Inverted Organic Photodetectors With ZnO Electron-Collecting Buffer Layers and Polymer Bulk Heterojunction Active Layers

We report inverted-type organic photodetectors with zinc oxide (ZnO) electron-collecting buffer layers and polymer:fullerene bulk heterojunction active layers. A visible light was detected by the inverted organic photodetectors when a background UV light was ON, whereas no photocurrent signal was measured for visible lights without the background UV light. Interestingly, UV lights solely were successfully detected without any surrounding UV light. The present devices exhibited fast and stable photo-responses under modulated or continuous UV-visible lights.