Temperature- and Size-Dependent Photoluminescence of CuInS2 Quantum Dots

Abstract

We present the results of a temperature-dependent photoluminescence (PL) spectroscopy study on CuInS2 quantum dots (QDs). In order to elucidate the influence of QD size on PL temperature dependence, size-selective precipitation was used to obtain several nanoparticle fractions. Additionally, the nanoparticles’ morphology and chemical composition were studied using transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The obtained QDs showed luminescence in the visible–near infrared range. The PL energy, linewidth, and intensity were studied within an 11–300 K interval. For all fractions, a temperature decrease led to a shift in the emission maximum to higher energies and pronounced growth of the PL intensity down to 75–100 K. It was found that for large particle fractions, the PL intensity started to decrease, with temperature decreasing below 75 K, while the PL intensity of small nanoparticles remained stable.

Alteration of the Optoelectronic Properties of CuInS2 Quantum Dots via Colloidal Annealing

“…The resulting fits are shown in Figure S2 . The longer wavelength (lower energy) emission is related to a defect emission (DE) in the QDs. , The shorter wavelength (higher energy) peak position is associated with band edge emission (BE). The peak position of the BE feature only fluctuates by ∼7 nm for a colloidal annealing time ranging from 5 to 90 min, indicating additional particle growth during annealing is negligible.…”