A particular advantage of using substantially crystalline particles of different metal compounds is that it removes the glass forming step from the process of manufacturing a conductive paste. The glass forming step typically has high energy demands, since it requires the glass precursors to be heated to temperatures above the melting point of the crystalline materials used to manufacture the glass. Glasses are typically used in conductive pastes due to their relatively low softening and melting points. Typically, glasses used in conductive pastes flow at temperatures in the range of about 400-700° C. The present inventors have surprisingly found that despite the considerably higher melting point of at least some of the substantially crystalline metal compounds used in the pastes of the present invention, these mixtures still exhibit similar flow and melt behaviour to glass frits, which enables them to be used with a similar firing profile and manufacturing method as pastes comprising glass frit.

As the skilled person will understand, avoiding the energy intensive glass forming step has advantages outside the field of conductive pastes for solar cells. The present inventors consider that their invention is applicable also to conductive pastes used to form conductive tracks and conductive coatings in other electronics applications, such as those mentioned herein.

The present inventors have also found that certain particle size distributions may have an advantageous effect. In particular they have observed that the behaviour of the pastes and fired electrodes tends to improve as particle size decreases.

Accordingly, in a second preferred aspect, the present invention provides a conductive paste for forming a conductive track or coating on a substrate, the paste comprising a solids portion dispersed in an organic medium,