The fabrication of GaInP and InGaAs quantum well solar cells (QWSC)

In this thesis, the GaInP and InGaAs quantum well solar cell (QWSC) structures were grown on GaAs substrates using Molecular Beam Epitaxy (MBE) technique. The growth QWSC structures were cut into several pieces and some of these were annealed at different temperatures under nitrogen (N2) flow using rapid thermal annealing (RTA) system. The structural properties of the annealed and non-annealed structures were investigated using high resolution x-ray diffraction (HRXRD). The formed dislocations as a result of annealing were attributed to the different properties of samples such as growth conditions, thicknesses and indium concentrations. After the QWSC fabrication, the forward bias dark and under AM1.5G standart illumination current-voltage (I-V) measurements that is important for the solar cells were carried out. As a result of I-V measurements, the short circuit currents (Isc), open circuit voltages (Voc), fill factors (FF), energy conversion efficiencies (?) of GaInP and InGaAs QWSCs were found. The efficiencies was observed as 0,16 and 0,15 after annealing, while it was 0,14 before annealing and the thermal annealing process was discussed to increase the SC efficiency.