The Polymer Society of Korea

Abstract

Solution-processed shortwave infrared (SWIR) photodetectors have emerged as essential components for diverse applications, ranging from autonomous platforms to quantum information systems. For these technologies, achieving simultaneously high gain and broad bandwidth at the telecommunications wavelength of 1550 nm—comparable to state-of-the-art commercial InGaAs devices—remains a critical challenge. In this work, we introduce a generalized approach to boost gain in photodiode architectures through carrier multiplication. Our method leverages heterogeneous colloidal quantum dot (CQD) solids, processed from solution, to engineer the spatial distribution of the internal electric field within the active layer. By exploiting quantum confinement effects, we realize a localized field enhancement that promotes efficient carrier multiplication. The resulting CQD-based photodetectors deliver an exceptional gain–bandwidth product, representing the highest value reported to date for solution-processed infrared photodetectors.