One-step Electrochemical Deposition of a Dense, Photoresponsive Silicon Film on Graphite

Physical Sciences : Materials and Compounds

Available for licensing

Inventors

  • Allen Bard, Ph.D. , Chemistry and Biochemistry
  • Huayi Yin , University of Texas at Austin

Background/unmet need

A low-cost process of producing highly photoresponsive silicon (Si) is crucial for cutting the cost of current methods. Direct electrochemical deposition of photoresponsive Si has been demonstrated on a silver substrate in molten CaCl2 containing SiO2 nanoparticles. However, the high cost of silver and the porosity of the deposited Si call for a new substrate and a controllable approach. Moreover, the use of silver constrains the applied electrochemical potential window of the electrolysis.

Invention Description

In this invention, a low-cost carbon substrate--e.g., graphite--was employed to deposit photoresponsive Si, with porosity more comparable to that of commercial Si wafer. The use of graphite substrate reduces process cost and produces a very dense Si film. Additionally, graphite substrate allows a wider potential and/or current density tunable range in the electrochemical deposition process, so the morphology of the Si deposit can be better engineered. Si deposits of different morphologies such as Si nanowires, nanoparticles and dense films can also be prepared on a graphite substrate. Besides graphite, other carbonaceous materials, such as active carbon, carbon fiber, carbon nanotubes, can be used as substrate or template for producing photoresponsive Si.

Benefits/Advantages

  • Low-cost one-step approach, with low energy consumption
  • Fewer byproducts and ease of scale-up
  • Better process control through potential and/or current density tuning

Features

  • One step process of preparing a dense and photoresponsive Si film and Si nanowires on a carbon substrate
  • No need for Si refining as in current process
  • Electrodeposition conducted in CaCl2-SiO2 melt, using low-cost carbon substrate

Market potential/applications

Photovoltaic industry; silicon substrate/wafer industry; anode material for lithium-ion batteries

Development Stage

Lab/bench prototype

IP Status

  • 1 U.S. patent application filed