with wavelengths from about 800 nm to about 1200 nm however for maximum enhancement in solar cell performance it may be necessary to balance between the photocurrent enhancements at the long wavelengths and the photocurrent suppression at the short wavelengths when tailoring the np size the electroless cell 100 a is prepared in an electroless deposition method 200 a which includes the following steps as shown in fig2 a immersing the raw cell in a metal ion solution which is also referred to as a bath with a selected concentration for a selected period of time both selected to control the particle size the shell thickness and the coverage density to deposit the particles 102 onto the cell 100 a step 204 a washing the coated cell 100 a step 206 a and the raw solar cell can be a commercially available textured mono or multicrystalline si solar cell the nps 102 can be formed of a noble metal e g ag or au and spherically or spheroidally shaped the photocurrent can be increased for sunlight with wavelengths from about 800 nm to about 1200 nm the electroless deposition method 200 a can be simple cost effective and scalable for large area device fabrication metal nanoparticles.