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Dopant‐Free Partial Rear Contacts Enabling 23% Silicon Solar Cells
Author(s) -
Bullock James,
Wan Yimao,
Hettick Mark,
Zhaoran Xu,
Phang Sieu Pheng,
Yan Di,
Wang Hanchen,
Ji Wenbo,
Samundsett Chris,
Hameiri Ziv,
Macdonald Daniel,
Cuevas Andres,
Javey Ali
Publication year - 2019
Publication title -
advanced energy materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.08
H-Index - 220
eISSN - 1614-6840
pISSN - 1614-6832
DOI - 10.1002/aenm.201803367
Subject(s) - materials science , passivation , doping , dopant , annealing (glass) , silicon , solar cell , optoelectronics , crystalline silicon , sintering , nanotechnology , engineering physics , composite material , layer (electronics) , engineering
Over the past five years, there has been a significant increase in both the intensity of research and the performance of crystalline silicon devices which utilize metal compounds to form carrier‐selective heterocontacts. Such heterocontacts are less fundamentally limited and have the potential for lower costs compared to the current industry dominating heavily doped, directly metalized contacts. A low temperature (≤230 °C), TiO x /LiF x /Al electron heterocontact is presented here, which achieves mΩcm 2 scale contact resistivities ρ c on lowly doped n‐type substrates. As an extreme demonstration of the potential of this heterocontact, it is trialed in a newly developed, high efficiency n‐type solar cell architecture as a partial rear contact (PRC). Despite only contacting ≈1% of the rear surface area, an efficiency of greater than 23% is achieved, setting a new benchmark for n‐type solar cells featuring undoped PRCs and confirming the unusually low ρ c of the TiO x /LiF x /Al contact. Finally, in contrast to previous versions of the n‐type undoped PRC cell, the performance of this cell is maintained after annealing at 350–400 °C, suggesting its compatibility with conventional surface passivation activation and sintering steps.