GaP/Si wire array solar cells

Abstract

Si wire arrays have recently demonstrated their potential as photovoltaic devices [1][2][3]. Using these arrays as a base, we consider a next generation, multijunction wire array architecture consisting of Si wire arrays with a conformal GaNxP1-x-yAsy coating. Optical absorption and device physics simulations provide insight into the design of such devices. In particular, the simulations show that much of the solar spectrum can be absorbed as the angle of illumination is varied and that an appropriate choice of coating thickness and composition will lead to current matching conditions and hence provide a realistic path to high efficiencies. We have previously demonstrated high fidelity, high aspect ratio Si wire arrays grown by vaporliquid-solid techniques, and we have now successfully grown conformal GaP coatings on these wires as a precursor to considering quaternary compound growth. Structural, optical, and electrical characterization of these GaP/Si wire array heterostructures, including x-ray diffraction, Hall measurements, and optical absorption of polymer-embedded wire arrays using an integrating sphere were performed. The GaP epilayers have high structural and electrical quality and the ability to absorb a significant amount of the solar spectrum, making them promising for future multijunction wire array solar cells.

Broadband absorption of semiconductor nanowire arrays for photovoltaic applications

“…Semiconductor nanowire solar cells are promising candidates for next-generation, thin-film photovoltaic devices due to their attractive anti-reflection and light-trapping properties. Recent experimental work has demonstrated verticallyaligned semiconductor nanowire arrays in silicon [1][2][3][4][5][6][7][8][9], germanium [10], various direct band gap materials [11][12][13][14][15][16][17][18], and combined systems [19][20][21].…”

Recent Advances in III–V Compounds/Polymer Hybrid Solar Cells

“…Absorption spectrum variation displayed in Figure 5b as well as reflectance and transmittance variation in the literature [ 150 ] show that the optimal filling ratio is determined only by the trade‐off between the reflection enhancement and transmission suppression with the increase in D/P. Furthermore, as shown in Figure 5c, photogeneration profiles in a quarter of the core‐shell NWA solar cells were investigated by coupled photoelectrical model (left) and conventional optical model based on Beer's absorption (right) [ 151,152 ] without optoelectrical coupling. It can be seen that the improved NWA structure can absorb 500 percent more photons per unit volume of material.…”