Temperature dependent direct-bandgap light emission and optical gain of Ge
Liu Zhi, He Chao, Zhang Dongliang, Li Chuanbo, Xue Chunlai, Zuo Yuhua, Cheng Buwen
       

Optical gain spectra of 0.25% tensile strained Ge films on Si with 6 × 1019 cm−3 n-doping at various temperatures. The input carrier concentration n = p = 1 × 1019 cm−3.