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The effect of selenium‐free annealing on cesium fluoride (CsF)‐treated Cu(In,Ga)Se2 (CIGS) thin films is investigated and their solar cell performance is evaluated. Annealing of CsF‐treated CIGS thin films changes the surface morphology and the chemical composition, and reduces the Urbach energy. However, the full benefit of the reduced Urbach energies of the annealed samples is not obtained, because of an increased buffer/CIGS interface recombination as a consequence of re‐evaporation of the alkali‐containing layer from the surface region upon annealing. On the other hand, CsF‐treated CIGS thin films without any annealing after the post‐deposition treatment (PDT) preserve the alkali‐containing layer at the surface, thereby leading to an improved buffer/CIGS interface. Consequently, the open‐circuit voltage (V OC) and fill factor improve significantly in these devices. The Urbach energies of both annealed and nonannealed solar cells are calculated from external quantum efficiency measurement to understand their impact on V OC and V OC deficit. No correlation between the V OC deficit and the Urbach energies is observed.

The fabrication of Sb2Se3 thin-film solar cells deposited by a pulsed hybrid reactive magnetron sputtering (PHRMS) was proposed and examined for different growth conditions. The influence of growth temperature and Se pulse period were studied in terms of morphology, crystal structure, and composition. The Sb2Se3 growth showed to be dependent on the growth temperature, with a larger crystal size for growth at 270 °C. By controlling the Se pulse period, the crystal structure and crystal size could be modified as a function of the supplied Se amount. The solar cell performance for Sb2Se3 absorbers deposited at various temperatures, Se pulse periods and thicknesses were assessed through current-voltage characteristics. A power conversion efficiency (PCE) of 3.7% was achieved for a Sb2Se3 solar cell with 900 nm thickness, Sb2Se3 deposited at 270 °C and Se pulses with 0.1 s duration and period of 0.5 s. Finally, annealing the complete solar cell at 100 °C led to a further improvement of the Voc, leading to a PCE of 3.8%, slightly higher than the best reported Sb2Se3 solar cell prepared by sputtering without post-selenization.

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