An array of poly(methyl methacrylate-co-acrylic acid) nanospheres of various sizes (i.e., average size of 101 nm) with excellent thermal stability has been successfully synthesized via emulsion polymerization technique. The thermal properties of such materials in addition to the optical property of the metal nanoparticles have been carefully characterized. The integration of the nanospheres onto a photovoltaic cell has effectuated an increment of the power conversion efficiency from 2 to 3.14% (i.e., a relative enhancement of 57%). A further enhancement of the electrical characteristics has been observed if gold nanoparticles have been encapsulated by the polymeric nanospheres. The power conversion efficiency of the PV cell incorporated with gold nanoparticles of 3.75 x 10(-3) wt% has attained 5.32% (i.e., a relative enhancement of 166%). This may be attributed to the localized surface plasmon effect as a strong absorption peak of the gold nanoparticles has been detected at the wavelength of 525 nm. A comparison of electrical characteristics conducted between nanospheres which have been encapsulated with silver and gold nanoparticles indicates the fact that both noble metals have yielded a momentous enhancement of the power conversion efficiency. Consequently, this novel technique utilizing nanospheres which have been encapsulated with noble metals (i.e., Ag and Au) is assuredly paving a way toward high-efficiency photovoltaic cell.