{"681485":{"#nid":"681485","#data":{"type":"event","title":"Ph.D. Dissertation Defense - Keeya Madani","body":[{"value":"\u003Cp\u003E\u003Cstrong\u003ETitle\u003C\/strong\u003E\u003Cem\u003E:\u0026nbsp; Development and Fabrication of High Efficiency N-Type Tunnel Oxide Passivated Silicon Solar Cells with APCVD, Ion Implanted, and BBr3 Boron Emitters\u003C\/em\u003E\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003ECommittee:\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003EDr. Ajeet Rohatgi, ECE, Chair, Advisor\u003C\/p\u003E\u003Cp\u003EDr. Thomas Gaylord, ECE\u003C\/p\u003E\u003Cp\u003EDr. Juan-Pablo Correa-Baena, MSE\u003C\/p\u003E\u003Cp\u003EDr. Bruno Frazier, ECE\u003C\/p\u003E\u003Cp\u003EDr. Muhannad Bakir, ECE\u003C\/p\u003E","summary":"","format":"limited_html"}],"field_subtitle":"","field_summary":[{"value":"\u003Cdiv\u003EThis thesis focuses on developing cost-effective, high efficiency (~23%) n-type silicon solar cells utilizing tunnel oxide passivated contacts (TOPCon) on rear and optimized boron-doped emitters on front of a n-type Si wafer. Incorporating an ultra-thin tunnel oxide capped with doped poly-Si significantly reduces minority carrier recombination in the doped and metallized regions, enhancing efficiency without increasing costs. This research involves solar cell modelling, design, fabrication, and characterization of commercial-ready n-TOPCon solar cells. It also covers fundamental silicon solar cell principles, characterization tools, and a literature review on technology trends. First, a technology roadmap was developed with Quokka 2 device modelling to improve the baseline n-type p+\/n\/n+ PERT cell efficiency from 20.5% to 23% through a combination of front side boron emitter optimization, development and integration of rear side n-TOPCon, and improved screen-printed metal contacts. Three different B diffusion technologies, including APCVD, ion implantation, and BBr3 were investigated, optimized, and integrated into cell processing.\u003C\/div\u003E\u003Cdiv\u003E\u0026nbsp;\u003C\/div\u003E\u003Cdiv\u003EFabrication of large-area n-TOPCon cells resulted in 23.3% efficiency with BBr3 emitter followed by 22.7% for ion implantation and 22.2% for APCVD emitters. Detailed device characterization and modelling was performed on these cells to identify and quantify the loss mechanisms in these cells and a new technology roadmap is proposed to take n-TOPCon cell efficiencies to \u0026gt;= 25% by using higher quality Si wafers, ultra-high sheet resistance emitters, and improved metallization techniques. The research successfully developed high efficiency (~23%) commercial-ready n-TOPCon cells, setting a foundation for making photovoltaics the cheapest electricity source.\u003C\/div\u003E","format":"limited_html"}],"field_summary_sentence":[{"value":"Development and Fabrication of High Efficiency N-Type Tunnel Oxide Passivated Silicon Solar Cells with APCVD, Ion Implanted, and BBr3 Boron Emitters "}],"uid":"28475","created_gmt":"2025-03-31 23:00:49","changed_gmt":"2025-03-31 23:01:08","author":"Daniela Staiculescu","boilerplate_text":"","field_publication":"","field_article_url":"","field_event_time":{"event_time_start":"2025-04-07T15:00:00-04:00","event_time_end":"2025-04-07T17:00:00-04:00","event_time_end_last":"2025-04-07T17:00:00-04:00","gmt_time_start":"2025-04-07 19:00:00","gmt_time_end":"2025-04-07 21:00:00","gmt_time_end_last":"2025-04-07 21:00:00","rrule":null,"timezone":"America\/New_York"},"location":"Room W218, Van Leer","extras":[],"groups":[{"id":"434381","name":"ECE Ph.D. Dissertation Defenses"}],"categories":[],"keywords":[{"id":"100811","name":"Phd Defense"},{"id":"1808","name":"graduate students"}],"core_research_areas":[],"news_room_topics":[],"event_categories":[{"id":"1788","name":"Other\/Miscellaneous"}],"invited_audience":[{"id":"78771","name":"Public"}],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[],"email":[],"slides":[],"orientation":[],"userdata":""}}}