title: Freestanding carbon nanodots/poly (vinyl alcohol) films with high photoluminescent quantum yield realized by inverted-pyramid structure.
abstract: Carbon nanodots (C-dots) have attracted great attention for their biocompatibility and strong tunable photoluminescence (PL). However, aggregation-induced PL quenching blocks their practical application in solid-state optoelectronics. Here, we report a luminescent C-dots freestanding film with a substantially enhanced high quantum yield (QY) of 72.3%. A facile template method, rather than complicate lithography and etching technique is proposed to fabricate the C-dots composite films with large-area (8 inch × 8 inch) ordered micro-scale inverted-pyramid patterns on the surface. The control experiment and theoretical analysis demonstrate the key success to QY enhancement lies in the separation of C-dots and the pattern of surface inverted-pyramid structure. This work realizes the QY enhancement simply by geometrical optics, not the chemical treatment of luminescent particles. It provides a general approach to fabricate large-area freestanding luminescent composite film with high QY.
authors.affiliation: Laboratory of Condensed Matter Spectroscopy and Opto-Electronic Physics, and Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China.
authors.forename: Linna
authors.initials: L
authors.lastname: Pang
authors.forename: Lixiang
authors.initials: L
authors.lastname: Ba
authors.forename: Wei
authors.initials: W
authors.lastname: Pan
authors.forename: Wenzhong
authors.initials: W
authors.lastname: Shen