A multiphase strategy for realizing green cathodoluminescence in 12CaO·7Al2O3–CaCeAl3O7:Ce3+,Tb3+ conductive phosphor

Abstract

A multiphase strategy is proposed and successfully applied to make the insulating green phosphor CaCeAl 3 O 7 :Tb 3+ conductive in the form of 12CaO·7Al 2 O 3 -CaCeAl 3 O 7 :Ce 3+ ,Tb 3+ . The phosphor shows bright green-light emission with a short lifetime (2.51 ms) under low-voltage electron beam excitation (3 kV). The green photo-and cathodoluminescence from 5 D 4 -7 F J ( J = 6, 5, 4, 3) transitions of Tb 3+ are significantly enhanced in comparison with pure C12A7:Tb 3+ . It was confirmed that this enhancement is the consequence of the joint effects of energy transfer from Ce 3+ to Tb 3+ and broadening of the absorption spectrum of Ce 3+ due to the existence of multiple phases. In particular, under 800 V electron beam excitation, cathodoluminescence is improved by the modified electrical conductivity of the phosphor.When compared to the commercial Zn 2 SiO 4 :Mn 2+ with a long luminescence lifetime of 11.9 ms, this conductive green phosphor has greater advantage for fast displays.

Characteristics, Thermodynamics, and Preparation of Nanocaged 12CaO·7Al2O3 and Its Derivatives

“…found C12A7–Eu 2+ /Nd 3+ showed indigo long after‐glow with phosphorescence intensity increasing with doping content of Nd 3+ (0.05, 0.10 and 0.20 mol.%). Liu et al . found phosphor of C12A7–Tb 3+ /Ce 3+ (with additional phase of CaCeAl 3 O 7 ) with green light emission of short lifetime (2.51 ms) under low‐voltage electron beam excitation (3 kV).…”

“…For C12A7-Er 3+ and C12A7-Yb 3+ /Er 3+ , two main emission bands centered around 530/550 nm [green, up-conversion emission intensity increasing with doping content of Er 3+ (1.0, 1.5, 3.0 mol.%)] and 660 nm [red, with intensity ratio of red-to-green up-conversion emission increasing with doping content of Yb 3+ (1.0, 2.0, 10.0 mol.%)/Er 3+ (fixed at 1.0 mol.%)] were observed via up-conversion process by Wang et al 22 Zhang et al 77 found C12A7-Eu 2+ /Nd 3+ showed indigo long after-glow with phosphorescence intensity increasing with doping content of Nd 3+ (0.05, 0.10 and 0.20 mol.%). Liu et al 25 found phosphor of C12A7-Tb 3+ /Ce 3+ (with additional phase of CaCeAl 3 O 7 ) with green light emission of short lifetime (2.51 ms) under low-voltage electron beam excitation (3 kV). Liu et al 27 found optical performances of C12A7-Re derivatives were affected by the sort and amount of encaged anions via optical and EPR spectroscopy analysis.…”

“…For instance, C12A7 sintered in different atmospheres (including H 2 , H 2 /N 2 , O 2 , and vacuum) could lead to various derivatives with special performances (see the part of “Derivatives of C12A7”) . With arising interest in C12A7‐related materials, new investigations regarding to its derivatives have been reported recently . In order to further evaluate C12A7 and its family, it is therefore the objectives of this article to summarize the structure of C12A7, review its thermodynamic data (Δ H of C12A7 will be optimized and discussed), and outline the characteristics and preparation of its derivatives of C12A7:M n− (for substitution of free O 2− ion) and C12A7–M n− (for doping).…”

“…Many works have then been devoted to further characterize C12A7 and its derivatives for practical applications with significant achievements, 8,[11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] including, for example, photo-induced electrical conduction 8 and luminescence properties. 26 Despite the fact that some characteristics of C12A7 being reviewed recently by Kim et al 28,29 with focus on fabrication and properties of fantastic C12A7-e À electride, plus a few derivatives, and partial phase diagram of relevance, it is far away from completion to provide a whole picture of material database.…”

“…9,[53][54][55][56] With arising interest in C12A7-related materials, new investigations regarding to its derivatives have been reported recently. 17,20,25,[57][58][59] In order to further evaluate C12A7 and its family, it is therefore the objectives of this article to summarize the structure of C12A7, review its thermodynamic data (DH of C12A7 will be optimized and discussed), and outline the characteristics and preparation of its derivatives of C12A7:M nÀ (for substitution of free O 2À ion) and C12A7-M nÀ (for doping). Crystal lattice of C12A7 [3][4][5]7,10,60,61 belongs to cubic with space group of I-43d and lattice constant of 1.199 nm 3 (Fig.…”