| Since silicon and germanium are widely used as the first type of semiconductors,the development of semiconductor science and the deepening application of semiconductor technology have had a profound impact on all aspects of human society.Since the 1960 s,physicists have realized that studying quantum effects in ultra-thin materials has great advantages,and the emergence of quantum dot materials provides research targets for further exploring the quantum confinement effect of materials.Since the 1980 s,the emergence of growth processes such as organometallic chemical vapor deposition(MOCVD)and molecular beam epitaxy(MBE)has provided effective methods for preparing high-precision self-assembled quantum dots.As an excellent direct bandgap material,In As quantum dots have many advantages such as narrow bandgap,high luminous efficiency,high electron mobility,excellent stability and so on.At present,people have done a lot of research on the changes of quantum dot physical properties under growth conditions,composition,quantum dot surface morphology,temperature during measurement,excitation light power and other conditions.In the research process of In As quantum dots,I.E.Itskevich,Ma Baoshan and others have done a lot of research on the effect of hydrostatic pressure on the optical properties of In As quantum dots.It is found that hydrostatic pressure will lead to the decrease of fluorescence spectral intensity of In As quantum dots and the change of pressure coefficient.However,little research has been done on the changes of optical properties of In As quantum dots when semiconductor devices are deformed due to stress.However,semiconductor materials will not only generate stress due to lattice mismatch and other reasons in the preparation process,but also semiconductor devices need to face various external environments such as splicing,assembly and fixation,device integration and so on during the preparation and use.Deformationcaused by external stress will certainly exist,which will also have certain influence on the performance of quantum dots.Therefore,it is of great guiding significance to study the physical properties and optical changes of quantum dots samples after deformation.In this paper,In As/Ga As quantum dots prepared on Ga As substrates are studied.Using effective mass approximation method and piezoelectric electronics theory,the influence of external stress on band width and curvature of quantum dot materials is considered,and the changes of optical properties of cylindrical In As/Ga As quantum dots under external conditions such as stress and temperature are theoretically analyzed.The results show that stress will reduce the intensity of light absorption lines of quantum dots.However,the resonance peak shifts blue and the energy increases.At the same time,when the pressure potential caused by stress is considered,the decrease of spectral line intensity is more obvious.The formant position still moves towards high energy,but compared with the case without considering the voltage potential,the blue shift decreases and the change weakens.The increase of temperature will lead to the decrease of formant peak energy and the decrease of the relative intensity of spectral lines.The experiment was completed under the condition that the measured temperature was 110 K and 0.5% strain was applied to the material.It was found that the experimental results were in good agreement with the theoretical calculation when the combined influence of stress and temperature was comprehensively considered.Comparing the calculated results with the experimental data,the theoretical analysis has been verified.These results are of great help to the research and application of quantum dot optoelectronic devices in different working environments. |
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