The inverted polymer solar cells using cuprous oxide as a hole transportation layer

Solution processed-metal oxide as an interlayer is introduced between the organic layer and the electrode for improving the performance of the low-cost inverted polymer solar cells. Our investigations indicate that cuprous oxide thin film as an electron blocking layer can modulate the Schottky barrier at organic/electrode interface and form an ohmic contact. Moreover, we also report the ridge structure zinc oxide as an electron selective layer in the inverted polymer solar cells. The cuprous oxide can function as a great hole transportation layer and the ridge structure zinc oxide can increase interfacial area for electron collection. The power conversion efficiency is improved from 3.34% to 4.02% by the introduction of the metal oxide interlayer. Compared to the vacuum technique, the fabrication of the metal oxide via solution process is simple and effective. The solution-based approach makes it attractive for application to mass production and potentially printed organic electronics.