TY - JOUR
KW - Temperature
KW - Faraday effect
KW - Perovskite
KW - Probes
KW - Polarization
KW - Nanotechnology
KW - Magnetic moments
KW - Spin polarization
KW - Rotation
KW - Magnetoelectronics
KW - Semiconductor quantum wells
KW - Electrospinning
KW - Light emission
KW - Pinch effect
KW - Carrier diffusion length
KW - Electron spin polarization
KW - Electron-spin relaxation
KW - Low temperature solutions
KW - Photoinduced magnetization
KW - Polycrystalline perovskite
KW - Pump probe
KW - Time-resolved Faraday rotation
KW - Spin dynamics
AU - D Giovanni
AU - H Ma
AU - J Chua
AU - M Grätzel
AU - Ramamoorthy Ramesh
AU - S Mhaisalkar
AU - N Mathews
AU - T.C Sum
AB - Low-temperature solution-processed organic-inorganic halide perovskite CH3NH3PbI3 has demonstrated great potential for photovoltaics and light-emitting devices. Recent discoveries of long ambipolar carrier diffusion lengths and the prediction of the Rashba effect in CH3NH3PbI3, that possesses large spin-orbit coupling, also point to a novel semiconductor system with highly promising properties for spin-based applications. Through circular pump-probe measurements, we demonstrate that highly polarized electrons of total angular momentum (J) with an initial degree of polarization Pini ∼ 90% (i.e., -30% degree of electron spin polarization) can be photogenerated in perovskites. Time-resolved Faraday rotation measurements reveal photoinduced Faraday rotation as large as 10°/m at 200 K (at wavelength γ = 750 nm) from an ultrathin 70 nm film. These spin polarized carrier populations generated within the polycrystalline perovskite films, relax via intraband carrier spin-flip through the Elliot-Yafet mechanism. Through a simple two-level model, we elucidate the electron spin relaxation lifetime to be ∼7 ps and that of the hole is ∼1 ps. Our work highlights the potential of CH3NH3PbI3 as a new candidate for ultrafast spin switches in spintronics applications. © 2015 American Chemical Society.
BT - Nano Letters
DO - 10.1021/nl5039314
LA - eng
M1 - 3
N1 - cited By 75
N2 - Low-temperature solution-processed organic-inorganic halide perovskite CH3NH3PbI3 has demonstrated great potential for photovoltaics and light-emitting devices. Recent discoveries of long ambipolar carrier diffusion lengths and the prediction of the Rashba effect in CH3NH3PbI3, that possesses large spin-orbit coupling, also point to a novel semiconductor system with highly promising properties for spin-based applications. Through circular pump-probe measurements, we demonstrate that highly polarized electrons of total angular momentum (J) with an initial degree of polarization Pini ∼ 90% (i.e., -30% degree of electron spin polarization) can be photogenerated in perovskites. Time-resolved Faraday rotation measurements reveal photoinduced Faraday rotation as large as 10°/m at 200 K (at wavelength γ = 750 nm) from an ultrathin 70 nm film. These spin polarized carrier populations generated within the polycrystalline perovskite films, relax via intraband carrier spin-flip through the Elliot-Yafet mechanism. Through a simple two-level model, we elucidate the electron spin relaxation lifetime to be ∼7 ps and that of the hole is ∼1 ps. Our work highlights the potential of CH3NH3PbI3 as a new candidate for ultrafast spin switches in spintronics applications. © 2015 American Chemical Society.
PB - American Chemical Society
PY - 2015
SP - 1553
EP - 1558
T2 - Nano Letters
TI - Highly spin-polarized carrier dynamics and ultralarge photoinduced magnetization in CH3NH3PbI3 perovskite thin films
VL - 15
SN - 15306984
ER -