Giant Colloidal Quantum Dot/α-GaO Heterojunction for High Performance UV-Vis-IR Broadband Photodetector.

Broadband optoelectronics, which extend from the UV to IR regions, are crucial for imaging, autonomous driving, and object recognition. In particular, photon detection efficiency relies significantly on semiconductor properties, such as absorption coefficients and electron-hole pair generation rate, which can be optimized by designing a suitable p-n junction. In this study, we devise giant PbS colloidal quantum dots (G-PbS CQDs) that exhibit high absorption coefficients and broadband absorption.

Silver Telluride Colloidal Quantum Dot Solid for Fast Extended Shortwave Infrared Photodetector.

Extended shortwave infrared (eSWIR) photodetectors that employ solution-processable semiconductors have attracted attention for use in applications such as ranging, night vision, and gas detection. Colloidal quantum dots (CQDs) are promising materials with facile bandgap tunability across the visible-to-mid-infrared wavelengths. However, toxic elements, such as Hg and Pb, and the slow response time of CQD-based IR photodetectors, limit their commercial viability.

Reducing Domain Density Enhances Conversion Efficiency in GeTe.

Incorporating dilute doping and controlled synthesis provides a means to modulate the microstructure, defect density, and transport properties. Transmission electron microscopy (TEM) and geometric phase analysis (GPA) have revealed that hot-pressing can increase defect density, which redistributes strain and helps prevent unwanted Ge precipitates formation. An alloy of GeTe with a minute amount of indium added has shown remarkable TE properties compared to its undoped counterpart.

Colloidal InAs Quantum Dot-Based Infrared Optoelectronics Enabled by Universal Dual-Ligand Passivation.

Solution-processed low-bandgap semiconductors are crucial to next-generation infrared (IR) detection for various applications, such as autonomous driving, virtual reality, recognitions, and quantum communications. In particular, III-V group colloidal quantum dots (CQDs) are interesting as nontoxic bandgap-tunable materials and suitable for IR absorbers; however, the device performance is still lower than that of Pb-based devices. Herein, a universal surface-passivation method of InAs CQDs enabled by intermediate phase transfer (IPT), a preliminary process that exchanges native ligands with aromatic ligands on the CQD surface is presented.