https://doi.org/10.1051/epjap/2020190216
Regular Article
Influences of thickness and temperature of low temperature GaAs buffer layer on two-step MOVPE grown GaAs/Ge heterostructures
1
Nanophotonics Research and Application Center, Department of Nanotechnology Engineering, Sivas Cumhuriyet University, 58140
Sivas, Turkey
2
East Anatolia High Technology Application and Research Center, Atatürk University, 25240 Erzurum, Turkey
3
Department of Physics Atatürk University, 25240 Erzurum, Turkey
* email: idemir@cumhuriyet.edu.tr
Received:
20
July
2019
Received in final form:
30
March
2020
Accepted:
13
May
2020
Published online: 26 June 2020
We investigate influence of GaAs buffer layer (BL) growth parameters such as temperature and thickness on the structural, morphological, crystalline and optical quality of metal organic vapor phase epitaxy (MOVPE) grown heterostructures of GaAs on Ge. It was found that the optimal BL conditions significantly decrease the effects of anti-phase boundaries (APBs) even when grown on offcut Ge substrate by two-step growth technique with AsH3 pre-flow to promote double atomic step formation. It is observed that as the growth temperature increases, the growth rate of the GaAs BL increases, too. Improvement on the structural quality is observed up to BLs temperature of 535 °C, then it decreases. On the other hand, as the different thick BLs, 12, 25, 75 nm are considered, the epilayer grown on the 25 nm thick BL has shown the lowest full width at half maximum (FWHM) value, large photoluminescence peak intensity and internal quantum efficiency (IQE).
© EDP Sciences, 2020
