Unveiling the ultrafast optoelectronic properties of 3D Dirac semi-metal Cd3As2

We employ ultrafast optical-pump terahertz-probe spectroscopy and ultrafast THz emission spectroscopy to investigate the ultrafast charge carrier dynamics in the 3D Dirac semi-metal Cd
₃
As
₂
. We extract the temperature-dependent electron mobility (16,000cm
²
V
^-1
s
^-1
at 5K) for Cd
₃
As
₂
nanowire ensemble. We also demonstrate strong THz emission from both Cd
₃
As
₂
single crystal and nanowires, whose polarity depends strongly on incident angle and pump polarisation.