On the adsorption mechanism of caffeine on MAPbI(3) perovskite surfaces: a combined UMC-DFT study

Autor(es)

Ribeiro Junior, Luiz A. ^{[1, 2]} ; Tromer, Raphael M. ^[3] ; dos Santos, Ramiro M. ^[1] ; Galvao, Douglas S. ^{[3, 4]}

Afiliação do(s) autor(es)

^[1] Univ Brasilia, Inst Phys, BR-70919970 Brasilia, DF - Brazil

^[2] Univ Brasilia, PPGCIMA, Campus Planaltina, BR-73345010 Brasilia, DF - Brazil

^[3] Univ Estadual Campinas, Appl Phys Dept, Campinas, SP - Brazil

^[4] Univ Estadual Campinas, Ctr Comp Engn & Sci, Campinas, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Physical Chemistry Chemical Physics; v. 23, n. 18, p. 10807-10813, MAY 14 2021.
• Citações Web of Science: 0

Resumo

Recently, it was experimentally shown that the performance and thermal stability of the perovskite MAPbI(3) were improved upon the adsorption of a molecular layer of caffeine. In this work, we used a hybrid methodology that combines uncoupled monte carlo (UMC) and density functional theory (DFT) simulations to carry out a detailed and comprehensive study of the adsorption mechanism of a caffeine molecule on the surface of MAPbI(3). Our results showed that the adsorption distance and energy of a caffeine molecule on the MAPbI(3) surface are 2.0 angstrom and -0.3 eV, respectively. The caffeine/MAPbI(3) complex presents a direct bandgap of 2.38 eV with two flat intragap bands distanced 1.15 and 2.18 eV from the top of valence bands. Although the energy band levels are not significantly shifted by the presence of caffeine, the interaction MAPbI(3)/perovskite is enough to affect the bands' dispersion, particularly the conduction bands. (AU)

• Processo FAPESP: 13/08293-7 - CECC - Centro de Engenharia e Ciências Computacionais
• Beneficiário: Munir Salomao Skaf
• Modalidade de apoio: Auxílio à Pesquisa - Centros de Pesquisa, Inovação e Difusão - CEPIDs