alloy films under near-infrared excitation
Abstract
Noble-transition metal alloys offer emergent optical and electronic properties for near-infrared (NIR) optoelectronic devices. We investigate the optical and electronic properties of CuxPd1−x alloy thin films and their ultrafast electron dynamics under NIR excitation. Ultraviolet photoelectron spectroscopy measurements supported by density functional theory calculations show strong d-band hybridization between the Cu 3d and Pd 4d bands. These hybridization effects result in emergent optical properties, most apparent in the dilute Pd case. Time-resolved terahertz spectroscopy with NIR (e.g., 1550 nm) excitation displays composition-tunable electron dynamics. We posit that the negative peak in the normalized increment of transmissivity (ΔT/T) below 2 ps from dilute Pd alloys is due to non-thermalized hot-carrier generation. On the other hand, Pd-rich alloys exhibit an increase in ΔT/T due to thermalization effects upon ultrafast NIR photoexcitation. CuxPd1−x alloys in the dilute Pd regime may be a promising material for future ultrafast NIR optoelectronic devices.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Nov 01, 2022
- Source ID
- 10.1063/5.0102066
Entities
People
- Gregory Manoukian
- Jason B Baxter
- Karunya Shirali
- Kevin M McPeak
- Luis D. B. Manuel
- Orhan Kizilkaya
- Phillip T. Sprunger
- Sergi Lendinez
- Tiago R. Leite
- William A. Shelton
Organizations
- Army Research Office
- Drexel University
- Louisiana State University
- National Science Foundation