Photoluminescence Dynamics of InGaN/GaN Quantum Wells with Different In Concentrations

✍ Scribed by M. Klose; K.P. Korona; J. Kuhl; M. Heuken

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 204 KB
• Volume: 216
• Category: Article
• ISSN: 0370-1972
• DOI: 10.1002/(sici)1521-3951(199911)216:1<325::aid-pssb325>3.0.co;2-w

✦ Synopsis

The photoluminescence (PL) dynamics of InGaN/GaN quantum wells with different In concentrations x In have been measured. The PL emission forms a broad band consisting of two parts with dramatically different dynamics. The high energy part (QW H ) is present only under higher excitation densities (>10 3 W/cm 2 ), it has fast decay (of a few tens of ps) and changes only slightly with temperature. Its relative amplitude and the PL lifetime t increase with the x In . The second, low energy part (QW L ) has slow decay (of the order of 10 ns), its amplitude saturates under higher excitation densities and quickly vanishes when the temperature increases. At 10 K the QW L lifetimes change from t = 1.8 AE 0.2 ns (x In = 0.11) up to 20 AE 4 ns (x In = 0.4) while the thermal activation energy (E a = 18 AE 3 meV) is not sensitive for the In concentration. We propose that QW H and QW L come from nonlocalised and localised carrier recombination, respectively.