“…However, the main problem encountered for III-V element-based solar cells mainly lies in the development of large surface photovoltaic structures due to their high cost, making the employment of low cost substrates highly desirable. Accordingly, the epitaxial growth of the GaAs layer on Si substrate has attracted considerable attention owing to their large area availability, low cost and high mechanical strength [ 9 , 10 , 11 , 12 , 13 , 14 ]. Promising InAs/GaAs QD-based optoelectronic devices, directly grown on Si substrate, have already been reported [ 15 , 16 , 17 , 18 , 19 , 20 ].…”