Resonant light emission from N-doped germanium-on-insulator microdisks at room-temperature

Tensile-strained, n-doped germanium-on-insulator (GOI) substrates with doping concentration up to 1.0×10²⁰ cm^-3 are fabricated by wafer bonding and spin-on-dopant. Resonant photoluminescence peaks corresponding to whispering gallery modes are obtained from microdisks fabricated on GOI at room-temperature.