Double-Heterojunction Crystalline Silicon Solar Cell with Electron-Selective TiO 2 Cathode Contact Fabricated at 100ºC with Open-Circuit Voltage of 640 mV Janam Jhaveri,1,2, Ken A. Nagamatsu1,2, Alexander H. Berg1,2, Gabriel Man1,2, Girija Sahasrabudhe1,3, Sigurd Wagner1,2, Jeffrey Schwartz1,3, Antoine Kahn1,2, and James C. Sturm1,2 1Princeton Institute for the Science and Technology of