skip to main content

SciTech ConnectSciTech Connect

Title: The formation mechanism for printed silver-contacts for silicon solar cells

Screen-printing provides an economically attractive means for making Ag electrical contacts to Si solar cells, but the use of Ag substantiates a significant manufacturing cost, and the glass frit used in the paste to enable contact formation contains Pb. To achieve optimal electrical performance and to develop pastes with alternative, abundant, and non-toxic materials requires understanding the contact formation process during firing. Here, we use in-situ X-ray diffraction during firing to reveal the reaction sequence. The findings suggest that between 500 degrees C and 650 degrees C PbO in the frit etches the SiNx antireflective-coating on the solar cell, exposing the Si surface. Then, above 650 degrees C, Ag+ dissolves into the molten glass frit -- key for enabling deposition of metallic Ag on the emitter surface and precipitation of Ag nanocrystals within the glass. Ultimately, this work clarifies contact formation mechanisms and suggests approaches for development of inexpensive, nontoxic solar cell contacting pastes.
 [1] ;  [2] ;  [2] ;  [3] ;  [2] ;  [1] ;  [2] ;  [1]
  1. National Renewable Energy Lab. (NREL), Golden, CO (United States)
  2. SLAC National Accelerator Lab., Menlo Park, CA (United States)
  3. Stanford Univ., CA (United States)
Publication Date:
OSTI Identifier:
Report Number(s):
Journal ID: ISSN 2041-1723
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Nature Communications
Additional Journal Information:
Journal Volume: 7; Related Information: Nature Communications; Journal ID: ISSN 2041-1723
Nature Publishing Group
Research Org:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Org:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Solar Energy Technologies Office (EE-4S)
Country of Publication:
United States
14 SOLAR ENERGY; 36 MATERIALS SCIENCE silicon photovoltaics; contact formation; in situ X-ray diffraction