en عمومى General پژوهشي Research <p><font face="times new roman,times,serif" size="2">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.</font></p> MgF2, OLEDs, Thin-film encapsulation, YF3, ZnS 11 18 http://ijop.ir/browse.php?a_code=A-10-387-4&slc_lang=en&sid=1 Maral Ghoshani 10031947532846002268 10031947532846002268 No Abbas Behjat abehjat@yazd.ac.ir 10031947532846002269 10031947532846002269 Yes Fatemeh Jafari 10031947532846002270 10031947532846002270 No Naimeh torabi 10031947532846002271 10031947532846002271 No