Original experimental data on the recombination radiation of free excitons, the band-A of luminescence, and the recombination radiation of electron-hole liquid in a diamond have been presented. A review of the literature on the recombination radiation in diamond and its application was performed. There was no displacement of free-exciton band at 5.275 eV in the temperature range of 80–300 K. At low excitation levels, the temperature dependence of free-exciton band intensity had the maximum at ∼150 K. The band-A of luminescence, due to defects containing sp2-hybridizedcarbon bonds, is located in the spectral range 350–650 nm with a maximum at ∼440 nm and is characterized by the decay time of 8–19 m sec in the temperature range of 80–300 K. The electron-hole liquid recombination radiation in the diamond was observed at temperatures of <200 K and at peak densities of charge carriers of ≥(0.3–1.0)×1018 cm-3. Condensation of electron-hole liquid implies the displacement of the free-exciton intensity maximum on the temperature dependence to higher temperatures. The critical temperature of electron-hole liquid condensation takes values in the range of 160–220 K. The literature data on the diamond light-emitting devices are discussed.
Part of the book: Luminescence