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Title: The pressure and temperature dependencies of the Gunn and lasing thresholds in (GaIn) (AsP) semiconductor devices
Author: Heasman, Keith C.
ISNI:       0000 0001 3551 2389
Awarding Body: University of Surrey
Current Institution: University of Surrey
Date of Award: 1985
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16 cm-3 n-doped LPE grownGaxIn1-xAsyP1-y samples are presented as a function of temperature, pressure and alloy composition. The threshold field and peak velocities measured across the alloy agreed with measurements made by Marsh, confirming that GalnAs is the most attractive composition for high speed microwave devices. Devices made from mid alloy material benefit from a low temperature sensitivity of the threshold current, which is less than half the sensitivity of GaAs devices. The results imply that alloy scattering remains influential even at high fields. In agreement with pressure measurements on InP and GaAs the threshold field increased with pressure primarily because of the increase in the electron effective mass. The experimental results are compared with Monte Carlo simulations for quaternary alloy compositions y=O, 0.5 and 1.0. The effect of alloy scattering on the high field measurements is discussed. High pressure studies on 1.3 and 1.55mum GalnAsP lasers were performed in order to investigate the cause of the high temperature sensitivity of the threshold current. Threshold current, spontaneous carrier lifetime and operating wavelength measurements versus pressure revealed that intervalence band absorption (IVBA) is the dominant loss mechanism at room temperature in the 1.55mum lasers. In 1.3mum lasers both IVBA and the CHHS Auger process are important processes at room temperature, the Auger process is probably the more dominant of the two. At room temperature neither carrier loss over the barrier nor the CHCC Auger process is dominant in 1.3mum or 1.55mum lasers. Carrier leakage from the active layer has been modelled theoretically using Monte Carlo simulation. Hot holes created via the CHHS Auger and IVBA processes are believed to be responsible for hole leakage to the n-InP confinement layer.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available
Keywords: Alloying semiconductors