Passivation mechanism of the high-performance titanium oxide carrier-selective contacts on crystalline silicon studied by spectroscopic ellipsometry. (15th January 2021)

• Record Type: Journal Article
• Authors: Gotoh, Kazuhiro; Miura, Hiroyuki; Shimizu, Ayako; Kurokawa, Yasuyoshi; Usami, Noritaka
• Is Part Of: Japanese journal of applied physics. Volume 60:Number SB(2021)
• Publication Date: 2021-01-15
• Subjects: titanium oxide -- passivation -- optical properties -- silicon -- solar cell material; Physics -- Periodicals; 621.05
• DOI: 10.35848/1347-4065/abd6dd
• Languages: English
• ISSNs: 0021-4922

Abstract

Abstract: Variable-angle spectroscopic ellipsometry analysis is performed to study the impact of post-deposition annealing on the passivation performance of the heterocontacts consisting of titanium oxide and silicon oxide on crystalline silicon (c-Si) prepared by atomic layer deposition (ALD) for the development of high-performance ALD-TiO x /SiO y /c-Si heterocontacts. The highest lifetime of 1.8 ms is obtained for the TiO x /SiO y /c-Si heterocontacts grown at 175 °C after annealing at 275 °C for 3 min. With increasing annealing temperature, the TiO x layers of the TiO x /SiO y /c-Si heterocontacts become dominant. Furthermore, the amplitude of dielectric functions of the ALD-TiO x layer decreases as annealing temperature increases, which suggests that enhanced diffusion of Ti into SiO y interlayers at higher annealing temperature. The sufficient diffusion of Ti atoms into SiO y interlayers is caused by annealing at 275 °C for 3 min, yielding high-quality interface passivation.