Solar Photovoltaic Quartz at the Foundation of Every Solar Cell

Quartz glass is consumed at five distinct stages of solar manufacturing — polysilicon production, ingot growth, wafering, cell processing, and module assembly. Each stage places different demands on purity, geometry, and thermal performance. FGQuartz supplies the high-purity fused silica consumed across the entire chain, from Siemens reactor bell jars through to PECVD deposition components.

FGQuartz supplies high-purity fused silica across the full photovoltaic manufacturing chain — from the crucibles that grow silicon ingots to the process tubes, wafer carriers, liners and handling tools used in cell fabrication. Standard items ship from stock in 7–14 days; custom components matched to specific furnace platforms and ingot sizes are produced at Lianyungang in 3–6 weeks. For the full engineering background, see our solar photovoltaic quartz guide.

Czochralski quartz crucibles contain molten polysilicon above 1414°C during monocrystalline ingot pulling — a 12–40 hour pull — while releasing controlled oxygen into the melt. Produced in 12″–32″ diameters for single-pull and continuous-feed (CF-CZ) pullers, with standard, low-oxygen and high-oxygen inner-surface treatments.

12″–32″ · Single-pull & CF-CZ · Oxygen-controlled inner surface

View quartz crucibles →

Square crucibles for directional-solidification casting of multicrystalline and cast-mono ingots. Single-use — they bond to the ingot and are broken away after cooling. Produced in G5 (800×800 mm), G6, G7 and G8 (1300×1300 mm) sizes with seed-holder configurations for cast-mono production.

G5 / G6 / G7 / G8 · Single-use casting · Cast-mono compatible

View quartz crucibles →

Clear fused-silica tubes for POCl₃ / PH₃ emitter diffusion at 800–900°C, forming the n-type emitter of the p-n junction. Low metallic-impurity grade prevents the iron, chromium and nickel contamination that lowers cell efficiency. Matched to Centrotherm, Amtech, Tempress and Kokusai furnaces.

POCl₃ / PH₃ · Clear fused silica · Centrotherm / Amtech fit

View quartz tubes →

Slotted carriers that hold solar wafers vertically through diffusion, oxidation and annealing, spacing them so gas reaches both faces. Straight-slot and V-groove configurations for M2, M4, M6, M10 (182 mm) and G12 (210 mm), with controlled slot pitch and bow for diffusion uniformity at high throughput.

M10 (182 mm) · G12 (210 mm) · Straight & V-groove

View wafer boats →

Bell jars, process tubes, liners and carriers for SiNₓ anti-reflection deposition and TOPCon tunnel-oxide / poly-Si LPCVD. Clear and opaque fused silica that survives reactive plasma chemistry and repeated thermal cycling in PERC, TOPCon and HJT cell lines.

PECVD bell jars · LPCVD tubes · TOPCon & PERC

View custom quartz →

Clear and opaque liners that protect ceramic heating elements from chlorinated cleaning gases (TCA, HCl) and provide thermal insulation between process tube and heater, reducing temperature gradients and improving diffusion uniformity across the wafer load.

Clear & opaque · Single & multi-zone · TCA / HCl compatible

View quartz tubes →

High-purity solid and hollow rods and flat-blade paddles that load and extract wafer boats from tube furnaces. Made from high-purity fused silica because they enter the furnace and can deposit contamination, with end designs that engage standard boat lug and groove patterns.

Solid & hollow rods · Flat-blade paddles · Custom lengths

View quartz rod →

Fusion-welded quartz tanks for KOH/NaOH texturing and RCA-type cleaning, used specifically to avoid recontaminating wafers with boron or alkali metals that borosilicate tanks would leach. Overflow-weir, single-tank and cascade rinse designs with integrated drain and heating fittings.

Fusion-welded · Overflow weir · Rinse & acid baths

View custom quartz →

Custom quartz parts for TOPCon, HJT, IBC and perovskite-tandem equipment that does not exist in any catalogue. We accept DXF, STEP and IGES drawings and produce parts by CNC machining, oxy-hydrogen flame welding and precision grinding — research-scale prototypes to production volume.

DXF / STEP / IGES · TOPCon & HJT parts · Prototype to volume

View custom quartz →

Different solar process steps need different fused-silica grades. Diffusion and oxide tubes use clear fused silica. Furnace liners use opaque grade for thermal insulation. Optical and inspection windows use UV-grade fused silica. The grades FGQuartz supplies into solar manufacturing are summarised below.

Exact specifications are confirmed per process step. Custom grades available on request. See full data on our technical specifications page.

CZ crucibles are produced by arc fusion — electrically fused from high-purity quartz sand in a rotating mould, giving a dense, bubble-free inner layer and a more porous outer layer. The inner-surface condition, which governs both mechanical survival in the melt and the oxygen dissolution rate, is controlled during fusion and a subsequent surface-treatment step matched to standard, low-oxygen or high-oxygen targets.

Process tubes are produced by CNC precision grinding from high-purity fused-silica stock. Outer diameter, inner diameter and wall-thickness uniformity are monitored and documented for each run; tube ends are ground flat and square for flange mating. Inner-bore surface quality is controlled through the grinding and polishing sequence to meet the contamination sensitivity of each step.

Boats are machined from fused-silica blocks by CNC multi-axis machining. Slot cutting uses diamond-coated end mills on programmed tool paths that hold slot-pitch uniformity across the full boat length; bow is controlled through raw-material selection and machining strategy. Finished boats are inspected for slot dimensions, bow and surface-defect level before packaging.

