Which mechanism limits the efficiency of dye-sensitized solar cells despite efficient molecular light absorption?

💡 Explanation

When excited by light, dye molecules inject electrons into the TiO2, but electron recombination occurs because surface defects act as trap states that capture electrons before they reach the collecting electrode, reducing overall charge collection. Therefore electron recombination at the TiO2 surface becomes limiting, rather than electrolyte decomposition, dye aggregation or quantum tunneling, which relate to different failure modes.

• Which consequence maximizes chiller efficiency at constant load?
• Which consequence results when isotopic enrichment increases deuterium concentration?
• Which risk increases when a chemical plant's cooling system delays quenching an exothermic reaction?
• Which outcome occurs when an endothermic reaction in a closed system reaches equilibrium, and temperature is increased?
• Which risk increases when light passes through birefringent material?
• Which effect occurs when a black hole's mass increases?