Advancing Fab-Compatible Color-Selective Organic Photodiodes: Tailored Molecular Design and Nanointerlayers
Won Jun Pyo, Gyuri Kim, Sinwon Kim, H. Oh, Dongki Keum, B. G. Kim, Dowan Kim, Chan So, Sang‐Jun Lee, Dong‐Woo Jee, In Hwan Jung, Dae Sung Chung
Abstract
High-performance organic photodiodes (OPDs) and OPD-based image sensors are primarily realized using solution processes based on various additives and coating methods. However, vacuum-processed OPDs, which are more compatible with large-scale production, have received little attention, thereby hindering their integration into advanced systems. This study introduces innovations in the material and device structures to prepare superior vacuum-processed OPDs for commercial applications. A series of vacuum-processable, low-cost p -type semiconductors is developed by introducing an electron-rich cyclopentadithiophene core containing various electron-accepting moieties to fine-tune the energy levels without any significant structural or molecular weight changes. An additional nanointerlayer strategy is used to control the crystalline orientation of the upper-deposited photoactive layer, compensating for device performance reduction in inverted, top-illuminated OPDs. These approaches yielded an external quantum efficiency of 70% and a specific detectivity of 2.0 × 10 12 Jones in the inverted structures, which are vital for commercial applications. These OPDs enabled visible-light communications with extremely low bit error rates and successful X-ray image capture.