A Low Resistance Calcium/Reduced Titania Passivated Contact for High Efficiency Crystalline Silicon Solar Cells. Issue 12 (3rd February 2017)

• Record Type: Journal Article
• Authors: Allen, Thomas G.; Bullock, James; Jeangros, Quentin; Samundsett, Christian; Wan, Yimao; Cui, Jie; Hessler‐Wyser, Aïcha; De Wolf, Stefaan; Javey, Ali; Cuevas, Andres
• Is Part Of: Advanced energy materials. Volume 7:Issue 12(2017)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2017-02-03
• Subjects: calcium -- passivated contacts -- PERC -- solar cells -- TiO2; Energy harvesting -- Materials -- Periodicals; Energy conversion -- Materials -- Periodicals; Energy storage -- Materials -- Periodicals; Photovoltaics -- Periodicals; Fuel cells -- Periodicals; Thermoelectric materials -- Periodicals; 621.31
• DOI: 10.1002/aenm.201602606
• Languages: English
• ISSNs: 1614-6832

Abstract

Abstract : Recent advances in the efficiency of crystalline silicon (c‐Si) solar cells have come through the implementation of passivated contacts that simultaneously reduce recombination and resistive losses within the contact structure. In this contribution, low resistivity passivated contacts are demonstrated based on reduced titania (TiO x ) contacted with the low work function metal, calcium (Ca). By using Ca as the overlying metal in the contact structure we are able to achieve a reduction in the contact resistivity of TiO x passivated contacts of up to two orders of magnitude compared to previously reported data on Al/TiO x contacts, allowing for the application of the Ca/TiO x contact to n‐type c‐Si solar cells with partial rear contacts. Implementing this contact structure on the cell level results in a power conversion efficiency of 21.8% where the Ca/TiO x contact comprises only ≈6% of the rear surface of the solar cell, an increase of 1.5% absolute compared to a similar device fabricated without the TiO x interlayer. Abstract : A novel passivated contact on crystalline silicon comprised of calcium and reduced titania is shown to result in a reduction in contact resistivity by up to two orders of magnitude compared to other titania‐based contacts to crystalline silicon. This enables the fabrication of a first‐of‐its‐kind passivated contact n‐type c‐Si PERC cell with an efficiency of 21.8%.