Banca de QUALIFICAÇÃO: HELDER MOREIRA BRAGA

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : HELDER MOREIRA BRAGA
DATE: 28/03/2024
TIME: 13:00
LOCAL: Bloco B - Sala a ser confirmada
TITLE:

THE APbX3 QUANTUM DOTS EFFECTS IN THE CHARGE TRANSPORT IN PEROVSKITE SOLAR CELLS

PAGES: 99
BIG AREA: Ciências Exatas e da Terra
AREA: Física
SUMMARY:

Perovskite solar cells (PSCs) are gaining prominence as a promising class of semiconductor materials for solar energy conversion due to their remarkable efficiency, easy manufacturing, and cost-effectiveness. On the other hand, sPbX3 halide perovskite quantum dots (QDs) manifest intrinsic properties that make them attractive for optoelectronic applications, including low defect density, compatibility with large-scale deposition techniques, and a customizable bandgap. Furthermore, all-inorganic perovskite exhibits superior stability under environmental conditions compared to organic-inorganic hybrid perovskite materials. To increase the long-term stability of PSCs, a proven strategy involves applying
moisture-resistant layers to the perovskite surface. Consequently, QDs emerge as promising candidates for interface engineering in PSCs due to their stability and tunable bandgap position. In this study, we investigated the impact of CsPbX3 QDs on the morphology, optical and structural properties of PSK layers. The incorporation of CsPbBr3 QDs into PSK films was carried out by depositing their suspension on the surface of the TiO2 substrate, followed by the formation of the MAPbI3 PSK film through the sequential deposition method . Another approach involved the deposition of CsPbBr3 QDs onto the
MAPbI3 layer, resulting in a PSK film with QDs on its surface. Preliminary scanning electron microscopy results reveal that the presence of QDs induces distinct morphologies depending on the position at which the QDs were deposited on the PSC. However, PSK films with QDs on their surfaces exhibit slightly different morphologies, with QDs distributed among the PSK grains. X-ray diffraction results suggest that the introduction of QDs maintains the integrity of the perovskite structure and the appearance of the
orthorhombic phase of the QDs. Furthermore, the photovoltaic results indicate that the QDs layer does not impact the transport of electrons and holes in the units. Ongoing experiments involving durability are underway to analyze the possible stabilization of devices with QDs. Furthermore, experiments are underway incorporating CsPbI3 QDs similarly to that carried out for CsPbBr3 QDs.

COMMITTEE MEMBERS:
Presidente - Interno ao Programa - 2249395 - THIAGO BRANQUINHO DE QUEIROZ
Membro Titular - Examinador(a) Interno ao Programa - 1545738 - MARCIA TSUYAMA ESCOTE
Membro Titular - Examinador(a) Interno ao Programa - 1282172 - ROBERTO GOMES DE AGUIAR VEIGA
Membro Titular - Examinador(a) Externo ao Programa - 2351974 - JULIANA DOS SANTOS DE SOUZA
Membro Suplente - Examinador(a) Interno ao Programa - 1305186 - SERGIO BROCHSZTAIN
Membro Suplente - Examinador(a) Interno ao Programa - 1760527 - FLAVIO LEANDRO DE SOUZA
Membro Suplente - Examinador(a) Interno ao Programa - 1309493 - PEDRO ALVES DA SILVA AUTRETO
Membro Suplente - Examinador(a) Externo ao Programa - 3066318 - JULIAN ANDRES MUNEVAR CAGIGAS