WT8.BZ]The effects of postgrowth rapid thermal annealing have been studied on the optical properties of 3-nm-height InAs/GaAs quantum dots covered by 3-nm-thick In xGa 1-x As (x=0,0 1 and 0 2) overgrowth layer...WT8.BZ]The effects of postgrowth rapid thermal annealing have been studied on the optical properties of 3-nm-height InAs/GaAs quantum dots covered by 3-nm-thick In xGa 1-x As (x=0,0 1 and 0 2) overgrowth layer.At a higher annealing temperature (T≥750℃),the photoluminescence peak of InGaAs layer has been observed at the lower-energy side of InAs quantum-dot peak.In addition,a similar blueshift in photoluminescence (PL) emission energy is observed for all samples when the annealing temperature increases from 650 to 850℃.However,the trend of photoluminescence linewidth towards narrowing is totally different for InAs quantum dots with different In mole fraction in InGaAs overgrowth layer.The results suggest that the intermixing in the lateral direction plays an important role in obtaining a better understanding of the modification of optical properties induced by the rapid thermal annealing.展开更多
The effect of rapid thermal annealing on the optical properties of astrained InAs/InP single quantum well structrure has been investigated in this paper.The luminescence intensity of the quantum well at 8 K was increa...The effect of rapid thermal annealing on the optical properties of astrained InAs/InP single quantum well structrure has been investigated in this paper.The luminescence intensity of the quantum well at 8 K was increased by a factor of 4 and 1.55 meV blue shift of the quantum well photoluminescence peak was observed after annealing at the optimal condition of 700℃ for 5 s. Furthermore,we found that the luminescence efficiency of the deep radiative levels in the samples was also affected by rapid thermal annealing.Our experimental results have demonstrated that Rapid thermal annealing significantly improves the crystalline quality of strained quantum well structures after growth and is an important way for enhancement of the performance of the laser device.展开更多
CoPt-TiO2 nanocomposite films were synthesized by rapid thermal annealing of CoPt/TiO2 multilayers.The effects of TiO2 volume fraction on the microstructure and magnetic properties of the nanocomposite films were stud...CoPt-TiO2 nanocomposite films were synthesized by rapid thermal annealing of CoPt/TiO2 multilayers.The effects of TiO2 volume fraction on the microstructure and magnetic properties of the nanocomposite films were studied.Results showed that the ordering and texture of the L10-CoPt particles did not change with TiO2 content up to 76 vol.% of TiO2.However,the volume of the L10-CoPt particles in the film decreased with an increase in TiO2 content.Increasing TiO2 content effectively reduced the coalescence of magnetic grains when TiO2 content was larger than 56 vol.%.Both the out-of-plane coercivity and remanence ratio of the film decreased slightly with TiO2 content,but the in-plane coercivity and remanence ratio of the film decreased firstly and then increased after TiO2 content was larger than 56 vol.%.The reduction in the coercivity of the film should be due to the reduction in the size of the L10-CoPt particles.The reduction in remanence ratio might be due to the weakening of the exchange coupling strength between the magnetic grains when TiO2 content was increased,as indicated by the MFM images.展开更多
We develop a model for the effect of thermal annealing on forming In--N dusters in GalnNP according to thermodynamics. The average energy variation for forming an In--N bond in the model is estimated according to the ...We develop a model for the effect of thermal annealing on forming In--N dusters in GalnNP according to thermodynamics. The average energy variation for forming an In--N bond in the model is estimated according to the theoretical calculation. Using the model, the added number of In--N bonds per mol of InGaNP, the added number of nearest-neighbor In atoms per N atom and the average number of nearest-neighbor In atoms per N atom after annealing are calculated. The different function of In--N clusters in InGaNP and InGaN is also discussed, which is due to the different environments around the In--N clusters.展开更多
文摘WT8.BZ]The effects of postgrowth rapid thermal annealing have been studied on the optical properties of 3-nm-height InAs/GaAs quantum dots covered by 3-nm-thick In xGa 1-x As (x=0,0 1 and 0 2) overgrowth layer.At a higher annealing temperature (T≥750℃),the photoluminescence peak of InGaAs layer has been observed at the lower-energy side of InAs quantum-dot peak.In addition,a similar blueshift in photoluminescence (PL) emission energy is observed for all samples when the annealing temperature increases from 650 to 850℃.However,the trend of photoluminescence linewidth towards narrowing is totally different for InAs quantum dots with different In mole fraction in InGaAs overgrowth layer.The results suggest that the intermixing in the lateral direction plays an important role in obtaining a better understanding of the modification of optical properties induced by the rapid thermal annealing.
文摘The effect of rapid thermal annealing on the optical properties of astrained InAs/InP single quantum well structrure has been investigated in this paper.The luminescence intensity of the quantum well at 8 K was increased by a factor of 4 and 1.55 meV blue shift of the quantum well photoluminescence peak was observed after annealing at the optimal condition of 700℃ for 5 s. Furthermore,we found that the luminescence efficiency of the deep radiative levels in the samples was also affected by rapid thermal annealing.Our experimental results have demonstrated that Rapid thermal annealing significantly improves the crystalline quality of strained quantum well structures after growth and is an important way for enhancement of the performance of the laser device.
基金supported by the Agency for Science, Technology and Research (ASTAR) Singapore (Grant No. 062-101-0021)FRC of NUS (Grant No. R-284-000-053-112)
文摘CoPt-TiO2 nanocomposite films were synthesized by rapid thermal annealing of CoPt/TiO2 multilayers.The effects of TiO2 volume fraction on the microstructure and magnetic properties of the nanocomposite films were studied.Results showed that the ordering and texture of the L10-CoPt particles did not change with TiO2 content up to 76 vol.% of TiO2.However,the volume of the L10-CoPt particles in the film decreased with an increase in TiO2 content.Increasing TiO2 content effectively reduced the coalescence of magnetic grains when TiO2 content was larger than 56 vol.%.Both the out-of-plane coercivity and remanence ratio of the film decreased slightly with TiO2 content,but the in-plane coercivity and remanence ratio of the film decreased firstly and then increased after TiO2 content was larger than 56 vol.%.The reduction in the coercivity of the film should be due to the reduction in the size of the L10-CoPt particles.The reduction in remanence ratio might be due to the weakening of the exchange coupling strength between the magnetic grains when TiO2 content was increased,as indicated by the MFM images.
基金supported by the Special Funds for the Major State Basic Research Project (Grant No.2011CB301900)the National Natural Science Foundation of China (Grant Nos.60990311,60820106003,60906025,60936004 and 61177078)+1 种基金the Natural Science Foundation of Jiangsu Province (Grant Nos.BK2008019,BK2010385,BK2009255 and BK2010178)the Research Funds from NJU-Yangzhou Institute of Opto-electronics
文摘We develop a model for the effect of thermal annealing on forming In--N dusters in GalnNP according to thermodynamics. The average energy variation for forming an In--N bond in the model is estimated according to the theoretical calculation. Using the model, the added number of In--N bonds per mol of InGaNP, the added number of nearest-neighbor In atoms per N atom and the average number of nearest-neighbor In atoms per N atom after annealing are calculated. The different function of In--N clusters in InGaNP and InGaN is also discussed, which is due to the different environments around the In--N clusters.
