Solar power generation (Solar system)・R&D for the production of next-generation spherical silicon solar cells Clean Venture 21

Technical Information About Spherical Silicon Solar Cells with Micro Reflector Cups

What are spherical silicon solar cells?

  • Productivity is high, as the silicon is melted and shaped into balls.
  • There’s no silicon cutting process, and thanks to the use of reflector cups, production costs are low because less silicon is necessary.
  • Due to the use of crystalline silicon, conversion efficiency is high and there is no degradation from exposure to sunlight.
  • As the substrate is made from aluminum, it is both unbreakable and bendable.
Optical simulation

Development Concept

Comparison with conventional wafer-based silicon solar cells:


  • Production costs are less than 1/5
  • Silicon raw material per 1 W is less than 1/5
  • Energy consumption by manufacturing processes is less than 1/2
  • Comparable performance and reliability are achieved.
  • Flexible modules are realized.
結晶系シリコン太陽電池

Basic technologies for higher efficiency of spherical silicon solar cells with micro reflector cups

  • Higher crystallization of silicon balls
  • Introduction of light-trapping texture
  • Introduction of bulk passivation that renders defects inert
  • Reduction of surface combinations by surface passivation
  • Reduction of conductive AR film resistivity
  • Improvement of light-concentrating ratio by optimization of reflectors in a substrate
集光型球状太陽電池