الفهرس | Only 14 pages are availabe for public view |
Abstract This thesis introduces modeling and analysis of solar cells and then focusing on the tandem solar cells. Tandem solar cell types and operation concept are given with its advantages and limitations. This thesis focusses on two terminal tandem solar cells. The design and results of testing four different top (Perovskite) sub-cells and four bottom sub-cells are given. The four top sub-cells are: perovskite (MAPbI3), perovskite (MAPbI3-xClx), carbon perovskite (MAPbI3), and electron transport layer free perovskite (MAPbI3-xClx). After those four bottom sub-cells were introduced based on using silicon, copper indium gallium selenide, germanium telluride, and two absorber sub-layers using both copper indium gallium selenide and germanium telluride materials with different doping levels to improve the voltage of the cell. It shows a good result as it is equivalent electrically to two seirsly connected, this shows a higher voltage and better performance. The two absorbers bottom sub-cell; have a limitation of current as the sub-layer with the minimum current density limits the sub-cell and in turn the tandem cell current density. Then a proposed solution of the current limitations of the two terminal tandem solar cells (current density must be the same of both sub-cells) is introduced based on using germanium telluride. As the bottom sub-cell is always the one with minimum current density that limits the overall tandem current density and the tandem cell efficiency. Germanium telluride bottom sub-cell shows a high current density which allows the top sub-cell to operate at a high current density value and in turn the tandem cell, this improves the tandem cell efficiency. Through this thesis sixteen different tandem cells were designed and tested. A new algorithm of optimizing the top sub-cell absorber layer is proposed. Also, a study of the tandem cell performance stability with temperature variations in the range (260°K to 360°K) is introduced. The designed tandem cells show different performance parameters with a promising result up to about 45% power conversion efficiency. |