Rare Vintage 1970s Monsanto Silicon Solar Cell Wafer – Lot 77 (Matrix Grid Pattern)Includes High-Resolution Print Copy of Original 1977 Monsanto Factory Traveler Paperwork!
An incredible piece of early American semiconductor and photovoltaic history. This listing is for ONE (1) authentic vintage Monsanto 3.5-inch silicon solar cell wafer from production Lot 77, manufactured in September 1977.
Item Features & Specs:• Manufacturer: Monsanto Industrial Chemicals Co. / Semiconductor Division• Diameter: ~3.5 Inches (3.425" - 3.622")• Wafer Design: Full matrix / cross-hatched grid contact layout on front face.• Rear Stamping: Authentically back-stamped in black ink "H - 9 77" (September 1977).• Dopant / Type: N-Type, Phosphorus Doped (PHOS).• Provenance Included: Every order includes a high-resolution paper print copy of the original 1977 Monsanto factory traveler card detailing process steps (Diffusion, Etch, Grid Screen, Solder Dip, Test).
Condition:Wafers are clean, intact, and uncracked with excellent silver grid contact alignment. Minor authentic factory handling marks on back faces. Please review high-res images for visual details.
Shipping & Packaging:Silicon wafers are thin and brittle. Each wafer is meticulously sandwiched between thick rigid cardboard sheets and shipped inside a cushioned rigid box via USPS Ground Advantage with full tracking.
*Take advantage of multi-item discounts when purchasing 2 or more!*