Bis(8-hydroxy-2-methylquinoline)-(4-phenylphenoxy)aluminum, known as BAlq or BAlq3, is widely used as blue-emitting layer materials in organic light-emitting diodes. It is also used as hole-blocking layer or as a “barrier-softening” interfacial layer in between the electron transporting and emissive layers [1, 2, 3, 4].

BAlq is also applied as the host material and electron-transport type hole-blocking layer in red PHOLEDs, and to improve the efficiency and lifetime of PHOLEDs. As a hole-blocking material, it is known to allow for high lifetimes, up to 160,000 hours at a luminance level of 100 cd/m2 [3].

BAlq has a glass transition temperature of 99 °C and is photochemically stable [5].

General Information

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CAS number	146162-54-1
Chemical formula	C32H25AlN2O3
Molecular weight	512.53 g/mol
Absorption	λmax 259 nm (in THF)
Fluorescence	λem 334,477 nm (in THF)
HOMO/LUMO	HOMO = 5.9 eV, LUMO = 2.9 eV
Synonyms	BAlq3 Bis(8-hydroxy-2-methylquinoline)-(4-phenylphenoxy)aluminum Aluminum 4-biphenylolate 2-methyl-8-quinolinolate
Classification / Family	Electron transporting materials, Hole blocking materials, Light emitter layer materials, Phosphorescent host materials, Organic light-emitting diodes, Organic electronics, Sublimed materials

Product Details

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Purity	≥99% (sublimed)
Melting point	Melting point/range: 207 - 214 °C (lit.)
Colour	Light-yellow powder/crystals

*Sublimation is a technique used to obtain ultra pure-grade chemicals. For more details about sublimation, please refer to the Sublimed Materials.

Chemical Structure

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Chemical structure of BAlq, CAS 146162-54-1

Device Structure(s)

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Device structure	ITO (110 nm)/NPB(80 nm)/BtpIr*-doped BAlq (47.5 nm)/Alq3(30 nm)/Li2O(0.5nm)/Al(100nm) [5]
Colour	Red
Max. EQE	8.6%
Max. Luminance	179 cd/m2

Device structure	ITO/CuPc (15 nm)/NPB (80 nm)/NPB: 0.5 wt% DCJTB (20 nm) /Alq3:0.5 wt% C545T (3 nm)/MADN:0.8 wt% DSA-ph*(40 nm)/BAlq3 (10 nm)/LiF/Al [6]
Colour	White
Max. Luminance	45,000 cd/m2
Max. Current Efficiency	20.8 cd/A
Max. Power Efficiency	15.9 lm W−1

Device structure	ITO/MoOx (5 nm)/NPB (40 nm)/4% Y-Pt*:TCTA (20 nm)/8% FIrpic:mCP(10 nm)/8% FIrpic:UGH2 (10 nm)/BAlq (40 nm)/LiF (0.5 nm)/Al (100 nm) [7]
Colour	White
Max. EQE	16.0%
Max. Current Efficiency	45.6 cd/A
Max. Power Efficiency	35.8 lm W−1

*For chemical structure informations please refer to the cited references

Characterisation (TGA and DSC)

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TGA and DSC trace of Bis(8-hydroxy-2-methylquinoline)-(4-phenylphenoxy)aluminum (BAlq).