Organic photovoltaic based on copper phthalocyanine with high open circuit voltage and significant current and voltage stability

Organic semiconductors are under investigation as a possible material to create low cost solar cells. We fabricated photovoltaic devices consisting of copper phthalocyanine (CuPc) modified with a sulfonated group /perylene-3, 4, 9, 10-tetracarboxylic dianhydride (PTCDA)/ bathocuproine (BCP) A large open circuit voltage (V$_{OC})$ of 0.74 V was recorded, superior to cells based on~ CuPc/PTCDA (V$_{OC}$ =0.55V). Our solar cells exhibits little change in their voltage and current for more than 7 months, superior to many organic solar cells which degrade significantly over days or weeks.