Radiation stability of CBD grown nanocrystalline CdS films against ion beam irradiation for solar cell applications

Here we investigate the effect of swift heavy ion irradiation (SHII) on various properties of chemical bath deposited nanocrystalline CdS (nCdS) thin films. For this purpose, nCdS films are exposed to the varying ion fluences (1 × 10¹¹–1 × 10¹⁴ ion/cm²) of 80 MeV O⁶⁺ ions. Glancing angle X-ray diffraction (GAXRD) and micro-Raman studies confirm almost negligible structural transformation in CdS after ion irradiation even at highest fluence i.e. 1 × 10¹⁴ ion/cm². GAXRD, micro-Raman spectroscopy, field emission scanning electron microscopy and UV–Visible absorption spectroscopy studies suggest that the structure, shape and size of the particles as well as band gap of the nCdS films remain unaltered upon irradiation. The quality of the films and their radiation hardness is investigated by optical as well as electrical properties using photoluminescence spectroscopy and Hall measurements respectively. The films are found to be radiation resistant for 80 MeV O⁶⁺ ion irradiation as compared to other heavy radiations. The stability of various properties of nCdS films under the impact of SHII may be due to lesser or comparable value of electronic energy loss (S_e) to the threshold value of S_e. Radiation hardness of nCdS thin films is a good sign for fabrication of high performance, radiation stable and long lasting solar cell for extraterrestrial applications.