Atomic-layer-deposited（ALD） aluminum oxide（Al2O3） has demonstrated an excellent surface passivation for crystalline silicon（c-Si） surfaces, as well as for highly boron-doped c-Si surfaces. In this paper, water-b...Atomic-layer-deposited（ALD） aluminum oxide（Al2O3） has demonstrated an excellent surface passivation for crystalline silicon（c-Si） surfaces, as well as for highly boron-doped c-Si surfaces. In this paper, water-based thermal atomic layer deposition of Al2O3 films are fabricated for c-Si surface passivation. The influence of deposition conditions on the passivation quality is investigated. The results show that the excellent passivation on n-type c-Si can be achieved at a low thermal budget of 250℃ given a gas pressure of 0.15 Torr. The thickness-dependence of surface passivation indicates that the effective minority carrier lifetime increases drastically when the thickness of Al2O3 is larger than 10 nm. The influence of thermal post annealing treatments is also studied. Comparable carrier lifetime is achieved when Al2O3 sample is annealed for 15 min in forming gas in a temperature range from 400℃ to 450℃. In addition, the passivation quality can be further improved when a thin PECVD-SiNx cap layer is prepared on Al2O3, and an effective minority carrier lifetime of2.8 ms and implied Voc of 721 mV are obtained. In addition, several novel methods are proposed to restrain blistering.展开更多
基金Project supported by the Beijing Municipal Science and Technology Commission,China(Grant No.Z151100003515003)the National Natural Science Foundation of China(Grant Nos.110751402347,61274134,51402064,61274059,and 51602340)+3 种基金the University of Science and Technology Beijing(USTB)Start-up Program,China(Grant No.06105033)the Beijing Municipal Innovation and Research Base,China(Grant No.Z161100005016095)the Fundamental Research Funds for the Central Universities,China(Grant Nos.FRF-UM-15-032 and 06400071)the Youth Innovation Promotion Association of Chinese Academy of Sciences(Grant No.2015387)
文摘Atomic-layer-deposited（ALD） aluminum oxide（Al2O3） has demonstrated an excellent surface passivation for crystalline silicon（c-Si） surfaces, as well as for highly boron-doped c-Si surfaces. In this paper, water-based thermal atomic layer deposition of Al2O3 films are fabricated for c-Si surface passivation. The influence of deposition conditions on the passivation quality is investigated. The results show that the excellent passivation on n-type c-Si can be achieved at a low thermal budget of 250℃ given a gas pressure of 0.15 Torr. The thickness-dependence of surface passivation indicates that the effective minority carrier lifetime increases drastically when the thickness of Al2O3 is larger than 10 nm. The influence of thermal post annealing treatments is also studied. Comparable carrier lifetime is achieved when Al2O3 sample is annealed for 15 min in forming gas in a temperature range from 400℃ to 450℃. In addition, the passivation quality can be further improved when a thin PECVD-SiNx cap layer is prepared on Al2O3, and an effective minority carrier lifetime of2.8 ms and implied Voc of 721 mV are obtained. In addition, several novel methods are proposed to restrain blistering.
