GaLnAsP Solar Cells Grown by Hydride Vapor Phase Epitaxy for One-Sun Low-Concentration III-V/Si Photovoltaics

摘要

Dynamic hydride vapor phase epitaxy (D-HVPE) has recently reemerged as a low-cost alternative to metalorganic chemical vapor deposition (MOCVD) for the growth of highefficiency III-V solar cells. Quaternary GaInAsP solar cells in the bandgap range of ~1.6-1.8 eV are promising top-cell candidates for III-V/Si tandem solar cells. In this work, we report on the development of lattice-matched GaInAsP (Eg~1.66 eV) solar cells grown via low-cost HVPE at very high growth rates of ~0.7 μm/min (~42 μm/h). We demonstrate for the first time HVPE grown passivated GaInAsP homojunction solar cells that show substantial improvement in the short-wavelength photoresponse attributed to the incorporation of a GaInP window layer. The heterointerfaces in these multilayer devices were characterized by transmission electron microscopy. The best device achieved a certified one-sun efficiency of 18.7% under AM1.5G, demonstrating the viability of HVPE to grow multilayered structures comprising ternary and quaternary alloys. This work represents a promising step towards low-cost III-V/Si tandem photovoltaics with one-sun efficiencies exceeding 30%.