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Product Code M361-1g
Price £180 ex. VAT

NPB, chemical with outstanding hole transport capability

Enhances device morphology and is beneficial for device longevity

Overview | Specifications | Pricing and Options | MSDS | Literature and Reviews

N,N′-Di(1-naphthyl)-N,N′-diphenyl-(1,1′-biphenyl)-4,4′-diamine, also known as NPB or NPD, has been used intensively in OLEDs and other organic electronic devices such as polymer photovoltaics (OPV) and perovskite solar cells for its outstanding hole transport capability.

NPB (NPD) from Ossila was used in the high-impact paper (IF 7.059)

NPB (NPD) from Ossila was used in the high-impact paper (IF 7.059), Synergistic effects of charge transport engineering and passivation enabling efficient inverted perovskite quantum-dot light-emitting diodes, J. Pan et al., J. Mater. Chem. C, 8, 5572-5579 (2020); DOI: 10.1039/D0TC00661K.

NPB is considered as one of the best materials within its competition, and has become the most common-used material in OLEDs' application. This is due to its increased Tg up to 95 °C, which enhances device morphology and is beneficial for device longevity [1].

General Information

CAS number 123847-85-8
Chemical formula C44H32N2
Molecular weight 588.74 g/mol
HOMO/LUMO HOMO = 5.5 eV, LUMO = 2.4 eV
Absorption* λmax 339 nm
Fluorescence λem 450 nm (in THF)
  • NPB, NPD
  • N,N′-Di(1-naphthyl)-N,N′-diphenyl-(1,1′-biphenyl)-4,4′-diamine
  • N,N′-Bis(naphthalen-1-yl)-N,N′-bis(phenyl)benzidine
Classification / Family Triphenylamines, Naphtalene, Hole-transport layer materials, Electron block layer materials, Hole-injection layer materials, Organic light-emitting diodes (OLEDs), OFETs, Organic Photovoltaics, Polymer solar cells, Perovskite solar cells

* Measurable with an optical spectrometer, see our spectrometer application notes.

Product Details


> 99.5% (sublimed)

> 98.0% (unsublimed)
Melting point 279-283 °C (lit.)
Appearance Off-White powder

* Sublimation is a technique used to obtain ultra pure-grade chemicals, see sublimed materials.

Chemical Structure

NPB NPD chemical structure
Chemical structure of N,N′-Di(1-naphthyl)-N,N′-diphenyl-(1,1′-biphenyl)-4,4′-diamine (NPB)

Device Structure(s)

Device structure

ITO/NPB (30 nm)/NPB: DCJTB: C545T* (10 nm)/NPB (4 nm)/DNA (8 nm)/(BCP) (9 nm)/Alq3 (30 nm)/LiF (1 nm)/Al (100 nm) [2]
Colour White white light emitting device
Max. Luminance 13,600 cd/m2
Max. Current Efficiency 12.3 cd/A
Max. Power Efficiency 4.4 lm W1

Device structure

ITO/MoO3 (7nm)/NPB (85 nm)/ (PPQ)2Ir(acac):Ir(ppy)3:FIrpic:mCP/TAZ/LiF/Al [3]
Colour White white light emitting device
Max. EQE 20.1%
Max. Power Efficiency 41.3 lm W1
Device structure ITO/PEDOT:PSS/NPB/mCP/FPt*(1.5 nm)/OXD-7/CsF/Al [4]
Colour White white light emitting device
Max. EQE 17.5%
Max. Power Efficiency 45 lm W1
Device structure ITO/2-TNATA:33% WO3 (100 nm)/NPB (10 nm)/Alq3 (30 nm)/Bphen (20 nm)/BPhen: 2% Cs (10 nm)/Al (150 nm) [5]
Colour Green green light emitting device
Operating Voltage for 100 cd/m2 3.1 V
Current Efficiency for 20 mA/cm2 4.4 cd/A
Power Efficiency for 20 mA/cm2 3.3 lm W1
Device structure ITO/2-TNATA (60 nm)/NPB (15 nm)/TAT* (30 nm)/ Alq3 (30 nm)/LiF (1 nm)/Al (200 nm) [6]
Colour Deep Blue deep blue light emitting device
EQE at 10 mA/cm2 7.18
Current Efficiency at 10 mA/cm2 3.64 cd/A
Power Efficiency at 10 mA/cm2 1.87 lm W1
Device structure ITO/[F4-TCNQ(x nm)/m-MTDATA(y nm)]n/NPB/Alq3/Bphen/Cs2CO3/Al [7]
Colour Green green light emitting device
Max. Luminance 23,500 cd/m2
Max. Current Efficiency 7.0 cd/A
Max. Power Efficiency 4.46 lm W1
Device structure ITO/NPB (30 nm)/CBP:8 wt% (t-bt)2Ir(acac)* (15 nm)/
BPhen(35 nm)/LiF (1 nm)/CoPc:C60 (4:1) (5 nm)/
MoO3 (5 nm)/NPB(30 nm)/CBP:8 wt% (t-bt)2Ir(acac)* (15 nm)/
BPhen (35 nm)/Mg:Ag (100 nm) [8]
Colour Yellow yellow light emitting device
Max. EQE 16.78%
Max. Luminance 42,236 cd/m2
Max. Current Efficiency 50.2 cd/A
Max. Power Efficiency 12.9 lm W1
Device structure ITO/NPB (60 nm)/BNA:2 wt% perylene and 0.5 wt% DCJTB* (35 nm)/Alq3 (25 nm)/Mg:Ag (200 nm) [9]
Colour White white light emitting device
Max. Luminance 4,100 cd/m2
Max. Current Efficiency 1.65 cd/A
Device structure ITO (100 nm)/NPB (40 nm)/ADN:C6:DCJTB (30 nm)/Alq (30 nm)/LiF (1 nm)/Al (100 nm)
Colour Red red light emitting device
Max. Luminance 13, 000 cd/m2 [10]
Max. Current Efficiency 4.9 cd/A

*For chemical structure information please refer to the cited references.


1H NMR of N,N′-Di(1-naphthyl)-N,N′-diphenyl-(1,1′-biphenyl)-4,4′-diamine NPB
1H NMR of N,N′-Di(1-naphthyl)-N,N′-diphenyl-(1,1′-biphenyl)-4,4′-diamine (NPB) in CDCl3
HPLC trace of NPB
HPLC trace of N,N′-Di(1-naphthyl)-N,N′-diphenyl-(1,1′-biphenyl)-4,4′-diamine (NPB)


Grade Order Code Quantity Price
Sublimed (>99%) M361 1 g £180
Sublimed (>99%) M361 5 g £480
Unsublimed (>98%) M362 5 g £210

MSDS Documentation


Literature and Reviews

  1. Organic electroluminescent devices with improved stability, S. A. Van Slyke et al., Appl. Phys. Lett. 69, 2160 (1996);
  2. High efficiency white organic light-emitting devices by effectively controlling exciton recombination region, F. Guo et al., Semicond. Sci. Technol. 20, 310–313 (2005).
  3. Manipulating Charges and Excitons within aSingle-Host System to Accomplish Efficiency/CRI/Color-Stability Trade-off for High-PerformanceOWLEDs, Q. Wang et al., Adv. Mater., 21, 2397–2401 (2009).
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