An ideal method to quantify the internal quantum efficiency (IQE) of radiation for condensed-matter placed outside an integrating sphere (φ-configuration) is demonstrated by showing the data for a freestanding GaN crystal using improved omnidirectional photoluminescence (ODPL) spectroscopy, Kojima et al. [J. Appl. Phys. 120, 015704 (2016)]. The crystal is optically coupled with the sphere through a pinhole fabricated on the sphere, and thus ODPL with φ-configuration gives IQE because the light-escaping cone for the crystal defines the observable photoluminescence owing to the large absorption and crystal thickness. This nondestructive ODPL configuration is applicable to large size crystals or semiconductor wafers.
ASJC Scopus subject areas
- Physics and Astronomy(all)