Semitransparent Plasmonic Photoconductor with Electron and Hole Transport Layers

Photodetectors, which convert light into electrical signals, are essential for image sensors and other optoelectronic devices. Plasmon-induced charge separation (PICS) offers an alternative method for photoelectric conversion to those based on semiconductor heterojunctions. In this study, we developed a new structure for a photoconductor based on PICS. In this structure, Au nanoparticles (AuNPs) are introduced to the interface between TiO 2 as an electron transport material and spiro-OMeTAD (Spiro) as a hole transport material. The TiO 2 |AuNP|Spiro photoconductor shows improved charge separation efficiency and enhanced photoresponses compared to TiO 2 |AuNP and AuNP|Spiro devices, likely due to suppressed recombination of energetic electrons and holes and improved carrier conductivity by the introduction of a hole transport material. This new approach to PICS-based photoconductors could lead to enhanced performance in various applications.