Kinetics of excitonic complexes on tunneling devices

Abstract

In this work we have investigated the effects of trion formation on the tunneling current from both experimental and theoretical viewpoints. We have measured the current-voltage characteristics and the quantum-well photoluminescence emission of GaAs-Ga 1−x Al x As n-i-n double barrier diodes. We have observed a preresonance shoulder in the current-voltage curve under high laser intensities associated with the formation of trions in the quantum well, which increase the number of free states in the resonant and excitonic levels, thus enhancing the tunneling mechanism. These excitonic complexes were detected through the photoluminescence spectra under bias. We have observed that the preresonance shoulder occurs under the same conditions for which a trion peak in the luminescence spectrum is present. This trion-assisted mechanism is terminated when neutral and charged excitons are dissociated either by thermal excitation or by scattering with free carriers in the quantum well. A phenomenological rate equation model has allowed us to confirm our assumptions on the effect of trion formation on the charge transport.

Circular polarization in n-type resonant tunneling diodes with Si delta-doping in the quantum well

“…We observed that the PL intensity shows a good correlation with the I(V) characteristics curve. In addition, in the electron resonant condition, the QW PL peak emission splits in two peaks separated by about 2.5 meV which is consistent with the formation of trions in the QW [22][23][24][25]. We have also observed that QW emission band presents a shift to lower energies due to the Stark effect.…”

Quantum plasmonic hot-electron injection in lateral WSe2/MoSe2 heterostructures

“…where 𝛤 𝐶𝑇 𝐺 𝐻𝐸𝐼 is the hot electron injection (HEI) rate, and 𝛤 𝐶𝑇 𝑅 𝐻𝐸𝐼 is the hot electron decay rate from states |𝑋 0 ⟩ or |𝑌 0 ⟩ [63]. We assume 𝐺 𝐻𝐸𝐼 = 𝑅 𝐻𝐸𝐼 = 1.…”

Zeeman splitting and spin dynamics tuning by exciton charging in two-dimensional systems

“…The spin-relaxation dynamics, in the case of trions, appears linked to the simultaneous presence of excitons. Both complexes share the same source of carriers 23 thus their spin statistics should be intertwined. The statistics underneath the carriers dynamics and charge imbalance in the simultaneous occupation of exciton and trion states leads to the anomalous DCP of the trion X − .…”

“…(Color online) Theoretical calculations of the degree of circular polarization for the neutral exciton, X 0 : dotted and dashed curves, without considering the valence band hybridization, and solid curves (considering the valence band hybridization tuning with magnetic field varying the parameter τ s /τ within the range [1.0,3.0]).trions, X − , are governed by the equations23 …”