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 dihydrate as precursor salt and one among the following aminoalcohols: aminopropanol (APr), aminomethyl butanol (AMB), aminophenol (APh) and aminobenzyl alcohol (AB) as stabilizing agent. Their thermal decomposition process has been analyzed in situ by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and evolved gas analysis (EGA), whereas the solid product has been analysed ex-situ by X-ray diffraction (XRD) and infrared spectroscopy (IR). Although, except for the APh ink, crystalline ZnO is already obtained at 300 ºC, the films contain an organic residue that evolves at higher temperature in the form of a large variety of nitrogen-containing cyclic compounds. The results indicate that APr can be a better stabilizing agent than ethanolamine (EA). It gives larger ZnO crystal sizes with similar carbon content. However, a common drawback of all the amino stabilizers (EA included) is that nitrogen atoms have not been completely removed from the ZnO film at the highest temperature of our experiments (600 ºC).

Role of Ethanolamine on the Stability of a Sol–Gel ZnO Ink

“…Next reaction with -OH would give lactams or lactims.As a complementary experiment, Evolved Gas Analysis was used to elucidate the composition of the samples before and after degradation under illumination in air. A variety of mass fragments from m/z = 12 to 86 was detected from the inks, and their respective EGA curves were classified according to their dependence on temperature24,38 . In particular, the group related with m/z = 76 (Figure 5a) can be associated with some non-bonded and degraded EA decomposition fragments 39 .…”

From Ethanolamine Precursor Towards ZnO—How N Is Released from the Experimental and Theoretical Points of View

“…When several volatiles evolve simultaneously, the intensity of some fragments results from the contribution of different volatiles rendering their identification difficult. To simplify the analysis, we have proceeded, as in our previous study on several aminoalcohols, [4] and considered that the fragments arising from a single volatile will follow the same temperature dependence. Consequently, the fragments have been classified according to their intensity dependence on temperature (details are given in Figure S1A–E) and one representative fragment of each group has been plotted in Figure S1F.…”

“…ZnO-based nanomaterials are crucial in various areas, including biological, optical, photocatalysis, and so forth [1,2,3,4,5,6,7,8,9,10,11,12,13,14]. In general, these nanomaterials are prepared using a zinc(II) salt (usually acetate) and an additional organic ligand to stabilize the precursor [3,4,5,6]. It has also been proven that the purity, morphology and properties of these ZnO nanomaterials depend on several factors (i.e., additional reactants, solvents, temperature, experimental conditions etc.)…”

“…It is well known that aminoalcohols, especially ethanolamine (EA), are by far the organic ligands most widely used as stabilizers. Previous studies have revealed that—(a) the tetrameric complex, [Zn] 4 , formed in the reaction of zinc acetate dihydrate (ZAD) with EA is clearly more stable in solid than in solution, where monomeric and dimeric species ([Zn] 1 and [Zn] 2 , respectively, shown in Figure 1) prevail [3,4]; (b) the dinuclear compound [Zn] 2 is expected to have a key role in the transformation of the precursor into ZnO-based nanomaterials [14]; and (c) tiny changes in the aminoalcohol are important as to affect the N content in the final materials [4] and, therefore, their properties and potential applications. A deep knowledge of the number of steps and the changes involved therein would provide valuable information to minimize some of the problems of ZnO-based nanomaterials (e.g., presence of traces of N) and therefore to improve their quality for technological applications.…”

Solution processed CZTS solar cells using amine–thiol systems: understanding the dissolution process and device fabrication

“…At the same time, a good understanding of the molecular structures of the solutes would benefit further development of precursor inks for photovoltaic applications. Thermogravimetric analysis (TGA) of inks containing ethanolamine complexes of various metals carried out by Vila 34 revealed that the majority of the ethanolamine evaporated by B200 1C. In our previous reports, 30,31 spray deposition of inks based on ethanolamine or water onto a hotplate had been attempted, but this technique had proven difficult due to the high viscosity of the solutions.…”