Dominant factors determining the threshold voltage for thin film electroluminescent devices

A description is given of the causes of electric field clamping for thin-film electroluminescent (TFEL) devices. It is shown that clamped electric fields are highly dependent on emission-layer conductivity as well as on crystallinity. Clamped electric field strengths decrease with increases on conductivity, which can be controlled by emission-layer preparation methods and growth conditions. The clamping mechanism is also discussed. It is shown that the TFEL devices having low resistive emission layers produce more Joule heat and the electric field is clamped at a lower electric field strength.<
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