Gain roll-off in cadmium selenide colloidal quantum wells under intense optical excitation.

ABSTRACT: Colloidal quantum wells, or nanoplatelets, show among the lowest thresholds for amplified spontaneous emission and lasing among solution-cast materials and among the highest modal gains of any known materials. Using solution measurements of colloidal quantum wells, this work shows that under photoexcitation, optical gain increases with pump fluence before rolling off due to broad photoinduced absorption at energies lower than the band gap. Despite the common occurrence of gain induced by an electron-hole plasma found in bulk materials and epitaxial quantum wells, under no measurement conditions was the excitonic absorption of the colloidal quantum wells extinguished and gain arising from a plasma observed. Instead, like gain, excitonic absorption reaches a minimum intensity near a photoind

SUBMITTER: Diroll BT 

PROVIDER: S-EPMC9110332 | biostudies-literature | 2022 May

REPOSITORIES: biostudies-literature