EUROPEAN CONGRESS AND EXHIBITION ON ADVANCED MATERIALS AND PROCESSES - EUROMAT 2021

Two-dimensional (2D) oxides have recently attracted a lot of attention due to their unique electronic and transport properties. In this work, we apply density functional theory (DFT) calculations using local (LDA) and fully nonlocal exchange-correlation functionals (HSE06/PBE0) to investigate the effect of the number of layers on the structural and electronic properties of litharge SnO and PbO. Tin monoxide (SnO) is a p-type transparent oxide semiconductor that can also show ambipolar conductivity with doping, but its small bandgap (0.7eV) can be an obstacle for its application as a transparent conductor or photocatalytic material. Alpha lead-oxide (α-PbO) ultrathin sheets have been proposed as excellent candidates for solar cells. Here, we examine the properties of both materials and we show the strong effect of the number of layers on the band structure and the tunability that this method offers. We calculate the band alignment and work functions. We propose that the SnO/PbO heterojunction with a broken bandgap alignment may be used in an-all oxide tandem solar cell, whereas PbO nanostructures can be attractive for photocatalysis and energy conversion, as in the application of PbO/SnO2 heterostructures. The growth of PbO/SnO2 nanostructures is presented.