MNRE Plan for Domestic Polysilicon Manufacturing Scheme

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Key takeaways

The MNRE is formulating a scheme to set up 30 GW of domestic polysilicon manufacturing capacity in India by 2030.
Polysilicon serves as the primary raw material for making solar photovoltaic wafers, computer chips, and electronic circuits.
Solar-grade polysilicon requires 99.9999% to 99.9999999% purity, while electronic-grade silicon demands up to 99.999999999% purity.
Manufacturing relies on high-temperature reduction of silica sand followed by purification via the Siemens process or Fluidized Bed Reactor (FBR) tech.

The Ministry of New and Renewable Energy (MNRE) is planning a new financial subsidy scheme. This scheme aims to build 30 GW of domestic polysilicon manufacturing capacity in India by 2030.

Polycrystalline silicon or polysilicon is a highly refined crystalline form of elemental silicon. It consists of many tiny crystal grains joined together along internal boundaries.
This material acts as the core raw material for making solar wafers and semiconductor microchips. Without it, companies cannot manufacture solar panels or computer chips.

Mined quartz or silica sand is mixed with carbon sources like coke in a furnace at 1,900 degree C. This process produces metallurgical silicon with 98% to 99% purity.
Workers grind this metallurgical silicon into powder and react it with hydrogen chloride gas at high heat. This reaction creates volatile compounds like trichlorosilane.
The liquid trichlorosilane goes through multi-stage fractional distillation. This step removes tiny traces of unwanted metals, boron, and phosphorus impurities.
Manufacturers feed the purified chemical with hydrogen into high-temperature reactors using the Siemens process to deposit pure polysilicon onto heated rods. Alternatively, Fluidized Bed Reactor (FBR) technology produces silicon beads while consuming less energy.

Polysilicon requires extreme purity, categorized as solar grade with 6N to 9N purity or electronic grade reaching 9N to 11N purity with less than 1 part per billion (ppb) impurities.
Producing polysilicon requires huge financial investment and uninterrupted electrical power. Factories must maintain high furnace temperatures and run complex chemical recycling systems continuously.
Its natural electronic properties allow it to absorb sunlight and convert photon energy into electricity. This photovoltaic effect makes polysilicon an ideal semiconductor base.
Polysilicon has multiple internal crystal grains with random alignments. Manufacturers melt and process it using the Czochralski process to form single-crystal monocrystalline silicon ingots.

Factories cut polysilicon ingots into thin wafers to make mono-PERC, TOPCon, and heterojunction (HJT) solar cells used in commercial solar panels.
It serves as the core feedstock to manufacture microprocessors, DRAM and NAND memory chips, and microcontrollers for electronic computers and devices.
High-power electronic components like MOSFETs and diodes rely on polysilicon. These components regulate high-voltage electrical currents in electric vehicles and power grids.
In thin-film form, polysilicon helps manufacture high-resolution AMOLED and LCD screens for modern smartphones, televisions, and electronic displays.