II-VI semiconductor epilayers grown by MBE on III-V semiconductor substrates

The MBE growth and characterization of undoped and In-doped, low resistivity Cd1-xZnxS (0<=x<=0.35) epilayers on (111) GaAs and of CdS on (110) InP are reported. Low resistivity (9x10-3 - 8x10-2 Ohm cm) Cd1-xZnxS layers have been obtained up to x = 0.20. Solar conversion efficiencies at AM2 of 1.5, 5.5 and 13% have been obtained for AR-uncoated CdS/GaAs, Cd1-xZnxS/GaAs and CdS/InP hetero-structures, respectively, showing that the lattice mismatch affects the electrical and photovoltaic behaviour of the hetero-junctions. The results suggest that MBE is a suitable technology for preparing low resistivity Cd1-xZnxS layers and high efficiency CdS/InP solar cells.