Comparison of the thermal decomposition processes of several aminoalcohol-based ZnO inks with one containing ethanolamine

Abstract

Four inks for the production of ZnO semiconducting films have been prepared with zinc acetate dihy-drate as precursor salt and one among the following aminoalcohols: aminopropanol (APr), aminomethylbutanol (AMB), aminophenol (APh) and aminobenzyl alcohol (AB) as stabilizing agent. Their thermaldecomposition process has been analyzed in situ by thermogravimetric analysis (TGA), differential scan-ning calorimetry (DSC) and evolved gas analysis (EGA), whereas the solid product has been analysedex-situ by X-ray diffraction (XRD) and infrared spectroscopy (IR). Although, except for the APh ink, crys-talline ZnO is already obtained at 300◦C, the films contain an organic residue that evolves at highertemperature in the form of a large variety of nitrogen-containing cyclic compounds. The results indicatethat APr can be a better stabilizing agent than ethanolamine (EA). It gives larger ZnO crystal sizes withsimilar carbon content. However, a common drawback of all the amino stabilizers (EA included) is thatnitrogen atoms have not been completely removed from the ZnO film at the highest temperature of ourexperiments (600◦C).