Selectively-grown InGaP/GaAs on silicon heterostructures for application to photovoltaic-photoelectrolysis cells

Photovoltaic-photoelectrochemical (PV-PEC) cells based ion InGaP/GaAs show excellent prospects for efficient production of hydrogen by electrolysis of water using solar energy. We describe a combined close-spaced vapor transp ort (CSVT)/liquid-phase epitaxy (LPE) process co produce arrays of selectiv ely-grown mesas of InGaP/GaAs on silicon substrates. Unlike other semicondu ctor devices, the PV-PEC cell is well suited for such selectively-grown, di scontinuous heteroepitaxial films. Thus, this device application affords ex ploiting the potential advantages of selective epitaxy, namely, the substan tial reduction of stress and defects caused by thermal expansion and lattic e mismatch between the silicon substrate and III-V epilayers, (C) 2001 Publ ished by Elsevier Science B.V.