Efficient Passivation of N-Type and P-Type Silicon Surface Defects by Hydrogen Sulfide Gas Reaction

Document Type

Article

Publication Date

9-3-2021

Publication Title

Journal of Physics Condensed Matter

Volume

33

First page number:

1

Last page number:

8

Abstract

An efficient surface defect passivation is observed by reacting clean Si in a dilute hydrogen sulfide-argon gas mixture ( < 5% H2S in Ar) for both n-type and p-type Si wafers with planar and textured surfaces. Surface recombination velocities of 1.5 and 8 cm s-1 are achieved on n-type and p-type Si wafers, respectively, at an optimum reaction temperature of 550 C that are comparable to the best surface passivation quality used in high efficiency Si solar cells. Surface chemical analysis using x-ray photoelectron spectroscopy shows that sulfur is primarily bonded in a sulfide environment, and synchrotron-based soft x-ray emission spectroscopy of the adsorbed sulfur atoms suggests the formation of S-Si bonds. The sulfur surface passivation layer is unstable in air, attributed to surface oxide formation and a simultaneous decrease of sulfide bonds. However, the passivation can be stabilized by a low-temperature (300 °C) deposited amorphous silicon nitride (a-Si:N X :H) capping layer.

Keywords

Hydrogen sulfide reaction; Silicon; Surface passivation; X-ray emission spectroscopy; X-ray photoelectron spectroscopy

Disciplines

Electromagnetics and Photonics

Language

English


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