The Effect of Au Nanoparticles on the Photovoltaic Conversion Efficiency in CdTe/CdS Thin Films

In our last study, we have worked on the effects Ag and Au nanoparticles have on the efficiency of CdS/CdTe thin film solar cells. Both had a positive effect on the efficiency of photovoltaic conversion. Now, we are testing Au nanoparticles on the same cells and plan on comparing the effects of different deposition times, and laser energy on the Au, and how it effects efficiency and Au nanoparticle size. We used PLD (pulsed laser deposition) to create these cells. The laser shoots the target material we want to deposit (CdS,Au,CdTe) turning it into plasma plume that deposits onto ITO (indium tin oxide) coated glass. Varying how long the laser shoots at the Au and at what energy changes the amount of Au deposited and the size and distribution of the particles as well. The more Au in the np junction, the more the increase in the efficiency of the solar cell due to plasmonic resonance effects. However, the efficiency cuts off with after a threshold value for Au deposition. Our last study concluded that we had already passed this saturation point, so now, we are testing lower deposition lengths and energies. The Au embedded cells were characterized by XRD, AFM, SEM/EDX, and a sourcemeter setup.