Siloxane Molecular Glue for Ultrarobust Interface Engineering in High‐Performance Colloidal Quantum Dot Infrared Image Sensors

Abstract

ABSTRACT Interfacial defects and poor mechanical robustness critically limit the performance of colloidal quantum dot (CQD) photodiodes for infrared imaging. Here, we introduce a bifunctional organosilane, (3‐mercaptopropyl) methyldimethoxysilane (MDMS), as an interfacial layer to simultaneously address these challenges in inverted PbS CQD photodiodes. MDMS molecules form robust covalent bridging at the CQDs/electron transport layer (ETL) interface through thiol‐based coordination and hydrolysis‐condensation into a cross‐linked siloxane network. This interface engineering not only reinforces mechanical adhesion (achieving 5B rating in ASTM D3359 tests vs. 0B/1B for C 60 controls) but also provides an ideal nucleation surface for ALD‐grown SnO 2 ETL, suppressing island‐like growth and interfacial defects. The optimized devices deliver a specific detectivity of 2.37×10 12 Jones at 1550 nm under 0 V while maintaining 79% EQE under −0.1 V, with dark current reduced by >50% compared to C 60 ‐based controls. Monolithic integration with a silicon ROIC yields a SWIR imager with outstanding photoresponse non‐uniformity (2.8%) and spatial resolution (26 lp/mm at 50% MTF), demonstrating silicon wafer perspectivity and material discrimination. This work provides an efficient strategy for addressing interfacial issues in CQD optoelectronics.