Solar Photovoltaic Manufacturing Value Chain

The solar photovoltaic manufacturing value chain converts polysilicon into electricity-producing PV modules through a sequence of material-processing and assembly stages. Its core progression is polysilicon to ingot, wafer, solar cell and finished module, with each stage adding technological complexity and value.

Polysilicon to ingots and wafers

The upstream stage converts purified silicon feedstock into the thin substrates on which photovoltaic cells are fabricated.

• Polysilicon is melted and crystallised under controlled conditions to produce monocrystalline ingots or multicrystalline blocks.
• The solid silicon is shaped and sliced by precision wire sawing into thin wafers, which are then cleaned and inspected.
• Sawing losses and wafer thickness influence material use, manufacturing cost and production efficiency.

Wafers to photovoltaic cells

A wafer becomes a solar cell when semiconductor processing enables it to absorb sunlight and generate direct current electricity.

• The wafer surface is cleaned and textured to improve light absorption.
• Controlled doping creates a p-n junction, which separates charge carriers generated by sunlight.
• Passivation and antireflection layers reduce electrical and optical losses.
• Metal contacts are applied so that the generated electricity can be collected and conducted outside the cell.

Cells to finished modules

Module manufacturing electrically connects cells and packages them to withstand outdoor operation.

• Cells are tested, sorted and interconnected into cell strings using conductive ribbons.
• The strings are laid between protective layers, commonly including front glass, encapsulant and a backsheet or rear glass, and are then laminated.
• An aluminium frame, junction box and cables are added where required.
• The finished module undergoes visual, electrical, insulation and performance testing before dispatch.