English: Schematic of charge collection by solar cell electrodes. Light transmits through transparent conducting electrode, which is absorbed by the active layer. It creates electron hole pair, which are collected by both the electrodes. If charge carriers have to travel high distances compared to their diffusion length, their may be recombination losses on the way. The collected charge carriers in turn lead to current flow. Thus, active layer thickness, transparent electrode design and diffusion length determines solar cell performance.