NOVELTY - Enhanced infrared (IR) light absorbing photovoltaic stack comprises a top electrode; an absorbing layer (AL) comprising light-absorbing semiconductor nanoparticles (SNPs) that absorb at least a portion of the infrared spectrum, and at least one plasmonic nanoparticle (PNP); and a bottom electrode. The PNP scatters incident IR light and thus enhances IR absorption by the SNPs.    USE - The photovoltaic stack is useful for generating electricity or converting light into electricity (claimed).    ADVANTAGE - The plasmonic nanoparticles and colloidal quantum dots have enhanced photovoltaic conversion efficiencies.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for:    (1) a photovoltaic device comprising the photovoltaic stack, or comprising more than one photovoltaic stack;    (2) a composition comprising: infrared absorbing SNPs and at least one PNP; where the composition contacts an electrode;    (3) an enhanced absorbing medium (EAM) comprising SNPs embedded with at least one PNP; where the SNPs comprises infrared absorbing lead sulfide (PbS) quantum dots; and where the PNP comprises: a spherical dielectric core having an average diameter of about 25 nm to about 100 nm; a metal shell surrounding the core and having an average thickness of about 2 nm to 50 nm; and optionally an insulating shell surrounding the metal shell;    (4) a light emitting colloid comprising colloidal SNPs and at least one PNP; where the SNPs comprises infrared absorbing PbS quantum dots; and where the PNP comprises: a spherical dielectric core having an average diameter of about 25 nm to about 100 nm; a metal shell surrounding the core and having an average thickness of about 2 nm to 50 nm; and, optionally an insulating shell surrounding the metal shell;    (5) a method of preparing the photovoltaic which involves providing a bottom electrode selected from fluorine-doped tin oxide (FTO), indium-tin-oxide (ITO), titanium dioxide (TiO2)-FTO, zinc oxide (ZnO)-TiO2-FTO, TiO2-ITO, and ZnO-TiO2-ITO; drop-casting SNPs to form a first AL on the bottom electrode; drop-casting at least one PNP onto the AL; drop-casting SNPs onto the at least one PNP and first AL to form a second AL; and depositing a top electrode onto the second AL; thus preparing the photovoltaic; and    (6) a method of generating electricity or converting light into electricity, which involves illuminating the photovoltaic or composition with infrared light.