Spectroscopic Studies in InGaN Quantum Wells

EXCITON LOCALIZATION IN InGaN/GaN QUANTUM WELLS

Time-resolved cathodoluminescence (CL) techniques have been employed to examine the optical properties and kinetics of carrier relaxation in a InGaN/GaN single quantum well (QW) sample. CL images of the QW sample revealed a spotty cellular pattern indicative of local In compositional variations, which induce local potential fluctuations and result in a strong lateral excitonic localization at I...

Photoluminescence microscopy of InGaN quantum wells

Submicron spatial resolution photoluminescence is used to assess radiative efficiency and spatial uniformity of GaN/InGaN heterojunctions. Room temperature photoluminescence of multiple InGaN quantum wells with GaN barriers fabricated by electron-cyclotron resonance assisted molecular beam epitaxy was measured as a function of position on a facet perpendicular to the layer structure. Our high r...

Investigation of strain effect in InGaN/GaN multi-quantum wells

The strain effect of InGaN/GaN multi-quantum wells with different indium contents has been studied in the present paper. The high-resolution X-ray diffraction (HRXRD) curves of the samples have been measured and analyzed by a theoretical model. Based on the model, it is found that sample with higher indium content exhibits a stronger internal strain. To further investigate the calculated result...

Phase separation in annealed InGaN/GaN multiple quantum wells

In-rich second phases were detected by transmission electron microscopy (TEM) in In 0.27 Ga 0.73 N multiple quantum well (MQW) samples that were annealed at 950°C for 40 h. X-ray diffraction (XRD) measurements showed a shift in the zero-order diffraction peak toward GaN, consistent with the formation of an In-poor phase remaining in the InGaN wells. Voids were also found by TEM in the MQWs afte...

Dynamics of localized excitons in InGaN/GaN quantum wells