Inorganic semiconductor nanocrystals (NCs) with bright, stable, and wavelength-tunable luminescence are very promising emitters for various photonic and optoelectronic applications. Recently developed strategies for inorganic surface capping of colloidal NCs using metal chalcogenide complexes have opened new perspectives for their applications. Here we report an all-inorganic surface functionalization of highly luminescent IR-emitting PbS-CdS NCs and studies of their luminescence properties. We show that inorganic capping allows simple low-temperature encapsulation of inorganic NCs into a solution-cast IR-transparent amorphous As2S3 matrix. The resulting all-inorganic thin films feature stable IR luminescence in the telecommunication wavelength region. The high optical dielectric constant of As2S3 also helps reduce the dielectric screening of the radiating field inside the quantum dot, enabling fast radiative recombination in PbS-CdS NCs.