Photoluminescence of GaN/AlN superlattices grown by MOCVD

Abstract

We report on the emission properties of GaN/AlN superlattice (SL) structures grown by MOCVD. A set of samples with AlN thickness below 3 nm and different well/barrier thickness ratios has been studied. The SLs with a period between 3 and 8 nm show a photoluminescence (PL) peak in the range 3.3-3.9 eV with a full width at half maximum of about 100 meV. The difference in the transition energies, linewidths and recombination dynamics is described in terms of varying polarization field and electron filling in the wells.

Influence of the structural inhomogeneity on the luminescent properties of nitride multiple quantum wells grown by MOCVD

“…The optical properties of such structures are greatly affected by the presence of macroscopic polarization in the layers. Another important factor that influences the optical properties is the interface roughness, which is manifested as wells with fluctuations [5][6][7].…”

“…The optical properties of such structures are greatly affected by the presence of macroscopic polarization in the layers. Another important factor that influences the optical properties is the interface roughness, which is manifested as wells with fluctuations [5][6][7].In this study, we examined by means of cathodoluminescence an InGaN/GaN multiple quantum well (MQW) grown by MOCVD on a GaN substrate. All measurements were conducted at room temperature.…”

Tunneling effects in short period strained AlN/GaN superlattices

“…Photoluminescence measurements [13] reveal emission below the GaN band gap, which reflects the high built-in field in the AlN/GaN system. The measured transition energy is influenced by the competition between the blue shift induced by quantum confinement and red shift influenced by polarization.…”

“…The built-in electric field in the wells 2.7 MV/cm is estimated according to the approach in [12,13]. As a result a bound positive sheet charge occurs at the AlN/GaN interface, which attracts mobile electrons, and a two-dimensional electron gas (2DEG) is formed even in the absence of any intentional doping.…”

Novel HVPE technology to grow nanometer thick GaN, AlN, AlGaN layers and multi‐layered structures

“…The 3.515 eV peak is blueshifted by about 40 meV as compared to the dominant exciton peak in thick GaN layers, which are attributed to the quantum confinement effect. From the peak position we roughly estimate that the width of the QWs is about 3-4 nm [7][8][9]. The relatively small width of the 3.515 eV peak (the FWHM is 30-40 meV) is indicative of the high quality of QWs and narrow distribution of their widths.…”