| Abstract [eng] |
Characterization of Upconverting Metal-Organic Frameworks During this Master‘s thesis there was finished one-step synthesis of metal-organic frameworks (MOFs) with one and two upconversion luminescence centre consisting of lanthanide nitrates and benzene-1,3,5-tricarboxylic acid (H3BTC) as organic precursor. For these synthesis to be done it was not necessary for expensive autoclave equipment which is characteristic for solvothermal method. By characterizing upconversion properties of new MOFs it was determined that only Er3+ can be used as activator for one centre luminescence upconversion by ground state absorption/excited-state absorption (GSA/ESA) mechanism, while Yb3+, Ho3+, Tm3+ and Nd3+ ions cannot. Also, it was established that BTC cannot initiate triplet-triplet annihilation upconversion (TTA-UC) as this mechanism sensitizer. Yb3+-Er3+ and Yb3+-Ho3+ ion pairs as sensitizer-activator are suitable for two centre luminescence upconversion by GSA/excited-state upconversion (GSA/ESU) mechanism. Yb3+-Tm3+ pair, contrary as show examples in literature review, does not exhibit upconversion properties in newly synthesized MOFs. |
