Determination of localized-state distributions in organic light-emitting diodes by impedance spectroscopy

2009 ◽  
Vol 94 (4) ◽  
pp. 043301 ◽  
Author(s):  
Takayuki Okachi ◽  
Takashi Nagase ◽  
Takashi Kobayashi ◽  
Hiroyoshi Naito
Keyword(s):  
Impedance Spectroscopy ◽  
Light Emitting Diodes ◽  
Organic Light Emitting Diodes ◽  
Light Emitting ◽  
Localized State ◽  
Organic Light

Degradation of Bilayer Organic Light-Emitting Diodes Studied by Impedance Spectroscopy

2016 ◽  
Vol 16 (4) ◽  
pp. 3368-3372 ◽  
Author(s):  
Shuri Sato ◽  
Masashi Takata ◽  
Makoto Takada ◽  
Hiroyoshi Naito
Keyword(s):  
Impedance Spectroscopy ◽  
Light Emitting Diodes ◽  
Device Simulation ◽  
Hole Transport ◽  
Organic Light Emitting Diodes ◽  
Transport Layer ◽  
Electron Transport Layer ◽  
Hole Transport Layer ◽  
Light Emitting ◽  
Organic Light

The degradation of bilayer organic light-emitting diodes (OLEDs) with a device structure of N, N′-di(1-naphthyl)-N, N′-diphenylbenzidine (α-NPD) (hole transport layer) and tris-(8-hydroxyquinolate)aluminum (Alq3) (emissive layer and electron transport layer) has been studied by impedance spectroscopy and device simulation. Two modulus peaks are found in the modulus spectra of the OLEDs below the electroluminescence threshold. After aging of the OLEDs, the intensity of electroluminescence is degraded and the modulus peak due to the Alq3 layer is shifted to lower frequency, indicating that the resistance of the Alq3 layer is increased. Device simulation reveals that the increase in the resistance of the Alq3 layer is due to the decrease in the electron mobility in the Alq3 layer.

Sign in / Sign up

Export Citation Format

Share Document