Weakening thermal quenching to enhance luminescence of Er³⁺ doped β‐NaYF₄ nanocrystals via acid‐treatment

Abstract

Rare earth (RE) ions‐doped luminescent nanocrystals (NCs) with numerous unique advantages have attracted tremendous interest for the wide applications from science to engineering, yet suffering from the shortcoming of thermal quenching coming from surface organic ligands. We propose utilizing a facile acid‐base reaction to remove surface organic ligands introduced choosing carboxylic acids as stabilizing agent and weaken thermal quenching. The results showed that the acid‐base reaction displayed an outstanding cleaning effect. After acid‐treatment, most surface organic ligands were removed, and there was no influence on crystal structure and morphology of as‐prepared β‐NaYF4:Er3+ NCs. Meanwhile, with no surface organic ligands capping, β‐NaYF4:Er3+ NCs preferred brighter emission after thermal treatment, including up‐conversion (UC), near‐infrared (NIR), and mid‐infrared (MIR) emission. When calcined the acid‐treated β‐NaYF4:Er3+ NCs in different atmosphere, such as oxygen and reducing atmosphere (15%H2 + 85%N2), an unexpected enhancement of all emission bands in Er3+ was determined under phase transformation temperature, especially in oxygen atmosphere. Furthermore, all the fluorescence lifetimes of Er3+ also exhibited obvious extension. Our results supposed that the β‐NaYF4:Er3+ NCs have promising applications in safety ink, and the acid‐treatment by diluted hydrochloric acid is a general approach to remove deleterious organic ligands on NC surface further to weaken thermal quenching.

Synthesis and design of NaYF4 microprisms via a microwave‐assisted approach for highly sensitive optical thermometry applications

“…[1][2][3][4][5][6] Yang et al have reported a facile approach to weaken the thermal quenching procedure for improving upconversion efficiency of Er 3+ -doped β-NaYF 4 nanocrystals via acidtreatment. 10 More exertions should be dedicated to find novel procedures to improve the upconversion performance of the fluorides.…”

“…Several research works have been reported on the altering of crystal field using the variation in electric/ magnetic field, doping with a transition metal, and rare‐earth elements to enhance upconversion emission 1‐6 . Yang et al have reported a facile approach to weaken the thermal quenching procedure for improving upconversion efficiency of Er 3+ ‐doped β‐NaYF 4 nanocrystals via acid‐treatment 10 . More exertions should be dedicated to find novel procedures to improve the upconversion performance of the fluorides.…”

Structural role of Nd2O3 as a dopant material in modified borate glasses and glass ceramics

“…A family of rare earth (RE) elements is considered between the elements of the lanthanide group which shows pronounced biological activity as they are capable of replacing Ca 2+ in investigated glass matrix [1][2]. Most of the recent studies have concentrated on enhancing the bioactivity of glass materials by the effect of RE ions [3][4][5][6][7][8]. These advances include the preparation of special glass materials, or the introduction of certain useful elements in the matrix of the simple glass materials [9].…”

“…The research interest in the branch of borate glass systems is due to their anomalous behavior. Borate glass has been studied most recently in contrast with other traditional glasses due to its good optical and mechanical properties [8,10]. Borate glass systems are well known to have a stable structure against ambient humidity, good corrosion resistance in mechanical strength and chemical toughness.…”

“…Borate oxide glasses are one of the most suitable for doping with RE 3+ ions among the potential host glasses. [8][9][10][11][12][13][14].…”