Synthesis, characterization and photovoltaic studies of CuInS₂ nanostructures

In this investigation, (1,8-diamino-3,6-dioxaoctan)copper(II)sulfate, ([Cu(DADO)]SO₄), bis(propylenediamine)copper(II)sulfate, and ([Cu(pn)₂]SO₄) were applied as copper precursors to fabricate CuInS₂ (CIS) nanostructures in presence of microwave irradiation. Besides the effect of copper precursor, the effect of microwave power and time of irradiation on morphology of CuInS₂ nanostructures were investigated. The as-prepared products were analyzed by XRD, PL, FT-IR, EDS, and SEM. The results of XRD patterns were indicated that pure CuInS₂ with tetragonal phase could be only obtained after annealing at 400 °C for 2 h in a mixture of 85 % Ar and 15 % H₂ gases. SEM images were shown that regular hierarchical nanostructures of CuInS₂ were obtained with the aid of [Cu(pn)₂]SO₄ as copper precursor under 900 W irradiation power for 12 min. The photovoltaic behaviors of as-synthesized CuInS₂ nanostructures were studied after deposition of CdS film on chemical bath. CuInS₂ film was directly deposited on the surface of the CdS film through doctor blade method. The as-deposited CdS/CuInS₂ films were applied in photovoltaic measurements.