CREATE TABLE table_4263 ("Material" TEXT, "Type" TEXT, "Geometry" TEXT, "Output voltage" TEXT, "Output power" TEXT, "Synthesis" TEXT, "Researched at" TEXT)

Where was d: ~50nm, l: ~600nm geometry researched?
SELECT "Researched at" FROM table_4263 WHERE "Geometry" = 'D: ~50nm, L: ~600nm'
SELECT "Researched at" FROM "table_4263" WHERE "Geometry" = 'D: ~50nm, L: ~600nm'