Evaluation of Sn-Doped Indium Oxide Film and Interface Properties on a-Si Formed by Reactive Plasma Deposition

Result of the Month

HAXPES Si 1s Spectra Before and After PDA | © Prof. Atsushi Ogura
HAXPES Si 1s spectra before and after PDA. The spectrum is around 1839 eV due to Si-Si bond, around 1844 eV due to SiOx bond.
Graph showing the Si 1s spectrum of the SiO2 (30 nm) | © Prof. Atsushi Ogura
Figure shows the Si 1s spectrum of the SiO2 (30 nm)/Si sample as a reference. Since there are few reference in the Si 1s spectrum so far, each spectrum was identified by measuring a sample with a known sample structure. The sample structure has been confirmed by spectroscopic ellipsometry.

Author: Prof. Atsushi Ogura Institute: ''Meiji University, Tama-ku, Kawasaki, Kanagawa 214-8571, Japan'' ECS Journal of Solid State Science and Technology
URL: http://jss.ecsdl.org/content/8/6/Q101.full
Date: 10/2019
Instruments: HAXPES Lab

Aiming to improve the performance of heterojunction Si solar cells, we evaluated the Sn-doped indium oxide (ITO) / a-Si structure using conventional and hard X-ray photoelectron spectroscopy (XPS, HAXPES), and the cause of the solar cell performance Identified deterioration. HAXPES allows non-destructive evaluation of the SiOx layer at the ITO / a-Si interface. The formation of SiOx at the ITO / a-Si interface increases the contact resistance, which can be reduced by post-deposition annealing (PDA). In addition, PDA facilitated Fermi level evaluation, ITO component precipitation in the a-Si layer, and increased interface roughness. Before the PDA, diffusion of a-Si Sn atoms was observed. In addition, PDA confirmed that Si atoms diffused into ITO. These reactions at the ITO / a-Si interface may be part of the deterioration factor of Si solar cells.


Tappei Nishiahra1, Takefumi Kamioka1, Hiroki Kanai1, Yoshio Ohshita2, Satoshi Yasuno3, Ichiro Hirosawa3, and Atsushi Ogura1


1) Meiji University

2) Toyota Technological Institute


Name and email of corresponding author

Tappei Nishiara; ce181053@meiji.ac.jp

Atushi Ogura; a_ogura@meiji.ac.jp

URL of Institute web-pages



ECS Journal of Solid State Science and Technology, 8, Q101 (2019).