This paper presents metalorganic chemical vapour deposition (MOCVD) growth of GaAs / Al_x Ga_(1-x) Assuperlattices and their application in HEMT (high electron mobility transistor). SEED (self eletrooptic ef-fect devi...This paper presents metalorganic chemical vapour deposition (MOCVD) growth of GaAs / Al_x Ga_(1-x) Assuperlattices and their application in HEMT (high electron mobility transistor). SEED (self eletrooptic ef-fect device) devices. Superlattice structures are characterized by using crosssectional transmission electronmicroscopy (XTEM). X-ray diffraction and low temperature photoluminescence (PL), and the results showthat they are in agreement with the designed parameters. The superlattice used as buffer layer in HEMTcan smooth out interface roughness. This smoothing effect is related to the migration of Ga and Al specieson the growing surface and the anisotropic growth rate of GaAs on different facets. High qualitysuperlattice with 27 satellite peaks measured by X- ray diffraction is obtained. Based on the structureparameters determined by TEM and X- ray diffraction. the calculated emission peak position of thesuperlattice is in agreement with PL results.展开更多
When the GaAs/AlGaAs superlattice-based devices are used under irradiation environments, point defects may be created and ultimately deteriorate their electronic and transport properties. Thus, understanding the prope...When the GaAs/AlGaAs superlattice-based devices are used under irradiation environments, point defects may be created and ultimately deteriorate their electronic and transport properties. Thus, understanding the properties of point defects like vacancies and interstitials is essential for the successful application of semiconductor materials. In the present study, first-principles calculations are carried out to explore the stability of point defects in GaAs/Al_(0.5)Ga_(0.5)As superlattice and their effects on electronic properties. The results show that the interstitial defects and Frenkel pair defects are relatively difficult to form, while the antisite defects are favorably created generally. Besides, the existence of point defects generally modifies the electronic structure of GaAs/Al_(0.5)Ga_(0.5)As superlattice significantly, and most of the defective SL structures possess metallic characteristics. Considering the stability of point defects and carrier mobility of defective states,we propose an effective strategy that AlAs, GaAs, and AlGaantisite defects are introduced to improve the hole or electron mobility of GaAs/Al_(0.5)Ga_(0.5)As superlattice. The obtained results will contribute to the understanding of the radiation damage effects of the GaAs/AlGaAs superlattice, and provide a guidance for designing highly stable and durable semiconductor superlattice-based electronics and optoelectronics for extreme environment applications.展开更多
文摘This paper presents metalorganic chemical vapour deposition (MOCVD) growth of GaAs / Al_x Ga_(1-x) Assuperlattices and their application in HEMT (high electron mobility transistor). SEED (self eletrooptic ef-fect device) devices. Superlattice structures are characterized by using crosssectional transmission electronmicroscopy (XTEM). X-ray diffraction and low temperature photoluminescence (PL), and the results showthat they are in agreement with the designed parameters. The superlattice used as buffer layer in HEMTcan smooth out interface roughness. This smoothing effect is related to the migration of Ga and Al specieson the growing surface and the anisotropic growth rate of GaAs on different facets. High qualitysuperlattice with 27 satellite peaks measured by X- ray diffraction is obtained. Based on the structureparameters determined by TEM and X- ray diffraction. the calculated emission peak position of thesuperlattice is in agreement with PL results.
基金Project supported by the NSAF Joint Foundation of China (Grant No. U1930120)the Key Natural Science Foundation of Gansu Province, China (Grant No. 20JR5RA211)the National Natural Science Foundation of China (Grant No. 11774044)。
文摘When the GaAs/AlGaAs superlattice-based devices are used under irradiation environments, point defects may be created and ultimately deteriorate their electronic and transport properties. Thus, understanding the properties of point defects like vacancies and interstitials is essential for the successful application of semiconductor materials. In the present study, first-principles calculations are carried out to explore the stability of point defects in GaAs/Al_(0.5)Ga_(0.5)As superlattice and their effects on electronic properties. The results show that the interstitial defects and Frenkel pair defects are relatively difficult to form, while the antisite defects are favorably created generally. Besides, the existence of point defects generally modifies the electronic structure of GaAs/Al_(0.5)Ga_(0.5)As superlattice significantly, and most of the defective SL structures possess metallic characteristics. Considering the stability of point defects and carrier mobility of defective states,we propose an effective strategy that AlAs, GaAs, and AlGaantisite defects are introduced to improve the hole or electron mobility of GaAs/Al_(0.5)Ga_(0.5)As superlattice. The obtained results will contribute to the understanding of the radiation damage effects of the GaAs/AlGaAs superlattice, and provide a guidance for designing highly stable and durable semiconductor superlattice-based electronics and optoelectronics for extreme environment applications.
