Free electron laser is a new type of laser, which is stimulated radiation generated by the relativistic electron beam when it passes through the rocker. Compared with conventional lasers, it has a series of outstanding advantages such as continuously adjustable wavelength, wide coverage, high output peak power, fine and plastic pulse structure, and good beam quality. It has a wide range of potential applications in the field of semiconductors and microelectronics. prospect. Irradiation of semiconductor materials with free electron laser pulses of appropriate wavelength and extremely high peak power can change the internal structure of the material, thereby achieving the purpose of changing the physical properties of the material. As a new type of radiation source, studying the influence of its radiation effect on the optical properties of quantum well materials is of great significance for improving the photoelectric performance of infrared detectors and other optoelectronic devices. At present, the research on the irradiation effect of GaAs / AlGaAs multiple quantum wells mainly focuses on the new results of different irradiation of charged particles. This article discusses this situation and compares it with electron irradiation. The results show that the irradiation of free electron laser can change the atomic distribution of GaAs / AlGaAs multi-quantum well materials, so as to fine-tune the energy level distribution of quantum wells.
2 Sample preparation and irradiation. Funding projects on n-type heavily doped GaAs substrates: the National Natural Science Foundation of China (No. 008802) and the National University Doctoral Point Fund.
―), Male, master, mainly engaged in the research work of the design of semiconductor materials, devices and integrated circuits. E-mailzoumihotmaiLcom grows a 200nm thick GaAs buffer layer, and then extends a 30-cycle quantum well above it, where the GaAs potential well is 10nm thick, the Al.3Ga.7As barrier is 20nm thick, and finally the top layer is 50nm thick GaAs protective layer.
Free electron laser irradiation was performed on the free electron laser device (BFEL) of the Institute of High Energy Physics, Chinese Academy of Sciences. The irradiation conditions are: at room temperature, the multi-quantum well is irradiated with a free electron laser with a wavelength of 8.92Mm, a macro pulse energy of 1.29m, a spot diameter of 3.69mm, which corresponds to a laser field strength of 20kV / cm, and each There are 3 macro pulses per second. The sample was irradiated with electron beam on a type 2 electrostatic accelerator. Curve 1 is the fluorescence spectrum of the sample before irradiation. The fluorescence peak with a wavelength of 797 nm corresponds to the n = electricity in the conduction band of the quantum well.
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