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 intensities of various n-doped Ge at different temperatures. The input carrier concentration n = p = 1 × 1019 cm−3.