Free-exciton emissions increase non-linearly by cathodoluminescence (CL) above the threshold probe current of 30 μA in high-pressure high-temperature synthetic type-IIa diamond. A droplet of electron-hole liquid (EHL) is also observed by CL for the first time. Furthermore, boron acceptor bound-exciton emission as well as free-exciton emission also increases super-linearly in an unintentionally boron-contaminated area. The threshold probe current of non-linear increase of excitonic emission is in accordance with the emergence of the EHL peak. It is considered that the non-linear increase of excitonic emissions is due to the increase in the radiative recombination rate of free excitons under high exciton density.
ASJC Scopus subject areas
- 化学 (全般)