NOVELTY - Photovoltaic device (D1) (30) for converting light to electrical energy where (a) primary light absorbing component, comprising multi band gap n-copper indium selenide (n-CIS) compounds including indium-rich (Cu2Se) (In2Se3)n+1) group of semiconductors (I) is combined with (b) mid-gap component(s), having band gap wider than n-CIS absorber, and comprising semiconductor compounds including IB-VII-VIx, 1B-IIA-VI-VII, metal halides, chalcogenides and oxides, and (c) a wide-gap conducting window component, comprising at least one material e.g. arylamine and aromatic polyamine, is claimed.    USE - The photovoltaic device is useful for converting light to electrical energy (claimed).    ADVANTAGE - The photovoltaic device is highly efficiency, stable, low cost solar energy converter for electric power generation.    DETAILED DESCRIPTION - Photovoltaic device (D1) for converting light to electrical energy where (a) the primary light absorbing component, comprising multi band gap n-copper indium selenide (n-CIS) compounds including indium-rich (Cu2Se) (In2Se3)n+1) group of semiconductors of formula (I) is combined with (b) mid-gap component(s), having band gap wider than the n-CIS absorber, and comprising semiconductor compounds including IB-VII-VIx, 1B-IIA-VI-VII, metal halides, chalcogenides and oxides, and (c) a wide-gap conducting window component, comprising at least one material including arylamine and aromatic polyamine, naphthalocyanine and their derivatives, doped fullerene, functionalized fullerene and fullerene derivatives, magnesium phthalocyanine, rubrenes and oxadiazole, conjugated polymers including poly(aniline) and its derivatives, polypyrrole and its derivatives and/or their blends, and halides, pseudo-halides, oxides or chalcogenides of IB, IIB and III metals, or oxides or chalcogenides of IB-III alloys, is claimed.    n = greater than 0    INDEPENDENT CLAIMS are also included for:    (1) a photovoltaic device (D2) comprising: a n-CIS absorber component including (I), the mid-gap component comprising at least one material including selenium, copper(I) oxide, gallium selenide, copper indium selenide iodide (CuIn2Se3I), cadmium selenide and indium(III) selenide, and the wide-gap window component comprising the semiconducting material and silver iodide, copper(I) oxide, gallium selenide, gallium sulfur, zinc tin oxide (ZnSnO2) copper gallium oxide, copper aluminum oxide, copper indium oxide, copper aluminum selenide, copper aluminum sulfide, silver gallium sulfide and barium copper sulfide; and    (2) fabricating the photovoltaic device, comprising: depositing the primary light absorbing n-CIS component, adding the mid-gap component; and (c) depositing the wide-gap window component.    DESCRIPTION OF DRAWING(S) - The figure shows a solar cell where the active components comprise n-CIS, mid-gap intermediary layer and p-type window.    Solar cell battery (20)    Anode (21)    Cathode (22)    Solar cell device (30)    Intermediate layer (31)