Dixit Prashant, Pandey Prashant Kumar, Chauhan Vaibhav, Deshmukh Pratik, Satapathy S, Pandey Praveen C
Department of Physics, Indian Institute of Technology (Banaras Hindu University), Varanasi-221005, (U.P.) India.
Functional Bio-Materials Lab., Laser Biomedical Applications Division, Raja Ramanna Centre for Advanced Technology, Indore, 452013, India.
Methods Appl Fluoresc. 2022 Aug 5;10(4). doi: 10.1088/2050-6120/ac8528.
The research in developing a single ingredient phosphor for white-light emission is progressively increasing. It is well known that theF → H(yellow) andF → H(blue) transitions of Dyions give near-white light emission. The white light emission of Dyions can be enhanced via improving the crystallinity of the host phosphor via co-doping of transition metal ions. In this paper, we report a significant improvement in the white light emission of Dydoped CaMoOby co-doping Znions. The x-ray diffraction pattern confirms the tetragonal phase of pure and doped CaMoOphosphor. The peak broadening and a red-shift in the absorption peak are observed by UV-vis absorption analysis of Zn/Dydoped CaMoO. From Photoluminescence studies, we have observed that in Dydoped CaMoO, the 4% Dydoped CaMoOexhibits maximum emission. The Znions are co-doped to further increase the luminescence intensity of CaMoO:4%Dyand the maximum luminescence is obtained for 0.25% Znconcentration. Two intense emission peaks centered at 484 nm and 574 nm related to transitionsF → HandF → Hof Dyion are observed for Dydoped phosphor. TheF → Htransition is the forced electric dipole transition which is affected by its chemical environment. After Znco-doping, theF → Htransition is affected due to a change in asymmetricity around the Dyions. The 0.25% co-doping of Zngives 34% enhancement in luminescence emission of 4% Dydoped CaMoO. As a result, the CIE coordinates of chromaticity diagram and the color purity of the 0.25% Znco-doped CaMoO:4Dyshow improvement in the overall white light emission. We have shown that with Znco-doping, the non-radiative relaxations are reduced which results in improved white light emission of Dyions.
开发用于白光发射的单一成分磷光体的研究正在逐渐增加。众所周知，Dy离子的F→H（黄色）和F→H（蓝色）跃迁可产生近白光发射。通过过渡金属离子的共掺杂提高主体磷光体的结晶度，可以增强Dy离子的白光发射。在本文中，我们报道了通过共掺杂Zn离子，Dy掺杂的CaMoO的白光发射有显著改善。X射线衍射图谱证实了纯CaMoO磷光体和掺杂CaMoO磷光体的四方相。通过对Zn/Dy掺杂的CaMoO进行紫外-可见吸收分析，观察到吸收峰的峰展宽和红移。通过光致发光研究，我们观察到在Dy掺杂的CaMoO中，4% Dy掺杂的CaMoO表现出最大发射。共掺杂Zn离子以进一步提高CaMoO:4%Dy的发光强度，在Zn浓度为0.25%时获得最大发光。对于Dy掺杂的磷光体，观察到两个以484 nm和574 nm为中心的强发射峰，与Dy离子的F→H和F→H跃迁有关。F→H跃迁是受其化学环境影响的强制电偶极跃迁。Zn共掺杂后，由于Dy离子周围不对称性的变化，F→H跃迁受到影响。0.25%的Zn共掺杂使4% Dy掺杂的CaMoO的发光发射增强了34%。结果，色度图的CIE坐标和0.25% Zn共掺杂的CaMoO:4Dy的色纯度显示出整体白光发射有所改善。我们已经表明，通过Zn共掺杂，非辐射弛豫减少，这导致Dy离子的白光发射得到改善。
