Gen Li,Yaqi Wang,Min Tao,Siqi Chen,Bozhi Zhou,Quan Li,Xin Li,Heming Deng,Hao Huang,Haoshuang Gu,Yuebin Li
Developing efficient strategies to fabricate planar photoluminescence scintillators is of great importance to explore X-ray detectors with new platform. Rare-earth (RE) doped Lu 2 O 3 thin films are successfully fabricated by mild aqueous phase electrochemical deposition on ITO/glass substrates with low-temperature post-annealing treatment. The as-prepared Lu 2 O 3 :RE 3+ (RE = Eu, Tb and Tm) thin films exhibit steerable thickness, high transparency in the visible-NIR range, and low transmittance at UV band mainly due to the oxygen-metal (O 2- -RE 3+ ) charge transfer processes and the 4f-4f transitions of the RE 3+ . The Lu 2 O 3 :RE 3+ thin films emit intense red, green and blue (RGB) photoluminescence, which mainly correspond to the 5 D 0 - 7 F 2 transition of Eu 3+ , 5 D 4 - 7 F 5 transition of Tb 3+ and 1 G 4 - 3 H 6 transition of Tm 3+ respectively. Moreover, the transparent Lu 2 O 3 :RE 3+ thin films also exhibit high sensitivity and linearity luminescence to the X-ray stimulation in a dose rate from 30 to 160 mGy s −1 . This rapid and energy-saving synthesis show high efficiency to fabricate rare-earth doped thin-film with a tunable optical performance for optoelectrical application in the fields of solar light concentrators, agricultural light conversion thin films, biosensors , photodetectors and especially the X-ray detectors.
Liu Yang,Han Fei,Li Fushan,Zhao Yan,Chen Maosheng,Xu Zhongwei,Zheng Xin,Hu Hailong,Yao Jianmin,Guo Tailiang,Lin Wanzhen,Zheng Yuanhui,You Baogui,Liu Pai,Li Yang,Qian Lei
An ideal anti-counterfeiting technique has to be inexpensive, mass-producible, nondestructive, unclonable and convenient for authentication. Although many anti-counterfeiting technologies have been developed, very few of them fulfill all the above requirements. Here we report a non-destructive, inkjet-printable, artificial intelligence (AI)-decodable and unclonable security label. The stochastic pinning points at the three-phase contact line of the ink droplets is crucial for the successful inkjet printing of the unclonable security labels. Upon the solvent evaporation, the three-phase contact lines are pinned around the pinning points, where the quantum dots in the ink droplets deposited on, forming physically unclonable flower-like patterns. By utilizing the RGB emission quantum dots, full-color fluorescence security labels can be produced. A convenient and reliable AI-based authentication strategy is developed, allowing for the fast authentication of the covert, unclonable flower-like dot patterns with different sharpness, brightness, rotations, amplifications and the mixture of these parameters.