Speakers - 2026

Title: Enhanced performance quantum dot infrared photodetectors via interface engineering with mxenes

Abstract

Infrared photodetectors are crucial for a range of applications, including night vision, optical communication, and environmental monitoring. However, their effectiveness is often hindered by poor charge transport and interfacial losses in quantum dot-based designs. MXenes, known for their high metallic conductivity, adjustable surface terminations, and excellent optical transparency, present a unique opportunity to improve these interfaces for better optoelectronic performance. In this work, Ti3C2Tx MXene as functional layer via interface engineering for PbS quantum dot infrared photodetectors are systematically investigated, where it functions as an electrode, transport layer, and interfacial modifier, respectively. The high-quality of the as-synthesized materials, interfaces and favorable energy alignment are confirmed by the extensive structural, optical, and electronic analyses. As result, a responsivity of 1032.37 A/W with a specific detectivity of 4.56 × 1013 Jones and external quantum efficiency of 1.311×105 % is obtained from photodetector ITO/ZnO/Ti3C2Tx/PbS/MoO3/Ti3C2Tx under 1 µWcm-2 980 nm illumination. Our Finite difference time-domain (FDTD) simulations further confirm our experimental results, indicating that dual MXene incorporation significantly enhances optical field confinement and absorption within the PbS layer. Thus, it illustrates that MXene-enabled interface engineering and optical coupling can establish a new design paradigm for high-performance, solution-processed infrared photodetectors, effectively bridging the gap between quantum materials and practical optoelectronics.