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利用常压MOCVD技术在较低生长速率下生长出多种GaAs/AlGaAs多量子阱结构材料,利用低温PL谱和TEM对材料结构进行了表征。所得势阱和势垒结构厚度均匀平整,最窄阱宽为1.8nm。本研究表明,低速率(γ≤0.5nm/s)连续生长工艺能够避免杂质在界面富集,优于间断生长工艺,且在掺si n~+-GaAs衬底上所得量子阱发光强度高于掺Cr SI-GaAs衬底上的结果。 相似文献
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对MOCVD生长的GaAs(40)/AlxGa(1-x)As(300)多量子阱结构观察到附内电子从基态到第一激发态跃迁引起的红外吸收.用Bruker红外光谱仪测量,发现了一个峰值在986cm-1(10.1μm)带宽为237cm-1(9~11.5μm)的强吸收峰,该峰位置与阱内电子从基态到第一激发态跃迁所计算的吸收峰位置基本一致. 相似文献
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The MOCVD growth of modified AlAs/GaAs double barrier resonant tunneling diodes(DBRTD)withan A1GaAs chair was reported.The resonances to the first excited states were obtained.The peak-to-valley cur-rent ratio(PVCR)is 1.3 at 77K,room temperature peak current density is 8 kA/cm~2.The resonance voltagesare in agreement with the theoretical approach by transfer-matrix method.Influence of interrupted growthtime at the hetero-interface and incorporation of the AlGaAs chair to the device performances were studiedand the mechanism was discussed.The attempt to add an AlGaAs chair to the DBRTD by MOCVD resultedin improvement in the PVCR and peak current density. 相似文献
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This paper presents Atmospheric Pressure Metalorganic Chemical Vapor Deposition(AP-MOCVD)growth of GaAs/Al-xGa_(1-x)As multiquantum wells for the study of intersubband transition.The multiplequantum well structures are characterized by using cross-sectional transmission electron microscopy(TEM)and low temperature photoluminescence(PL),which are in consistent with the designed parameters.The in-frared absorption from intersubband transitions between the bounded- ground state and the extended excitedstate in GaAs/AtGaAs quantum wells shows peak at 10 μm with FWHM 250 cm~(-1).The absorption peakpositions are in agreement with the calculated results based on the envelope function approximation. 相似文献