GaN-Based Green-Light-Emitting Diodes with InN/GaN Growth-Switched InGaN Wells

Abstract

We have demonstrated the InN/GaN growth switching of the InGaN wells of green-light-emitting diodes (LEDs). The output power of green LEDs with InN/GaN growth-switched InGaN wells (120 mA) changed by approximately 23% compared with that of green LEDs with conventional InGaN wells. However, the emission wavelength blue shift and efficiency drops of green LEDs with InN/GaN growth-switched InGaN wells (15.0 nm and 44.6%, respectively) are larger than those of green LEDs with conventional InGaN wells (10.5 nm and 30.7%, respectively).

Localization and defects in axial (In,Ga)N/GaN nanowire heterostructures investigated by spatially resolved luminescence spectroscopy

“…That is, the linewidth locally recorded on one insertion is of a similar magnitude as the integral luminescence of planar QW structures [41,42]. Another observed feature is the emission at slightly higher energy than the main peaks visible in figures 6(d) and (f) between 2.5 and 2.8 eV.…”

“…For single (In,Ga)N insertions, Tourbot et al [18] observed an FWHM of 200 meV in TEM-based CL measurements, which is comparable to our results. That is, the linewidth locally recorded on one insertion is of a similar magnitude as the integral luminescence of planar QW structures [41,42]. Another observed feature is the emission at slightly higher energy than the main peaks visible in figures 6(d) and (f) between 2.5 and 2.8 eV.…”

“…However, the emission bands of individual NWs remain rather broad with an FWHM of 200-300 meV. In contrast, values for the FWHM on the order of 100-150 meV are reported from PL on planar (In,Ga)N QW structures emitting in the green spectral range [41,42]. These features call for a closer investigation of the (In,Ga)N luminescence of single NWs in CL spectral maps.…”

Effective suppression of efficiency droop in GaN-based light-emitting diodes: role of significant reduction of carrier density and built-in field

“…The former can be explained by the screening effect of internal electric field, while the latter by the band filling effect. Generally, as the screening effect of the internal electric field in QWs dominates, the reduction of FWHM is accompanied 24 . The decreasing trend in FWHM was appeared to reduce more obviously from sample I to sample III, implying that the internal electric field in QWs decreases as d barrier decreases.…”

Effect of small flow hydrogen treatment at the upper well/barrier interface on the properties of InGaN/GaN multiple quantum wells

“…Elevating the growth temperature of GaN quantum barrier (QB) is found to be an effective way to improve the quality of active region [13]. Although the growth temperature of QB is usually 50-150 higher than that of QW, it is still [14,15], growth interruption [16,17] and indium treatment [18][19][20]. Recently, Ren et al demonstrated that full hydrogen treatment after GaN barrier layer growth can enhance both indium incorporation and quantum efficiency [21].…”