user: Question: Where was D: ~50nm, L: ~600nm geometry researched?
Columns: ['Material', 'Type', 'Geometry', 'Output voltage', 'Output power', 'Synthesis', 'Researched at']
Types: ['text', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['ZnO (n-type)', 'Wurtzite', 'D: ~100nm, L: 200~500nm', 'V P =~9 mV @ R=500MΩ', '~0.5 pW per cycle (estimated)', 'CVD, hydrothermal process', 'Georgia Tech.']
SQL:

assistant: SELECT "Researched at" FROM "Table" WHERE "Geometry" = 'D: ~50nm, L: ~600nm';