Efficient Photoelectrochemical Solar Cells Equipped with an n‐Si Electrode Modified with Colloidal Platinum Particles

Various platinum (Pt) colloid solutions were prepared and used for the modification of n‐type silicon (n‐Si) electrodes. All the photoelectrochemical (PEC) solar cells, equipped with the Pt‐colloid modified n‐Si electrodes thus prepared, gave the open‐circuit photovoltages of 0.550 to 0.630 V, much higher than those for n‐Si electrodes coated with continuous thin Pt layers, clearly showing the beneficial effect of the discontinuous metal coating. The PEC cells, equipped with the textured‐surface n‐Si electrodes modified with the Pt colloid particles prepared by Bredig's method, yielded an energy conversion efficiency of 14.9% in a three‐electrode configuration. The relation between the and the size and distribution of the Pt particles is discussed.