Solution Processed Quantum Dot Devices for Signal Amplification

Colloidal quantum dots (CQDs) offer a tunable and solution‐processable platform for optoelectronic devices. However, simultaneous optimization of multiple functionalities such as electrical gain and photodetection in the same device is challenging due to conflicting material requirements. While photodetection based on CQDs has advanced greatly, demonstrations of purely electrical gain are rare. Here, we report a gain‐only device based on PbS CQDs, designed to isolate electrical amplification functionality. PbS CQDs were synthesized using standard methods and modified with Al 2 O 3 additives. Transmission electron microscopy confirms high crystallinity and uniform dispersion. Devices fabricated by spin‐coating exhibited strong electrical gain, with maximum amplification of 53 dB at a forward bias of 1.25 V. This architecture demonstrates the potential for standalone signal amplification in CQD systems and paves the way for integration with optimized photodetector devices.