Efficient broad-spectrum parallel tandem organic solar cells based on the highly crystalline chloroaluminum phthalocyanine films as the planar layer

Abstract

Efficient parallel tandem organic solar cells are demonstrated by using the highly crystalline chloroaluminum phthalocyanine (AlClPc) films as the planar layer. Their broad photoresponse from 400–900 nm is contributed to the strong near-infrared absorption of the AlClPc films and the good complementarity between AlClPc and zinc phthalocyanine. Importantly, the high external quantum efficiency is obtained in the entire response range with the peak value 65% due to the high carrier mobility of the AlClPc films, and correspondingly the high power conversion efficiency of 3.5% is attributed to the large short circuit current density of 12.15 mA/cm2.