CHALLENGES AND OPPORTUNITIES FOR PEROVSKITE SOLAR CELLS

摘要

Hybrid organic-inorganic solid state solar cells with perovskite-structured CH3NH3PM3 as active layer have recently been reported with over 20% efficiency, which emerges as the most promising candidate for the next generation solar cells. As a game changer in photovoltaics, perovskite type material exhibits striking excellence in both light absorption and charge transport (1069nm electron diffusion length and 1213 nm holes diffusion length). Despite its aura, the dark side of this rising star should not be ignored. Current grand challenges include the stability issue of CH3NH3PbI3, the use of environment-hazardous lead, the cost of complex organics as hole-blocking layer and the use of expensive noble metals as back cathode. On the other hand, opportunities are on the horizontal by fundamental understanding of the elementary processes of light absorption, charge separation and charge collection, which can provide valuable clues for designing better materials that overcome the drawback in current lead iodide based perovskite materials.