FGQuartz supplies components for the full range of current and next-generation cell technologies — from standard BSF and multicrystalline cells through to TOPCon, HJT, multi-junction and perovskite-silicon tandem designs.

Passivated Emitter and Rear Cell technology remains the dominant architecture in global solar manufacturing. PERC cells require quartz across every thermal step — CZ crucibles for ingot growth, diffusion tubes and wafer boats for emitter formation, PECVD parts for SiNₓ and rear passivation, and tube hardware for oxide layers. FGQuartz stocks the most commonly consumed PERC items for rapid supply.

Tunnel oxide passivated contact technology achieves higher efficiency than PERC by passivating the rear contact with an ultra-thin tunnel oxide and doped polysilicon. The added tunnel-oxide growth and LPCVD poly-Si steps run in quartz tube furnaces and demand the highest quartz purity, since the tunnel oxide is in direct contact with the silicon. FGQuartz supplies the quartz tubes and wafer carriers for both stages.

Silicon heterojunction cells combine amorphous-silicon passivation with crystalline-silicon current collection, achieving efficiencies above 24% in production. The entire process runs below 250°C. HJT PECVD carriers and trays must stay clean at low temperature, where contamination accumulates over time. FGQuartz supplies quartz carrier plates and tray components plus structural parts for the low-temperature wet-cleaning steps.

Multicrystalline and cast-mono silicon cells remain in production at many facilities. DS crucibles are consumed in large quantities — one set per casting cycle regardless of ingot quality. Cast-mono technology uses monocrystalline seeds in the DS furnace to produce predominantly single-crystal ingots at DS economics. FGQuartz supplies DS crucibles in G5 through G8 with consistent dimensional quality across high-volume supply.

Perovskite-silicon tandem cells have demonstrated efficiencies above 33% in research by stacking a wide-bandgap perovskite top cell on a high-efficiency silicon bottom cell. Commercialisation demands the same quartz-glass purity throughout the silicon cell sequence, and introduces new process hardware where quartz serves as deposition-chamber components and substrate carriers. FGQuartz accommodates research-scale prototype quantities.

Multi-junction III-V cells achieve efficiencies above 40% under concentrated illumination and power space satellites and CPV systems. The MOCVD reactors that grow these epitaxial structures need high-purity quartz reaction-chamber components and substrate-holder hardware that survive organometallic chemistry and high-temperature growth. FGQuartz supplies MOCVD-compatible chamber parts and CPV secondary optics.

The relationship between quartz glass quality and solar cell efficiency is direct and measurable. Understanding where contamination enters the silicon, and how it affects performance, is essential for selecting the right quartz component for each process step. For a deeper treatment, read our solar photovoltaic quartz guide.

Transition metals — iron, chromium, nickel, copper and titanium — form deep-level traps in the silicon bandgap with large carrier capture cross-sections. A photo-generated carrier that meets one of these traps recombines as heat instead of photocurrent, lowering minority-carrier lifetime, short-circuit current and open-circuit voltage. Iron is especially damaging because it diffuses rapidly at diffusion temperatures. Iron at parts-per-billion near the wafer surface causes measurable efficiency loss in PERC and TOPCon cells.

CZ silicon contains interstitial oxygen at concentrations set by the crucible dissolution rate, melt convection and pull rate. This oxygen is desirable: during cell processing it precipitates and getters transition metals away from the electrically active surface, improving carrier lifetime. The effect works best within a target oxygen window, so crucible design and inner-surface treatment are the primary variables that control it.

Phosphorus diffusion gettering occurs automatically during emitter diffusion: the heavily doped emitter develops a large segregation coefficient for transition metals and draws iron out of the silicon bulk, after which the emitter is etched away. If the diffusion tube itself adds iron to the wafer surface during this step, it counteracts the very gettering being used to clean the silicon. High-purity quartz diffusion tubes are therefore functionally required — not a quality preference.

Devitrification — crystallisation of amorphous fused silica into cristobalite — is accelerated by alkali metals on wafer surfaces and in process gases. Sodium and potassium from alkaline texturing baths transfer onto wafers and tube walls, catalysing cristobalite formation that appears as white milky deposits, generates particles and weakens the tube. Prevention: strict wafer cleanliness before loading, dedicated tube sets per process step, and visual inspection before each wafer load.

Solar lines process thousands of wafers per hour through each tube, and the boat is the direct interface to the wafer. Slot geometry sets gas access: straight slots give more uniform access to both faces, V-grooves give more positive retention. Slot pitch sets loading density and profile uniformity. Longer boats raise throughput but add bow that must be controlled to prevent wafer contact at the slot walls.

The industry moved from M2 (156 mm) and M6 (166 mm) through M10 (182 mm) to G12 (210 mm) in rapid succession. Each size change requires new boats, tubes and process hardware — a boat for 182 mm M10 will not safely hold 210 mm G12. For lines running multiple sizes during a transition, managing quartz consumable inventory across formats is a real supply-chain challenge. FGQuartz produces tooling for all current formats and transition-format lines.

FGQuartz controls purity at every stage. Purity is verified by ICP-MS analysis on a high-purity fused silica specification. Dimensional parameters — diameter, wall thickness, slot pitch, bow and flatness — are inspected and documented per production run, and inner-surface cleanliness is matched to the contamination sensitivity of each solar process step. Standard items ship in 7–14 days; custom orders in 3–6 weeks.

Tell us your silicon process, furnace platform, wafer format and annual volume. FGQuartz’s engineering team will respond with the right product specification and a competitive quote within 24 hours. Explore related high-temperature quartz or the full application library.