NOVELTY - A heterojunction photovoltaic device (D1) comprises: a substrate having a light incident surface and a backside surface and containing at least one photovoltaic absorber; a dielectric barrier layer positioned over the transparent conducting oxide layer; at least one via present in the dielectric barrier layer that terminates at a location in the device; and an electrical contact that is electrically connected to the transparent conducting oxide layer, where the electrical contact comprises a base formed in the via and a cap projecting above the dielectric barrier layer.    USE - As heterojunction photovoltaic device (claimed) such as chalcogenide-based solar cells.    ADVANTAGE - The heterojunction photovoltaic device facilitates ease of making external electrical connections; provides improved adhesion that provides enhanced moisture resistance. The heterojunction photovoltaic device provides strategies for improving the adhesion among at least two of transparent conducting oxides, electrically conductive grid materials, and dielectric barrier layers; is more resistant to delamination, rupture, and moisture intrusion; and also has enhanced service life.    DETAILED DESCRIPTION - A heterojunction photovoltaic device (D1), comprises: a substrate having a light incident surface and a backside surface and containing at least one photovoltaic absorber, where the substrate includes at least one transparent conducting oxide layer interposed between the absorber and the light incident surface; a dielectric barrier layer positioned over the transparent conducting oxide layer; at least one via present in the dielectric barrier layer that terminates at a location in the device such that the via provides open communication to the transparent conducting oxide layer through the dielectric barrier layer without penetrating all the way through the transparent conducting oxide layer; and an electrical contact that is electrically connected to the transparent conducting oxide layer, where the electrical contact comprises a base formed in the via and a cap projecting above the dielectric barrier layer. An INDEPENDENT CLAIM is included for making (M1) the photovoltaic device, involving (a) providing a substrate having a light incident surface and a backside surface and comprising at least one photovoltaic absorber, where the substrate includes at least one transparent conducting oxide layer interposed between the absorber and the light incident surface; (b) causing a dielectric barrier layer to be positioned over the transparent conducting oxide layer; (c) causing at least one via to be present in the dielectric barrier layer that terminates at a location in the device such that the via provides open communication to the transparent conducting oxide layer through the dielectric barrier layer without penetrating all the way through the transparent conducting oxide layer; and (d) forming an electrical contact that is electrically connected to the transparent conducting oxide layer, where the electrical contact comprises a base formed in the via and a cap projecting above the dielectric barrier layer.