The growth and study of Mn-doped US films on glass substrate using spray pyrolysis technique upto 15% of Mn doping level has been done. Structural changes from wurtzite to zinc blend is observed with increase in Mn concentration. Surface morphology of undoped films is found to possess self-assembled noodle-like alignment of grains, which dissociates on increasing Mn concentration. The photoconductivity measurements of these films in light are done in a homemade setup where light-emitting diode (LED) is used to illuminate the sample. In this setup usual complex arrangements needed for photoconductivity measurements are reduced to a great extent. The persistent photocurrent decays faster in Mn-doped CdS. (C) 2008 Elsevier B.V. All rights reserved.