Solar cell contact structures formed from metal paste and methods of forming solar cell contact structures from metal paste are described. In a first example, a solar cell includes a substrate. A semiconductor region is disposed in or above the substrate. A contact structure is disposed on the semiconductor region and includes a conductive layer in contact with the semiconductor region. The conductive layer includes a matrix binder having aluminum/silicon (Al/Si) particles and an inert filler material dispersed therein. In a second example, a solar cell includes a substrate. A semiconductor region is disposed in or above the substrate. A contact structure is disposed on the semiconductor region and includes a conductive layer in contact with the semiconductor region. The conductive layer includes an agent for increasing a hydrophobic characteristic of the conductive layer.