Creation of degenerate electron-hole pairs by exciton Mott transition in CuCl

Summary form only given.In direct-gap semiconductors, low temperature states of high-density electrons and holes show collective quantum mechanical effects such as the formation of electron-hole liquid and exciton condensation. In the usual band-to-band excitation, the temperature of the carriers remains high within their lifetime. However, if we create electron-hole pairs through the Mott transition of excitons, we can reduce the initial temperature. In this report, we show the results of femtosecond time-resolved emission spectra of electron-hole pairs created by the exciton resonance excitation in CuCl.