Volume 7, Issue 1 (International Journal of Optics and Photonics (IJOP) Vol 7, No 1, Winter-Spring 2013)                   IJOP 2013, 7(1): 11-18 | Back to browse issues page

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Abstract:   (14455 Views)

In this research, the lifetime of green organic light emitting diodes (OLEDs) is studied using four passivation layers. To encapsulate the OLEDs, MgF2, YF3, composed of alternating MgF2/ZnS and YF3/ZnS layers were grown by thermal vacuum deposition. Measurements show that the device lifetime is significantly improved by using YF3 and ZnS as passivation layers. However, diodes encapsulated by MgF2/ZnS and YF3/ZnS nano-structures show a highly efficient gas diffusion barrier that results in a longer lifetime of the devices. The half lifetime of the green OLEDs reached 1200 minutes using YF3/ZnS layers. The electroluminescence (EL) and current-voltage characteristics of the devices were also examined to compare the electrical and the emissivity properties of the devices before and after encapsulation. This simple and inexpensive thin-film encapsulation method would be potentially employed to capsulate top emitting OLEDs and flexible OLEDs due to their good performance and easy fabrication.

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Type of Study: Research | Subject: General
Received: 2013/06/26 | Revised: 2015/02/24 | Accepted: 2013/11/6 | Published: 2014/03/12