InGaN/GaN Quantum Dots --- Growth, Nano-Structure Material Analysis, and Optical Characterization
Abstract
We compare the result of strain state analysis (SSA) and photoluminescence (PL) of six InGaN/Gan quantam well samples with un-doped, well-doped, and barrier-doped structures. Based on SSA images, a strain relaxation model is proposed for describung the nanostructure differences between the three sets of sample of different doping conditions. In the barrier-doped samples, the hetero-structure-induced. Therefore, strongly clustering nanostructures (quantum dots) are observed. In the well-doped samples, strain are partially relaxed and the spinodal decompositions are observed. Then, in the Un-doped samples, the un-relaxed strains result in higher miscibility between InN and GaN, Leading to the relatively more uniform composition distributions. Between the Low- and high-indium samples, higher indium content leads to a stronger clustering behavior. The strain relaxations in the well-doped and barrier-doped samples result in their unclear S-Shape behaviors of PL spectral peaks. The enhaused carrier localization and reduced quantum-confined stark effect in the barrier-doped samples are responsible for their significant increases of radiative efficiency.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 27, 2005
- Accession Number
- ADA473155
Entities
People
- Chih-Chung Yang
Organizations
- National Taiwan University