Physics-Based Modeling and Experimental Study of Si-Doped InAs/GaAs Quantum Dot Solar Cells

Abstract

This paper presents an experimental and theoretical study on the impact of doping and recombination mechanisms on quantum dot solar cells based on the InAs/GaAs system. Numerical simulations are built on a hybrid approach that includes the quantum features of the charge transfer processes between the nanostructured material and the bulk host material in a classical transport model of the macroscopic continuum. This allows gaining a detailed understanding of the several physical mechanisms affecting the photovoltaic conversion efficiency and provides a quantitatively accurate picture of real devices at a reasonable computational cost. Experimental results demonstrate that QD doping provides a remarkable increase of the solar cell open-circuit voltage, which is explained by the numerical simulations as the result of reduced recombination loss through quantum dots and defects.

Optical absorption spectra of GaSb/GaAs quantum-ring-with-dot structures and their potential for intermediate band solar cells

“…The radiative lifetimes τ r,R = 12 ns, τ r,D = 15 ns and τ r,W = 1 µs are for the QRs, QDs and GaSb layer, respectively [26]. Due to the lack of Shockley-Read-Hall (SRH) lifetime data of the QRDSs, the influence of non-radiative recombination in each QRDS layer will be effectively included in the GaAs region by using the SRH model [46]. Even though the photogenerated holes in the GaSb layer are rapidly captured by the QRs and/or QDs [26], the PL emission from the GaSb layer is still observable at high temperatures [24].…”

Reduced Dimensionality Multiphysics Model for Efficient VCSEL Optimization

“…D1ANA is based on the same quantum-corrected drift-diffusion model presented in [10,11,[30][31][32], thus it solves in a self-consistent fashion the Poisson's equation with the carrier continuity equations. Fermi-Dirac statistics are used to describe electron and hole densities [33][34][35], together with the incomplete ionization model of the dopants [36,37].…”

Simulating quantum dot intermediate band solar cells by enhanced semiclassical model

“…Here, the Poisson-drift-diffusion transport model is coupled to rate equations describing the interband and intersubband charge transfer mechanisms involving the QD states. We have previously used this model, with experimental based parameters, to elucidate some mechanisms in thermally limited QD cells made of InAs/GaAs self-assembled QDs, such as the role of non-radiative recombination, doping, and wetting layer [11], [12], [13].…”