Photoresponsive polar LuMnO₃ and nonpolar LaFeO₃ oxides in non-centrosymmetric structures

Yunwei Sheng, Multifunctional Thin Films and Complex Structures (MULFOX) at ICMAB-CSIC

Date: Thursday, 27 October 2022
Time: 10:00 am
Venue: Sala d'Actes Carles Miravitlles, ICMAB-CSIC. Register to attend by Zoom. 

Abstract:

Ferroelectric photovoltaics are receiving a new interest owing to the possible presence of an internal field extending all over the material and the bulk photovoltaic effect (BPE) associated to their non-centrosymmetric character. The BPE in ferroelectrics has been focused on BiFeO3 with a bandgap of 2.7 eV, implying limited responsivity at the visible range. Hexagonal manganites h-ReMnO3 (Re = Lu, Y, etc.) with a narrower bandgap (≈ 1.5 eV) could be promising candidates where BPE had not been documented, and this is the first objective.

Non-centrosymmetry can be intrinsic to the photoabsorber and can be engineered by designing the device. The nonpolar LaFeO3 (bandgap ≈ 2.4 eV) is a good candidate to explore its photoresponsivity to analyze the role of band alignment on photovoltage and compare its photoresponsivity to polar materials.

Supervisors:

• Josep Fontcuberta, MULFOX group, ICMAB-CSIC
• Ignasi Fina, MULFOX group, ICMAB-CSIC

PhD Comittee:

• President: Sylvia Matzen, Paris-Saclay University, France
• Secretary: Mariona Coll Bau, Institut de Ciència de Materials de Barcelona, ICMAB-CSIC
• Vocal: Akash Bhatnagar, Schott AG, Germany

University: Universitat Autònoma de Barcelona (UAB)
PhD Programme: Materials Science PhD Programme

Photocurrent dependence on light polarization angle | Yunwei Sheng