https://vital.seals.ac.za/vital/access/manager/Index en-us 5 https://vital.seals.ac.za/vital/access/manager/Repository/vital:26423 Thu 13 May 2021 08:53:16 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:10559 Thu 13 May 2021 07:18:21 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:26433 0.3. The possibility that Si could become a DX-centre in AlxGa1-xN was then investigated. However, Hall effect measurements showed that the Si activation energy increased in good agreement with the model of a shallow effective mass state donor, with no sudden increase in ED being observed up to x = 0.4. It was then suggested that the increase in the E1 and E2 activation energies, as well as the exciton localisation energies, could be due to the 9 7 valence band crossover, which occurs at roughly the same composition. However, due to the scarcity of reports on the valence band structure in AlxGa1-xN no conclusions could be made at this stage as to the effect of the 9 7 valence band crossover on the PL properties of AlxGa1-xN.]]> Thu 13 May 2021 05:42:11 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:10518 Thu 13 May 2021 00:39:09 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:10537 580 ˚C) growth temperatures reduce the Mg incorporation. High VI/II ratios also decrease the Mg incorporation, as evidenced by the red-shift of the donor bound exciton (D°X) line. This is ascribed to a stronger premature reaction between (MeCp)2Mg and the oxidant or a preferential heterogeneous interaction between the Mg and oxygen species on the growth front. For both oxidizing agents (O2 and TBOH), the growth at 420 ˚C and a VI-II ratio of 60 on c-Al2O3 gave optimal quality layers in terms of their optical and structural quality. A comparison of films grown using TBOH and O2 gas as oxidizing agent shows no major difference in terms of Mg incorporation. The effect of annealing, the inclusion of a buffer layer and the influence of growth rate on the properties MgxZn1-xO thin films are also reported.]]> Thu 13 May 2021 00:01:15 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:73676 Fri 28 Jun 2024 14:39:11 SAST ]]>