Size dependence of optical properties in solution-grown Pb1-xFexS nanoparticle films

The optical band gap (E-g) of Pb1-xFexS solution-grown nanoparticle films was varied from 2.65 to 2.22 eV with an increase in iron concentration 0.25 less than or equal to x less than or equal to 0.75 in films grown at fixed pH and temperature by the chemical bath deposition method. The presence of excitonic structure in the ternary Pb1-xFexS for x greater than or equal to 0.50 suggests increasing binding energy with increase in iron concentration in the films. A shift of excitonic peak towards higher energy with an increase in iron concentration is also observed.