Optimization and characterization of i/p buffer layer in hydrogenated nanocrystalline silicon solar cells

• Published in: Journal of non-crystalline solids Vol. 354; no. 19-25; pp. 2440 - 2444
• Main Authors: Yue, Guozhen, Yan, Baojie, Teplin, Charles, Yang, Jeffrey, Guha, Subhendu
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 01.05.2008; Elsevier
• Subjects: Amorphous semiconductors; Applied sciences; CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; Cross-disciplinary physics: materials science; rheology; Energy; Exact sciences and technology; Materials science; Nanocrystalline materials; Nanoscale materials and structures: fabrication and characterization; Natural energy; Photovoltaic conversion; Physics; Silicon; Solar cells; Solar cells. Photoelectrochemical cells; SOLAR ENERGY; Solar cells; 68.05.Cf; Silicon; 61.82.Rx; Amorphous semiconductors; 61.43.Dq; Buffer layer; Amorphous semiconductors; Silicon; Solar cells; Inorganic compounds; Ge-Si alloys; 61.43.Dq; 61.82.Rx; 68.05.Cf; Optimization; Thin films; Thickness; Interfaces; Charge carrier recombination; Amorphous hydrogenated material; Nanocrystal
• ISSN: 0022-3093; 1873-4812
• DOI: 10.1016/j.jnoncrysol.2007.09.037

The effect of a-Si:H i/p buffer layer on the performance of nc-Si:H solar cells is studied systematically. The results show that for thin nc-Si:H cells, an optimized i/p buffer layer significantly reduces the dark current thus increases the open-circuit voltage. We believe that the carrier recombination at the i/p interface is one of the determining factors for the nc-Si:H cell performance, especially for cells with a thin intrinsic layer. Therefore, optimizing the i/p buffer layer is one of the key factors for achieving high efficiency nc-Si:H solar cells. This interface effect is less pronounced as the nc-Si:H intrinsic layer thickness increases, where the recombination in the bulk becomes a dominant factor. Combining the improved nc-Si:H intrinsic layer with a proper hydrogen dilution and an optimized a-Si:H i/p buffer layer, the performance of nc-Si:H single-junction and a-Si:H/a-SiGe:H/nc-Si:H triple-junction cells is significantly improved.