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
       

Light emission intensitits of various tensile strained Ge at different temperatures. The input carrier concentration n = p = 1 × 1019 cm−3.