A method of making a vacuum insulating panel including a first substrate, a second substrate, a plurality of spacers provided in a gap between at least the first and second substrates, and a seal provided between at least the first and second substrates, the seal comprising a first seal layer, and optionally second and/or third primer layer(s). The method may include at least one of: (i) laser heating, using a laser beam from a laser, the first seal material for firing and/or sintering the first seal material to form the first seal layer, in a manner that causes TeO.sub.4>TeO.sub.3 in the first seal material to transform into TeO.sub.3>TeO.sub.4 due to said laser heating, whereby an amount of TeO.sub.4 decreases and an amount of TeO.sub.3 increases due to said laser heating, and/or (ii) laser heating in a manner that causes V.sub.2O.sub.5>VO.sub.2 in the first seal material to transform into VO.sub.2>V.sub.2O.sub.5 due to said laser heating whereby an amount of VO.sub.2 increases and an amount of V.sub.2O.sub.5 decreases due to said laser heating, so that after said laser heating the first seal layer comprises more VO.sub.2 than V.sub.2O.sub.5 by wt. %.

The present disclosure generally relates to a fire-through aluminium paste composition to selectively fire through a passivation layer, and fired compositions thereof. In particular, the fire-through aluminium paste composition of the present disclosure comprises an aluminium component and a glass component, wherein the glass component comprises at least two glass frits. The present disclosure also relates to a processes for preparing a fire-through aluminium paste composition, and its use in the manufacture of a bifacial PERC solar cell.