An inverted bulk-heterojunction hybrid solar cell with the structure ITO/ZnO/P3HT:PbS/Au was prepared. The device performance was enhanced by inserting an interface buffer layer of CdSe quantum dots between the ZnO and the P3HT:PbS BHJ active layer.

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A systematic analysis of the data on swift heavy ion irradiation in semiconductors shows that the effects produced are determined not only by the electronic energy deposition but also by a number of other material characteristics. The study is carried out to highlight the role of film microstructure in determining the energy relaxation processes of heavy ions in semiconductors. To verify the idea, two sets of CdTe polycrystalline thin film samples, prepared using thermal evaporation and spray pyrolysis, which differ in their microstructure are irradiated with 100 MeV Ag7+ ions using a 15 UD Pelletron accelerator. Differences are noticed in the response of the two sets of films to the beam and are correlated with the differences in their microstructure. For the evaporated films defect annealing dominates at lower fluences, but at higher fluences the effects due to defect generation are dominant. An increase in the lattice constant with fluence due to an increase in the tensile strain is also observed in this case. For the spray deposited samples, however, defect generation always dominates and no change in the lattice parameter is observed. The optical band gap undergoes a red shift for both sets of films due to the introduction of band-tail states.

This study is carried out to verify the role of thin film microstructure in determining the energy relaxation processes of swift heavy ions in CdS polycrystalline thin films. Two sets of CdS thin film samples, differing in their microstructures, prepared using thermal evaporation and spray pyrolysis, are irradiated with 100 MeV Ag ions using Pelletron accelerator. It is observed that the effects produced differ significantly in the two films. For the evaporated films, defect annealing dominates for lower irradiation fluences but at higher fluences the effects due to defect creation and their migration are dominant. A transformation from the metastable cubic to hexagonal phase together with the creation of a significant amount of compressive strain is seen in these films for irradiation at the highest fluence. The optical absorption of the samples shows an increase in band gap from 2.34 eV for the as grown film to 2.43 eV for the sample irradiated at the highest fluence that is further confirmed by photoluminescence (PL) studies. In contrast, the spray deposited samples undergo a significant improvement of crystalline quality for all fluences as shown by an increase in x-ray diffraction peak intensity, sharper optical absorption edge, reduction in defect PL intensity, and removal of asymmetry in the line shape of the longitudinal optical phonon on its lower wavenumber side in Raman spectra.

Quantum dots (QDs) solids with iodide passivation are a key component for most of the well-performing PbS QDs solar cells.