A Transfer Hamiltonian Model for Devices Based on Quantum Dot Arrays

Abstract

We present a model of electron transport through a random distribution of interacting quantum dots embedded in a dielectric matrix to simulate realistic devices. The method underlying the model depends only on fundamental parameters of the system and it is based on the Transfer Hamiltonian approach. A set of noncoherent rate equations can be written and the interaction between the quantum dots and between the quantum dots and the electrodes is introduced by transition rates and capacitive couplings. A realistic modelization of the capacitive couplings, the transmission coefficients, the electron/hole tunneling currents, and the density of states of each quantum dot have been taken into account. The effects of the local potential are computed within the self-consistent field regime. While the description of the theoretical framework is kept as general as possible, two specific prototypical devices, an arbitrary array of quantum dots embedded in a matrix insulator and a transistor device based on quantum dots, are used to illustrate the kind of unique insight that numerical simulations based on the theory are able to provide.

Design and fabrication of CuInS2/ZnS-based QLED for automotive lighting systems

“…48 Furthermore, using that approach the whole system can be described as independent subsystems connected by a transmission probability through the dielectric media. 42 Generally, for a more complex system, it is possible to define the current flowing between two parts (i,j ) of the latter. Assuming no inelastic scattering and symmetry in the transmission coefficient, 40 the net current flux between two parts of the system can be written as…”

“…Where both ρ i (E) and n i (E) are the density of states (DOS) and the energy distribution functions (unknown) for each layer (i) respectively. 42 For the sake of clarity and following Illera et al work, the energy distribution function for each layer (i) from the QLED will be defined as n i (E), while f L (E) and f R (E) will be reserved for the energy distribution function of the left and right electrodes. Then, it is possible to write the evolution of the charge over time as follows 40…”

“…where γ is the broadening of the level and it is related to the tunnel probabilities. 42,45 Transport layers. It is necessary to make the same study for the transport layer to conform the whole QLED system.…”

Elastic tunneling charge transport mechanisms in silicon quantum dots /SiO2 thin films and superlattices

“…25 A detailed explanation of the methodology can be found in Ref. 46 and its application to realistic Qds described with ab initio techniques is presented in Ref. 47.…”

“…48 All the parameters needed to describe the Si Qds array embedded in SiO 2 were extracted from Ref. 46. All the simulations were carried out at room temperature (k B T ¼ 0:026 eV).…”