Temperature dependent photoluminescence of Cr3+ doped Sr8MgLa(PO4)7

Cr3+‐Doped Sc‐Based Fluoride Enabling Highly Efficient Near Infrared Luminescence: A Case Study of K2NaScF6:Cr3+

“…It is found that the temperature‐dependent FWHM of the K 2 NaScF 6 :0.10Cr 3+ fits well with Equation (Figure 3g), and the S and hυ are calculated as 2.96 and 44.52 meV, respectively. The Huang–Rhys S (2.96) value is obviously lesser than that of the YAl 3 (BO 3 ) 4 :1%Cr 3+ (5.93), [ 10 ] GdAl 3 (BO 3 ) 4 :1%Cr 3+ (5.37), [ 10 ] Sr 8 MgLa(PO 4 ) 7 :1%Cr 3+ (7.9), [ 11 ] La 3 Sc 2 Ga 3 O 12 :Cr 3+ (6), [ 33 ] Cs 2 NaAlF 6 :Cr 3+ (4.5), [ 34 ] and LiNbO 3 :Cr 3+ (6.86). [ 34 ] It is well known that a stronger electron coupling strength would result in a broader width of Cr 3+ emission, whereas it usually causes more serious thermal quenching effect as well.…”

“…Though the AlGaAs NIR light‐emitting diodes (LEDs) possess the advantages of small size, high efficiency, and long lifetime, their full width at half maximum (FWHM < 50 nm) is too narrow. [ 9–12 ] In this regard, the combination of blue InGaN chip and broadband NIR emitting phosphor will be an ideal approach to construct portable and smart NIR light source for its compact size and high efficiency as well as the low cost. [ 12 ] However, as the energy difference between the emissions of blue InGaN chip and NIR emitting phosphor is larger than that between the blue chip and yellow or red emitting phosphor, more heat will be inevitably produced in the NIR phosphor‐converted (pc) LEDs.…”

Broadband near-infrared (NIR) emission realized by the crystal-field engineering of Y3−xCaxAl5−xSixO12:Cr3+(x= 0–2.0) garnet phosphors

“…Two other weak bands are located at 244 and 280 nm, which correspond to the O 2À -Cr 3+ charge transfer (CT) and 4 A 2 (4F) -4 T 2 (4F) transition, respectively. 22 The emission spectrum assigned to the 4 T 2 -4 A 2 transition is dominated by a broadband covering the spectral range of 600 to 1100 nm (centred at 744 nm). In addition, a narrow peak (i.e., R-line) at 689 nm, due to the 2 E -4 A 2 transition, is also observed.…”

“…18 Several kinds of broadband phosphors with weak crystal fields have been reported recently, such as SrSc 2 O 4 :Cr, 19 Ca 2 MgWO 6 :Cr, 20 ScBO 3 :Cr, 21 and Sr 8 MgLa(PO 4 ) 7 :Cr. 22 In addition, broadband emissions can be achieved by decreasing the crystal field strength of a strong crystal field material by a substitution strategy. A notable example is garnet, which has a structure form of A 3 B 2 C 3 O 12 .…”

The hydrothermally synthesis of K3AlF6:Cr3+ NIR phosphor and its performance optimization based on phase control

“…[15][16][17][18] One strategy is to employ transition-mental ions, Cr 3+ for instance. [19][20][21] The main hosts for Cr 3+ -doped NIR phosphor are germanate, [22][23][24][25][26][27] silicate, [28][29][30][31][32] phosphate, [33][34][35] and borate. [36][37][38][39] The synthesis of these phosphors requires calcination at a temperature of 800-1600°C, which results in high production costs.…”