Probing the structure, morphology and multifold blue absorption of a new red-emitting nanophosphor for LEDs

Savvi Mishra; Isha Bharti; N. Vijayan; R. K. Sharma; L. M. Kandpal; V. Shanker; M. K. Dalai; R. Rajeswari; C. K. Jayasankar; S. Surendra Babu; D. Haranath

arXiv · 1208.3135

Probing the structure, morphology and multifold blue absorption of a new red-emitting nanophosphor for LEDs

Savvi Mishra·Isha Bharti·N. Vijayan·R. K. Sharma·L. M. Kandpal·V. Shanker·M. K. Dalai·R. Rajeswari·C. K. Jayasankar·S. Surendra Babu·D. Haranath

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Abstract

There has been a stringent demand for blue (~450-470 nm) absorbing and red (~611 nm) emitting material system in phosphor converted white light emitting diodes (WLEDs) available in the market. Conventionally used red-emitting Y2O3:Eu3+phosphor has negligible absorption for blue light produced by GaInN based LED chip. To address this issue, a new red-emitting Gd2CaZnO5:Eu3+ (GCZO:Eu3+) nanophosphor system having exceptionally strong absorption for blue (~465 nm) and significant red (~611 nm) photoluminescence (PL) is presented. This is attributed to a dominant f-f transition (5D0\rightarrow7F2) of Eu3+ ions, aroused due to an efficient energy transfer from the Gd3+ sites of the host lattice to Eu3+ ions. X-ray diffraction and microscopy observations revealed the nanocrystalline nature and a bit elongated morphology of the sample respectively. While the energy dispersive x-ray analysis identified the chemical constituents of the GCZO:Eu3+ nanophosphor, the color overlay imaging confirmed the substitution of Eu3+ for Gd3+ ions. It is highly anticipated that the multifold absorption at ~465 nm would certainly improve the color rendering properties of existing WLEDs.

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Savvi Mishra, Isha Bharti, N. Vijayan, R. K. Sharma, L. M. Kandpal, V. Shanker, M. K. Dalai, R. Rajeswari, C. K. Jayasankar, S. Surendra Babu, D. Haranath. 2012-08-15. Probing the structure, morphology and multifold blue absorption of a new red-emitting nanophosphor for LEDs. https://arxiv.org/abs/1208.3135

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