2012/04/05 by Emmanuel Lhuillier, Sean Keuleyan, Philippe Guyot-Sionnest +1 · 1 citation
Engineering · Materials Science · #Advanced Semiconductor Detectors and Materials #Chalcogenide Semiconductor Thin Films #Quantum Dots Synthesis And Properties
paper · doi:10.1088/0957-4484/23/17/175705
openalex publication_date 2012/04/05 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/30
Room temperature photodetection with HgTe colloidal quantum films is reported between 2 and 5 μm for particles of sizes between ~5 and ~12 nm diameter, and photodetection extends to 7 μm at 80 K. The size-tuning of the absorption of HgTe colloidal quantum dots, their optical cross section and the infrared absorption depth of films are measured. The tuning with radius is empirically given by [see formula in text] where R is in nm. The optical cross section of the colloidal dots at 415 nm is approximately proportional to their volume and given by σ(Hg)(415) = 2.6 ± 0.4 10(-17) cm(2)/mercury atom. The size-dependent optical cross section at the band edge ~1.5 10(-15) cm(2) is consistent with the expected oscillator strength of the quantum dots. The absorption depth of HgTe colloidal dot films is short, about 1-2 μm, which is an advantage for thin film devices. These properties agree rather well with the expectation from the k · p model. HgTe colloidal quantum dot thin films show a strong tuning with temperature with a large positive thermal shift between 0.4 and 0.2 meV K(-1), decreasing with decreasing size within the size range studied and this is attributed primarily to electron-phonon effects.