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Interface analysis of ultrathin SiO 2 layers between c‐Si substrates and phosphorus‐doped poly‐Si by theoretical surface potential analysis using the injection‐dependent lifetime
Author(s) -
Choi Sungjin,
Baek Jimin,
Kim Taejun,
Min Kwan Hong,
Jeong Myeong Sang,
Song Heeeun,
Kang Min Gu,
Kim Donghwan,
Kang Yoonmook,
Lee HaeSeok,
Myoung JaeMin,
Park Sungeun
Publication year - 2021
Publication title -
progress in photovoltaics: research and applications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.286
H-Index - 131
eISSN - 1099-159X
pISSN - 1062-7995
DOI - 10.1002/pip.3338
Subject(s) - passivation , materials science , polycrystalline silicon , silicon , doping , wafer , oxide , carrier lifetime , dopant , solar cell , crystalline silicon , optoelectronics , silicon oxide , analytical chemistry (journal) , layer (electronics) , nanotechnology , chemistry , metallurgy , thin film transistor , chromatography , silicon nitride
Passivated contact structures are often representative of tunnel oxide passivated contact (TOPCon) and polycrystalline silicon on oxide (POLO) solar cells. These passivated contact technologies in silicon solar cells have experienced great strides in efficiency. However, characteristics analysis of poly‐Si/SiO 2 applied to TOPCon and POLO solar cells as a carrier‐selective and passivated contact is still challenging because the silicon oxide film is very thin (<1.5 nm), poly‐Si and silicon oxide properties change during thermal treatment for passivation effects, and dopant diffusion from poly‐Si layer to the silicon wafer occurs. In this study, the interfacial analysis was performed by applying an algorithm based on the extended Shockley–Read–Hall (SRH) theory to the P‐doped poly‐Si/SiO 2 /c‐Si structure. Quantitative parameters of the P‐doped poly‐Si/SiO 2 /c‐Si interface were extracted by fitting the measured and simulated lifetime curves with algorithms, such as D it (interface trap density) and Q f (fixed charge), from which we were able to elucidate the passivation effect of the interface. The interface analysis method using this algorithm is meaningful in that it can quantify the passivation characteristics of TOPCon with very thin silicon oxide film. The interface characteristics were also analyzed using the injection‐dependent lifetime after thermal treatment of P‐doped poly‐Si/SiO 2 /c‐Si samples for passivation effect. After the 850°C thermal treatment, the following best passivation effects were verified, namely, ψ s = 0.248 eV, D it = 1.0 × 10 11 cm −2 ·eV −1 , Q f = 2.4 × 10 12 cm −2 , and J 02 = 370 pA·cm −2 . Through the analysis model using carrier lifetime theory, we investigated quantitatively the passivation properties of P‐doped poly‐Si/SiO 2 /c‐Si.