Seeing the invisible plasma with transient phonons in cuprous oxide. Issue 2 (12th December 2016)

• Record Type: Journal Article
• Authors: Frazer, Laszlo; Schaller, Richard D.; Chang, Kelvin B.; Chernatynskiy, Aleksandr; Poeppelmeier, Kenneth R.
• Is Part Of: Physical chemistry chemical physics. Volume 19:Issue 2(2017)
• Page Start: 1151
• Page End: 1157
• Publication Date: 2016-12-12
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.3
• DOI: 10.1039/c6cp06532e
• Languages: English
• ISSNs: 1463-9076

Abstract

Abstract : Light conversion leaks energy by transmitting sub-bandgap light and by plasma phonon emission. Here, phonons are upconverted to excitons using sub-bandgap light, capturing the phonon dynamics. Abstract : The emission of phonons from electron–hole plasma is the primary limit on the efficiency of photovoltaic devices operating above the bandgap. In cuprous oxide (Cu2 O) there is no luminescence from electron–hole plasma. Therefore, we searched for optical phonons emitted by energetic charge carriers using phonon-to-exciton upconversion transitions. We found 14 meV phonons with a lifetime of 0.916 ± 0.008 ps and 79 meV phonons that are longer lived and overrepresented. It is surprising that the higher energy phonon has a longer lifetime.