AVS 54th International Symposium | |
Thin Film | Friday Sessions |
Session TF1-FrM |
Session: | Thin Films for Displays and Flexible Electronics |
Presenter: | P.H. Holloway, University of Florida |
Authors: | D.M. DeVito, University of Florida A.A Argun, University of Florida E.S. Law, University of Florida M. Puga-Lambers, Microfabritech M.R. Davidson, Microfabritech P.H. Holloway, University of Florida |
Correspondent: | Click to Email |
ZnS:ErF3 alternating current thin film electroluminescent (ACTFEL) devices were fabricated by RF plasma magnetron sputtering. In a full factorial design-of-experiment study, increasing deposition temperature, duty cycle on the doped target and sputter gas pressure all resulted in increases in the 1.55 µm near infrared (NIR) electroluminescence (EL) irradiance at 20V above threshold (B20). An increase in the EL threshold voltage (Vth) upon increasing the duty cycle of the undoped target was also observed. Post-deposition annealing of ACTFEL devices at 425°C for 1 hr improved the NIR EL irradiance by decreasing the F concentrations in the ZnS:Er films. The origins of these effects are discussed in terms of negative ion resputtering, surface mobility of sputtered species, crystallinity, and the effects of atomic concentration upon the EL and radiative relaxation processes. A maximum irradiance, B20, of 147 µW/cm2 is measured for the 1.55 µm NIR EL peak from a ZnS:Er ACTFEL devices produced using a deposition temperature of 150°C, a duty cycle of 75%, an argon sputtering gas pressure of 24 mTorr and post-deposition annealing at 425°C for 1 hour in nitrogen.