Limits on the yield of photochemical solar energy conversion

摘要

Entropy and unavoidable irreversibility place a limit on the efficiency of photochemical solar energy conversion which is substantially lower than that placed by the first law of thermodynamics alone. Shockley and Queisserrsquo;s rsquo;rsquo;detailed balance limitrsquo;rsquo; on the efficiency ofphyphen;nhyphen;junction photovoltaic devices is a special case of this general thermodynamic limit on the efficiency of all quantumhyphen;utilizing solar energy converters. For a single photochemical system operating at 20thinsp;deg;C in sunlight not attenuated by the atmosphere, this efficiency cannot exceed 29percnt;. Under the same conditions, the efficiency of a solar converter composed of two photochemical systems can reach 41percnt;.