Cd1-xMnxS nanoparticles (NPs) with size quantum confinement belong to the diluted magnetic semiconductor (DMS) quantum dot (QD) class of materials that has been widely studied in the last few years. The study of quasi-zero-dimensional Diluted Magnetic Semiconductors (DMS), such as Cd1-xMnxS Quantum Dots (QDs), is strongly motivated due to the localization of magnetic ions in the same places as the free-like electron and hole carriers occurring in these nanomaterials [1, 2]. This interesting phenomenon causes unique properties in DMS dots that can be explored in different technological applications, such as wavelength tunable lasers [3], solar cells [4, 5], or in spintronic devices [6, 7]. In this context, glass matrix-encapsulated Cd1-xMnxS NPs emerge as potential candidates for several applications, given that this host transparent material is robust and provides excellent stability for DMS nanostructures. Therefore, the luminescent properties and carrier dynamics of Cd1-xMnxS NPs should be comprehensively understood in order to target optical applications. For instance, different models based on rate equations can be employed to describe the temperature-dependent carrier dynamics of DMS nanostructures, such as they have been applied to semiconductor quantum wells [8], N-impurity complexes in III–V materials [9], and self-assembled semiconductor quantum dots [10].

It is well known that the optical properties of NPs can be significantly changed by interactions between nanostructures and their host material, due mainly to the formation of surface defects [11, 12]. These surface defects are heavily dependent on NP size and become more important with increasing surface–volume ratio. Generally, the comparison between the optical properties of Cd1-xMnxS QDs and their corresponding bulk is obtained in different environments. To the best of our knowledge, this study is probably the first that simultaneously investigates both the carrier dynamics and the magneto-optical properties of Cd1-xMnxS QDs and their corresponding bulk-like NC when both are embedded in the same host material.