ABSTRACT
Successful heteroepitaxial growth and future issues in the metalorganic vapour phase epitaxy (MOVPE) of Cu-III-VI2 (III=A1,Ga and VI=S,Se) widegap chalcopyrite (Ch) semiconductors are briefly described. Careful optimization of the growth parameters enables observation of atomically smooth surfaces and predominant near-band-edge photoluminescence (PL) peaks from the c-axis (001)-oriented single-domain high-quality epilayers. All (001)-oriented Cu(Al,Ga)(S,Se)2 epilayers grown on GaAs (001) or GaP (001) substrates are shown to be biaxially tensile strained, due to the mismatch between the thermal expansion coefficients of the epilayers (α epi) and the substrates (α sub). A noticable excitonic feature is found in the PL spectra especially for CuAlS2 and CuGaS2 even at room temperature (RT). The potential of epilayers of Ch semiconductors as new short-wavelength light-emitting materials is demonstrated.
