Electroluminescent properties of erbium-doped III–N light-emitting diodes

Abstract

We report on the synthesis of Er-doped III–N double heterostructure light-emitting diodes (LEDs) and their electroluminescence (EL) properties. The device structures were grown through a combination of metalorganic chemical vapor deposition (MOCVD) and molecular-beam epitaxy (MBE) on c-plane sapphire substrates. The AlGaN layers, with an Al concentration of ∼12%, were prepared by MOCVD and doped with Si or Mg to achieve n- and p-type conductivity, respectively. The Er+O-doped GaN active region was grown by MBE and had a thickness of 50 nm. The Er concentration was estimated to be ∼1018 cm−3. The multilayer n-AlGaN/GaN:Er/p-AlGaN structures were processed into LEDs using standard etching and contacting methods. Several different LEDs were produced and EL spectra were recorded with both forward and reverse bias conditions. Typically, the EL under reverse bias was five to ten times more intense than that under forward bias. The LEDs displayed a number of narrow emission lines representative of the GaN:Er system (green: 539 nm, 559 nm; infrared: 1000 nm, 1530 nm). While some current crowding was observed, green emission was visible under ambient room conditions at 300 K. At cryogenic temperatures, the emission lines increased in intensity and had a narrower linewidth. EL spectra were recorded down to 10 K and the L-I characteristics were systematically measured. The power output of the brightest LEDs was approximately 2.5 W/m2 at 300 K.

Efficient tight-binding approach for the study of strongly correlated systems

“…Er Ga can be used for testing since the RE Ga substitutionals are the simplest stable lanthanide defects in GaN and have been already studied both experimentally and theoretically. [46][47][48] Er:GaN based light emitting diodes 49 have stimulated many experimental attempts to understand 58 the mechanisms underlying the emission from Er-doped samples and to exploit [51][52][53] and improve 54,55 the emission itself. From experimental studies, we know that Er ions in GaN prefer the Ga position, 56 occur in 3+ valence state 49 and possess C 3v symmetry 57 with relatively short distances to the surrounding N ligands.…”

Carrier lifetime in erbium-doped GaN waveguide emitting in 1540 nm wavelength

“…Optical emission in 1.55 m wavelength window in Er-doped GaN films has been observed. [6][7][8][9] In particular, GaN and AlGaN epilayers doped with Er-ions have demonstrated a highly reduced thermal quenching of the Er luminescence intensity from cryogenic to elevated temperatures as compared to other semiconductor host materials such as Si and GaAs. Optical amplification in Er-doped GaN waveguide has also been demonstrated using a 365 nm light emitting diode optical pumping source.…”

Effect of Si and Er Co-doping on Green Electroluminescence from GaN:Er ELDs

“…Subsequently, visible and IR EL emission from GaN:Er Schottky diodes was reported [4] on Si and sapphire substrates. Zavada et al [5] reported EL emission from GaN:Er P-I-N LED on sapphire. In general, in all of these devices the EL emission was much stronger in reverse bias than in forward bias.…”