Oxidation precursor dependence of atomic layer deposited Al2O3 films in a-Si:H(i)/Al2O3 surface passivation stacks
نویسندگان
چکیده
In order to obtain a good passivation of a silicon surface, more and more stack passivation schemes have been used in high-efficiency silicon solar cell fabrication. In this work, we prepared a-Si:H(i)/Al2O3 stacks on KOH solution-polished n-type solar grade mono-silicon(100) wafers. For the Al2O3 film deposition, both thermal atomic layer deposition (T-ALD) and plasma enhanced atomic layer deposition (PE-ALD) were used. Interface trap density spectra were obtained for Si passivation with a-Si films and a-Si:H(i)/Al2O3 stacks by a non-contact corona C-V technique. After the fabrication of a-Si:H(i)/Al2O3 stacks, the minimum interface trap density was reduced from original 3 × 10(12) to 1 × 10(12) cm(-2) eV(-1), the surface total charge density increased by nearly one order of magnitude for PE-ALD samples and about 0.4 × 10(12) cm(-2) for a T-ALD sample, and the carrier lifetimes increased by a factor of three (from about 10 μs to about 30 μs). Combining these results with an X-ray photoelectron spectroscopy analysis, we discussed the influence of an oxidation precursor for ALD Al2O3 deposition on Al2O3 single layers and a-Si:H(i)/Al2O3 stack surface passivation from field-effect passivation and chemical passivation perspectives. In addition, the influence of the stack fabrication process on the a-Si film structure was also discussed in this study.
منابع مشابه
Surface passivation and optical characterization of Al2O3/a-SiCx stacks on c-Si substrates
The aim of this work is to study the surface passivation of aluminum oxide/amorphous silicon carbide (Al2O3/a-SiCx) stacks on both p-type and n-type crystalline silicon (c-Si) substrates as well as the optical characterization of these stacks. Al2O3 films of different thicknesses were deposited by thermal atomic layer deposition (ALD) at 200 °C and were complemented with a layer of a-SiCx depos...
متن کاملPassivation mechanism of thermal atomic layer-deposited Al2O3 films on silicon at different annealing temperatures
Thermal atomic layer-deposited (ALD) aluminum oxide (Al2O3) acquires high negative fixed charge density (Qf) and sufficiently low interface trap density after annealing, which enables excellent surface passivation for crystalline silicon. Qf can be controlled by varying the annealing temperatures. In this study, the effect of the annealing temperature of thermal ALD Al2O3 films on p-type Czochr...
متن کاملNanoscale photon management in silicon solar cells
Related Articles Status and prospects of Al2O3-based surface passivation schemes for silicon solar cells J. Vac. Sci. Technol. A 30, 040802 (2012) Amorphous and nanocrystalline silicon thin film photovoltaic technology on flexible substrates J. Vac. Sci. Technol. A 30, 04D108 (2012) Room temperature atomic layer deposition of Al2O3 and replication of butterfly wings for photovoltaic application...
متن کاملInfluence of argon plasma on the deposition of Al2O3 film onto the PET surfaces by atomic layer deposition
In this paper, polyethyleneterephthalate (PET) films with and without plasma pretreatment were modified by atomic layer deposition (ALD) and plasma-assisted atomic layer deposition (PA-ALD). It demonstrates that the Al2O3 films are successfully deposited onto the surface of PET films. The cracks formed on the deposited Al2O3 films in the ALD, plasma pretreated ALD, and PA-ALD were attributed to...
متن کاملStatus and prospects of Al2O3-based surface passivation schemes for silicon solar cells
The reduction in electronic recombination losses by the passivation of silicon surfaces is a critical enabler for high-efficiency solar cells. In 2006, aluminum oxide (Al2O3) nanolayers synthesized by atomic layer deposition (ALD) emerged as a novel solution for the passivation of pand n-type crystalline Si (c-Si) surfaces. Today, high efficiencies have been realized by the implementation of ul...
متن کامل