High sensitivity fluorescence up-conversion spectroscopy of 3MLCT emission of metal-organic complexes Li Liu, Damianos Agathangelou, Thomas Roland, Olivier Crégut, Thibaud Duchanois, Marc Beley, Jérémie Léonard, Philippe Gros and Stefan Haacke EPJ Web Conf., 205 (2019) 09009 Published online: 16 April 2019 DOI: 10.1051/epjconf/201920509009