Room-temperature, mid-infrared photodetection in colloidal quantum dot/conjugated polymer hybrid nanocomposites: a new approach to quantum dot infrared photodetectors

A unique and distinct approach to unipolar, intraband transitions appropriate for room-temperature, mid- and long-wave-infrared (IR) photodetection is to use active regions comprising colloidal quantum dots (CQDs) synthesized by inorganic chemistry embedded in conjugated polymers. The polymer not only enhances quantum confinement of and electron localization in CQDs, but it also assists in the conduction of electrons photogenerated by the absorption of IR light. Preliminary demonstrations of intraband, mid-wave IR absorption and Fourier transform IR (FTIR) spectral response at room temperature in CdSe/MEH-CN-PPV hybrid nanocomposite thin films are promising, yet the inherent lack of control over hybrid nanocomposite morphology due to solution-based deposition is an inherent challenge. Matrix-assisted pulsed laser evaporation is a vacuum-based deposition technique that could address this challenge by providing more homogeneous distributions of CQDs in hybrid nanocomposite thin films.