ELECTRON-HOLE PLASMA AND ELECTRON-HOLE LIQUID IN LAYERED INDIUM SELENIDE

Photoluminescence spectra of layered indium selenide have been studied over a wide temperature range from 4. 2 to 100 K and a wide interval of optical excitation density (N//e//x). It is demonstrated that the longwave edge of the K-line undergoes a violent shift with increasing temperature, which confirms the conclusion that the K-line (hv//m//a//x equals 1. 32 ev) is due to radiative recombination of the e-h pairs in electron-hole liquid (EHL). At pulse excitation (N//e//x approx. 10**2**2 phot/sm**2 multiplied by (times) sec) a broad band is observed at the place of excitonic emission lines. The form of this band is described satisfactorily by recombination of the electron-hole plasma. The e-h plasma temperature on the excitation level is estimated. The character of electric field influence upon radiative recombination spectra allows to discuss the mechanism of EHL origin in InSe.