Title :
C-Si surface passivation by aluminum oxide studied with electron energy loss spectroscopy
Author :
Hoex, B. ; Bosman, M. ; Nandakumar, Naomi ; Kessels, W.M.M.
Author_Institution :
Solar Energy Res. Inst. of Singapore (SERIS), Nat. Univ. of Singapore (NUS), Singapore, Singapore
Abstract :
In this work the mechanism of c-Si surface passivation by Al2O3 films is studied in detail by means of spatially resolved electron energy loss spectroscopy (EELS). The bonding configuration of Al and O is studied in as-deposited and annealed Al2O3 films grown on c-Si substrates by plasma-assisted and thermal atomic layer deposition (ALD). The ratio of tetrahedrally and octahedrally coordinated Al is found to increase after annealing, especially for the plasmaassisted ALD sample. The increase is strongest close to the c-Si/Al2O3 interface and thus these results strongly support tetrahedrally coordinated Al as the origin for the negative fixed charge in Al2O3.
Keywords :
aluminium compounds; annealing; atomic layer deposition; bonds (chemical); electron energy loss spectra; elemental semiconductors; passivation; plasma deposition; silicon; thin films; ALD; Al2O3; EELS; Si; aluminum oxide; annealing; bonding configuration; negative fixed charge; octahedrally coordinated Al; plasma-assisted deposition; spatially resolved electron energy loss spectroscopy; surface passivation; tetrahedrally coordinated Al; thermal atomic layer deposition; Aluminum oxide; Annealing; Energy loss; Films; Passivation; Physics; Silicon; aluminum oxide; electron energy loss spectroscopy; fixed charge; surface passivation;
Conference_Titel :
Photovoltaic Specialists Conference (PVSC), 2013 IEEE 39th
Conference_Location :
Tampa, FL
DOI :
10.1109/PVSC.2013.6745164
