Alternating current thin-film electroluminescence of GaN:Er

Thin-film electroluminescence has been obtained from GaN:Er deposited directly on amorphous dielectric layers. Electroluminescent device (ELD) structures consisting of metal/dielectric/GaN:Er/dielectric were fabricated on p(+)-Si substrates. In contrast to previous GaN:Er ELDs which used epitaxial growth conditions on crystalline substrates and were operated under direct current bias, these ELDs were operated under alternating current bias. Under bias conditions of 170 peak voltage (V-p) and frequencies of 10 and 100 kHz, the ELDs exhibit a luminance of 50 and 300 cd/m(2), respectively. The emission spectra, which originate from Er3+ 4f-4f transitions, consist of dominant green emission at similar to 537/558 nm accompanied by violet (415 nm) and infrared (1.5 mum) peaks. The violet emission peak indicates that hot carriers can gain up to similar to3 eV energy for a V-p corresponding to 1.5 MV/cm applied field. The emitted intensity initially increases linearly with frequency, followed by a trend towards saturation. The frequency for 3 dB reduction from the linear relation is at similar to 65 kHz for the visible emission and similar to8 kHz for the infrared emission. (C) 2000 American Institute of Physics. [S0003-6951(00)04749-5].