[14a-PB7-1~14] 16 Amorphous and Microcrystalline Materials

[14a-PB7-7] Improvement of Crystalline Silicon Solar Cells by Use of Nitric Acid Oxidation Layer

〇Taketoshi Matsumoto¹, Hiroki Nakajima¹, Daichi Irishika¹, Takaaki Nonaka¹, Kentaro Imamura¹, Hikaru Kobayashi¹ (1.ISIR, Osaka Univ., CREST-JST)

Keywords:silicon,solar cell,nitric acid

By insertion of an ultrathin nitric acid oxidation of Si (NAOS) layer between an SiN/Si interface, energy conversion efficiencies of p- and n-type crystalline Si solar cells increased from 17.2 to 18.9% and from 16.6 to 17.5%, respectively, because of the passivation with elimination of interface states. Thermal oxidation after forming a NAOS layer improved the minority carrier lifetime from 11μs to 11 ms drastically. Various mechanisms will be discussed including protection of an SiN/Si interface during SiN deposition and removal of a highly-doped layer.