Characterization of doped GaInP nanowires for photovoltaics

Abstract: The interest in renewable energy sources has increased recently, which has resulted in increasing research in solar energy as an environmentally friendly way to obtain electricity due to a rising energy consumption and an arising environmental awareness. Direct harvesting of solar energy to electricity is called photovoltaics, where III-V semiconductors nanowires can be used to fabricate multijunction solar cells with promise to deliver high efficiency at low cost. The division of Solid State Physics at Lund University has been working during the last few years on a project for the fabrication of a tandem p-n junction solar cell. In this thesis project, doped nanowires of GaInP have been investigated and evaluated with optical and electrical measurements, with the aim to create high-bandgap p-n junctions. Electrical measurements show that both p- and n-doping can be achieved. Nanowires with p-i-n doping show excellent rectification with reasonably low ideality factors, and generate a clear photocurrent under illumination. Under forward bias, the p-i-n devices give yellow electroluminescence in agreement with photoluminescence experiments.