We report the results of the morphological, electrical and optical characterisation of double-layer Alq3-based organic emitting diodes with a lithium fluoride (LiF)/Al cathode. A detailed electron microscopy investigation of their cross-section shows the presence of LiF isolated grains underneath the Al film. Due to the introduction of the LiF layer, luminance was larger than 30,000cd/m2 at a bias voltage VB=25V with a maximum external luminous efficiency as large as 46lm/W at VB=20V. Performing on/off VB cycles at a very low frequency, each time a recovery of the initial electric and luminous performance was observed. The non-exponential decay of both electric current and luminance during each on-cycle has been interpreted as the signature of dispersive transport controlled by multiple trapping on localised states in an amorphous system. © 2004 Elsevier B.V. All rights reserved.
Morphological, electrical and optical properties of organic light-emitting diodes with a LiF/Al cathode and an Al-hydroxyquinoline/diamine junction / R. M., Montereali; S., Gambino; S., Loreti; S., Gagliardi; A., Pace; G., Baldacchini; Michelotti, Francesco. - In: SYNTHETIC METALS. - ISSN 0379-6779. - STAMPA. - 143:2(2004), pp. 171-174. [10.1016/j.synthmet.2003.11.008]
Morphological, electrical and optical properties of organic light-emitting diodes with a LiF/Al cathode and an Al-hydroxyquinoline/diamine junction
MICHELOTTI, Francesco
2004
Abstract
We report the results of the morphological, electrical and optical characterisation of double-layer Alq3-based organic emitting diodes with a lithium fluoride (LiF)/Al cathode. A detailed electron microscopy investigation of their cross-section shows the presence of LiF isolated grains underneath the Al film. Due to the introduction of the LiF layer, luminance was larger than 30,000cd/m2 at a bias voltage VB=25V with a maximum external luminous efficiency as large as 46lm/W at VB=20V. Performing on/off VB cycles at a very low frequency, each time a recovery of the initial electric and luminous performance was observed. The non-exponential decay of both electric current and luminance during each on-cycle has been interpreted as the signature of dispersive transport controlled by multiple trapping on localised states in an amorphous system. © 2004 Elsevier B.V. All rights reserved.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
