Theoretical and Numerical Investigation of InAs/GaAs Quantum Dot Solar Cell to Improve the Power Conversion Effciency
No Thumbnail Available
Date
2024-05
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Addis Ababa University
Abstract
The concept of introducing an intermediate band to overcome the e ciency limit of single-bandgap solar cells was proposed by Luque and Mart in 1997. It is predicted that utilising the intermediate band for multi-photon absorption can signi cantly improve the pho-tocurrent generation without accompanying output voltage loss. Quantum dots (QDs) have been proposed as a means for implementing intermediate band solar cells (IBSCs) to absorb low energy photons, due to their quantum con nement of carriers. The work reported in this thesis is concerned with the theoretical and numerical investigation of quantum dot solar cell (QDSC) using InAs QD multi-layers embedded in the i-region of a GaAs n+ i p+ structure. In particular, the dependence of QDSC parameters on the number of QD layers, QD size, and size dispersion and the impact of inserting InAs QD multi-layers in the middle subcell of Ga0:51In0:49P=GaAs=Ge triple-junction quantum dot solar cell (3J-QDSC). Numerical simulations show that, the solar cell parameters are strongly dependent on the number of QD layers, the average size and size dispersion of QDs. A maximum e ciency is obtained at optimum number of QD layers, QD size, and size dispersion. Above or below this optimal value degrades the e ciency of QDSC.
The current density-voltage characteristics have been simulated and discussed for triple junction solar cell with and without InAs QD. Inserting InAs QDs increases the short circuit current and e ciency of 3J-QDSC (40.1% ) with small degradation in open circuit voltage. In general, inserting optimized size, size dispersion, number of InAs QD layers in the i-region of a GaAs solar cell as well as in the middle subcell of triple-junction Ga0:51In0:49P=GaAs=Ge solar cell improves both the short circuit current density and the eciency of the solar cell with a small degradation in open circuit voltage.
Description
Keywords
Theoretical and Numerical, Investigation of InAs/GaAs, Quantum Dot Solar, Improve the Power, Conversion Effciency