Low-voltage GaN:Er green electroluminescent devices

Green light emission has been measured from Er-doped GaN electroluminescent devices (ELDs) at an applied bias as low as 5 V. The GaN–Er ELDs were grown by solid source molecular beam epitaxy on Si (111) substrates. We have achieved this low-voltage operation (ten-fold reduction in optical turn-on voltage) by using heavily doped (∼0.01 Ω cm) Si substrates and by decreasing the GaN–Er layer thickness to several hundred nanometers. A simple device model is presented for the indium tin oxide/GaN–Er/Si/Al ELD. This work demonstrates the voltage excitation efficiency of Er3+ luminescent centers and the compatibility of GaN rare earth-doped ELDs with low-voltage drive circuitry.