Metal Insulator Semiconductor Solar Cells Based on SiGe Virtual Substrates
Ziyad A. Altarawneh |Pages: 268-288|

Abstract— Recent research works on fabrication technologies of efficient solar cells indicate that fabrication cost is a major hurdle in adopting such devices in large-scale terrestrial applications. The cost reduction of solar cells can potentially emerge from technological advancements in the production of solar cells by utilizing multicrystalline or amorphous semiconductors rather than the conventional single crystal semiconductor solar cell. The characteristics of homojunction solar cells have been closely examined; however, such devices have high dark currents. Other alternatives are Metal Insulator Semiconductor (MIS) solar cells. The Si-MIS structures are very simple to fabricate and can possibly provide efficient solar cells. In this paper, a novel approach to improve the overall performance of the Si-based MIS solar cells by utilizing the SiGe layer as a virtual substrate is proposed. Extensive TCAD simulations are undertaken to investigate the overall electrical performance of the SiGe-based MIS solar cells. The simulation results show that the SiGe based devices outperform their Si counterparts. The electrical efficiency has reached up to 22.6%. Finally, the proposed MIS device is optimized in accordance with the findings of the key design parameters that influence the electrical efficiency of the cell such as the ratio of Ge in the SiGe substrate, thickness of the SiGe layer and thickness of the silicon layer.