Application of GaN Pressure Grown Crystals for Epitaxy of GaN-Based Structures |
I. Grzegory High Pressure Research Center, Polish Academy of Sciences SokoĊowska 29/37, 01-142 Warsaw, Poland |
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The results obtained with the use of the pressure grown GaN single crystalline substrates allow to draw the following conclusions important for the construction of In-free UV light emitting diodes and lasers and InGaN-based high power blue lasers: 1. The application of the pressure grown GaN single crystalline substrates allows to grow near dislocation free layer structures by both metal organic chemical vapor deposition and MBE. 2. The elimination of dislocations leads to highly efficient UV emission from GaN and GaN/AlGaN quantum wells which is impossible for strongly dislocated structures grown on sapphire. 3. At high excitations (i.e. in lasers) dislocations are effective nonradiative recombination centers also in the InGaN containing structures, therefore the elimination of these defects is crucial for better performance of blue lasers. 4. The analysis of microstructural and optical properties of the InGaN containing dislocation free structures shows that the main mechanisms of carrier localization in InGaN are not related with the nm scale compositional fluctuations in InGaN. In the paper, the optical and structural properties of the near dislocation free GaN-based structures leading to the above conclusions are discussed. |
DOI: 10.12693/APhysPolA.98.183 PACS numbers: 81.10.-h, 81.05.Dz, 73.61.Ey, 78.66.Fd |