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CuInSe2 films with Cu/In ratios of m=0.83–0.99 have been deposited on glass substrates by the co-evaporation method using a bi-layer process. The effects of sodium in these films have been investigated by comparing the electrical and optical properties of the films with and without the Na2Se incorporation. Two donor-acceptor pair emissions, [D, A]α at 0.89–0.94 eV and [D, A]β at 0.84–0.87 eV, were typically observed in the photoluminescence spectra. The relative intensity of [D, A]α to [D, A]β was found to depend strongly on both the Cu/In ratio and Na incorporation. For the films with m=0.94, [D, A]α was predominantly observed regardless of Na incorporation. For m≤0.90, [D, A]β became dominant for the films without Na, while [D, A]α remained as the dominant emission for the films with Na. A correlation between the prominence of [D, A]α and resistivities below 2×103 Ω· cm was found, suggesting a reduced compensation by suppressed Se vacancy donors due to the presence of Na.

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CuIn3Se5 films have been deposited with Na2S on Coning 7059 glass substrates by the two-stage co-evaporation method. Stoichiometric CuIn3Se5 films with p-type conduction with the resistivities of 106 Ω·cm range were obtained by our sodium control technique. Enhanced grain growth and preferred (112) orientation were also clearly observed with sodium incorporation; the same effect that has been reported for chalcopyrite CuInSe2 thin films. The effects of sodium in these films have been investigated by comparing the electrical and optical properties of CuIn3Se5 films with and without the Na incorporation. A correlation between the photoluminescence spectra and the resistivity or conduction type of the CuIn3Se5 films was found, suggesting a reduction in compensation due to the suppression of donor-type defects by the presence of Na.

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A ZnSe-ZnTe strained-layer superlattice (SLS) was grown on an InP substrate by molecular beam epitaxy for the first time. The x-ray diffraction measurement technique was used to confirm the existence of the high quality SLS structure. Overall quality may also be inferred from the observed quantum size effects of the photoluminescence data.