Versatile nonplanar perylene diimide-based acceptor for inverted organic solar cells and photodetectors with modified ZnO buffer layers

The versatile nonfullerene perylene diimide-based electron acceptor was applied for inverted organic solar cells and organic photodetectors with good device performance. The ZnO films were modified by ethylene glycol (EG), ethanedithiol (EDT) and propanediol (PDO) as electron transporting layers. The energy levels of ZnO buffer layers were tuned to facilitate charge injection between the electrodes and the active layers. The ideal miscibility and interpenetrated network of subsequently deposited active layer was achieved on EG modified ZnO interlayer. Compared to the conventional device, the efficiency of the inverted device using ZnO/EG as electron transporting layer was improved to 3.61%, with a higher Jsc of 10.06 mA/cm2. The dark current of the organic photodetector could be dramatically reduced by the interfacial modification. The ZnO/EG based OPD exhibited low dark current of 3.24 x 10-9A/cm2 at -0.1 V and external quantum efficiency (EQE) of 48.6% at 700 nm, with a responsivity (R) of 0.274 A/W and a specific detectivity (D*) of 8.52 x 1012Jones.

Automated summary

The versatile nonfullerene perylene diimide-based electron acceptor showed good device performance in inverted organic solar cells and organic photodetectors. The ZnO films were modified with different materials to enhance electron transportation. The efficiency of the inverted device using ZnO/EG as the electron transporting layer was improved to 3.61%, with a higher Jsc of 10.06 mA/cm2. The interfacial modification also reduced the dark current of the organic photodetector and improved its external quantum efficiency.