{'fraction_non_alphanumeric': 0.028698979591836735, 'fraction_numerical': 0.007653061224489796, 'mean_word_length': 5.483471074380165, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Molten Salt Assisted Annealing for Making Colloidal ZnGa2O4:Cr Nanocrystals with High Persistent Luminescence.

Persistent luminescent nanocrystals (PLNCs) in sub-10 nm domain are considered most fascinating inventions in lighting technology owing to their excellent performance in anti-counterfeiting, luminous paints, bioimaging, security applications, etc. Further improvement of persistent luminescence (PersL) intensity and lifetime is needed to achieve the desired success while keeping uniform sub-10 nm size of PLNCs. In this work, we have introduced the concept of molten salt confinement to thermally anneal as-synthesized ZnGa 2 O 4 :Cr 3+ (ZGOC) colloidal NCs (CNCs) in a molten salt media at 650 o C for the first time. This method led to significantly monodispersed and few agglomerated NCs with much improved photoluminescence (PL) and PersL intensity without much size growth of the pristine CNCs. Other strategies, such as: (i) thermal annealing, (ii) overcoating, and (iii) core-shell strategy, have also been tried to improve PL and PersL but we could not achieve improvement in their PL and PersL simultaneously. Moreover, directly annealing of the CNCs in air without the molten salt assistance could significantly improve both PL and PersL but lead to particle heterogeneity and aggregation, which are highly unsuitable for in vivo imaging. We believe this work provides a novel strategy to design PLNCs with high PL intensity and long PersL duration without losing their nanostructural characteristics, water dispersibility and biocompatibility.