Investigate Of InAs/GaAs Quantum Dots Photoluminescence Under External Field Conditions

In 1833,Faraday,a British scientist,discovered the semiconductor nature of silver sulfide which resistance decreased with the temperature increasing.There are initiating the research about the semiconductor materials.The research and development of semiconductor technology has much profound impacts for society.The single photo source based on discrete semiconductor self-organized quantum dots is a good choice.Because it has an series of advantages.For example,higher brightness,narrow line width,short life and easy integration.So it has important scientific research value and broad application prospects.With the development of the growth process,the second-generation semiconductor self-organized quantum dots single photo source has become mature.And the indium arsenide/ arsenide gallium(In As/Ga As)quantum dots are symbol of single photo source.It is a direct band gap semiconductor material with higher luminous efficiency and electron mobility,so it is can be used to make high-performance microwave and millimeter wave devices.And it has widely applied in satellite communication and optical communication.At persent,the method for preparing In As/Ga As quantum dots is molecular beam epitaxy(MBE),and high-quality samples are prepared by precisely controlling the growth process and growth parameters.On the other hand,it is inevitable to encounter various environmental requirements in the use of quantum dot devices,such as high temperature soldering,position fixing,integrated assembly,etc..There are have a certain impact on the performance of quantum dots,and scholars continue to pay attention to and study this issue.However,there are few studies on the optical properties of samples after deformation.But it is difficult to avoid during the processing of quantum dot devices.Therefore,it has scientific value to study the optical properties of quantum dot samples after deformation.In this paper,the samples that we used are In As/Ga As quantum dots sample prepared on Ga As substrate using the MBE.First,all samples were tested for surface topography using atomic force microscopy(AFM).Simultaneously,we obtain the size and density distribution of quantum dots on the surface of the sample.Then,the Raman spectrum of all samples at room temperature and the photoluminescence spectrum of different temperatures(90k-300k)were measured by confocal raman spectroscopy.It was found that as the test temperature increased,the corresponding spectrum of the sample red-shifted and the spectral intensity decreased.Finally,when the test temperature and excitation power are suitable,select a sample with better spectral signal,measure the fluorescence spectrum image after applying slight strain to the sample(0.5%),and compare it with the spectrum of the sample without strain,and find the substrate.It was found that the peak position of the PL corresponding to the substrate was weakly red-shifted,and the peak position of the corresponding line of the wetting layer did not change.But the intensity was increases,and the spectrum corresponding to the quantum dots undergoes a weak blue shift,and its luminous intensity decreases.