Atomic layer deposition TiO2 films and TiO2/SiNx stacks applied for silicon solar cells

Zu-Po Yang, Hsyi En Cheng, I. Hsuan Chang, Ing Song Yu*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

10 Scopus citations

Abstract

Titanium oxide (TiO2) films and TiO2/SiNx stacks have potential in surface passivation, anti-reflection coatings and carrier-selective contact layers for crystalline Si solar cells. A Si wafer, deposited with 8-nm-thick TiO2 film by atomic layer deposition, has a surface recombination velocity as low as 14.93 cm/s at the injection level of 1.0 × 1015 cm-3. However, the performance of silicon surface passivation of the deposited TiO2 film declines as its thickness increases, probably because of the stress effects, phase transformation, atomic hydrogen and thermal stability of amorphous TiO2 films. For the characterization of 66-nm-thick TiO2 film, the results of transmission electron microscopy show that the anatase TiO2 crystallinity forms close to the surface of the Si. Secondary ion mass spectrometry shows the atomic hydrogen at the interface of TiO2 and Si which serves for chemical passivation. The crystal size of anatase TiO2 and the homogeneity of TiO2 film can be deduced by the measurements of Raman spectroscopy and spectroscopic ellipsometry, respectively. For the passivating contacts of solar cells, in addition, a stack composed of 8-nm-thick TiO2 film and a plasma-enhanced chemical-vapor-deposited 72-nm-thick SiNx layer has been investigated. From the results of the measurement of the reflectivity and effective carrier lifetime, TiO2/SiNx stacks on Si wafers perform with low reflectivity and some degree of surface passivation for the Si wafer.

Original languageEnglish
Article number233
JournalApplied Sciences (Switzerland)
Volume6
Issue number8
DOIs
StatePublished - 19 Aug 2016

Keywords

  • Anatase
  • Antireflection coating
  • Atomic layer deposition
  • Carrier selective contact
  • Silicon solar cell
  • Surface passivation
  • Titanium oxide

Fingerprint Dive into the research topics of 'Atomic layer deposition TiO<sub>2</sub> films and TiO<sub>2</sub>/SiN<sub>x</sub> stacks applied for silicon solar cells'. Together they form a unique fingerprint.

Cite this