Spatial control of carrier capture in two-dimensional materials: Beyond energy selection rules

Abstract

Transition metal dichalcogenide monolayers have attracted wide attention due to their remarkable optical, electronic and mechanical properties. In these materials local strain distributions effectively form quasi zero-dimensional potentials, whose localized states may be populated by carrier capture from the continuum states. Using a recently developed Lindblad single-particle approach, here we study the phonon-induced carrier capture in a MoSe2 monolayer. Although one decisive control parameter is the energy selection rule, which links the energy of the incoming carriers to that of the final state via the emitted phonon, we show that additionally the spatio-temporal dynamics plays a crucial role. By varying the direction of the incoming carriers with respect to the orientation of the localized potential, we introduce a new control mechanism for the carrier capture: the spatial control.

Optical fingerprint of bright and dark localized excitonic states in atomically thin 2D materials

“…The approximation of a Gaussian disorder potential is well established in theory [41][42][43] and moreover, experimentally measured potential traps reveal a Gaussian-like behavior [19,22]. Note that our theory is not limited to Gaussian potentials but could be extended to other potential forms, such as elliptical [44] or nanobubbles [45]. The investigated Gaussian potential in its general form can have its origin in a variety of physical phenomena, such as local strain gradients stemming e.g.…”

Excitonic theory of doping-dependent optical response in atomically thin semiconductors

“…Concurrently, the simplicity of our theory allows further adaptations, for instance, to study the trion dynamics in optical wave mixing experiments [98][99][100][101][102] or photoluminescence [103][104][105][106] influenced by phonon-assisted relaxation phenomena [107,108]. Further perspectives could be to theoretically investigate the influence of doping on spatiotemporal dynamic effects not only in monolayer TMDCs [109][110][111][112][113][114][115][116] but also in other atomically thin semiconductors like hybrid perovskites [117][118][119].…”

Energy Dissipation and Decoherence in Solid-State Quantum Devices: Markovian versus non-Markovian Treatments

“…To overcome this severe limitation, a few years ago, an alternative and more general Markov procedure has been proposed [ 19 ]; the latter allows for a microscopic derivation of Lindblad-type scattering superoperators [ 11 ], thus preserving the positive-definite nature of the electronic density matrix. More recently, such an alternative Markov scheme combined with the conventional mean-field approximation has allowed for the derivation of a positive-definite nonlinear equation for the single-particle density matrix [ 20 , 21 ], able to describe both carrier–phonon and carrier–carrier interaction; the latter has been recently applied to the investigation of scattering nonlocality in GaN-based materials [ 22 ] and carbon nanotubes [ 23 ] as well as to the study of carrier capture processes [ 24 , 25 ].…”