Atomic-Scale Insights into Emergent Photovoltaic Absorbers

Abstract

I owe a huge debt of gratitude to my supervisor Dr David Scanlon -initially for taking the risk of hiring an organic chemist, and subsequently for his generous advice and support throughout the last four years. I feel incredibly fortunate to have had the opportunity of his mentorship. I would like to thank all members of the Scanlon Materials Theory Group. In particular, special thanks go to Chris Savory for being the font of all learning, Dr Ben Williamson for his discerning taste in figures, Dr Katie Inzani for her knowledge of pre-1990s music, and Dr Adam Jackson for many in-depth discussions. Additional thanks go to the long-lost members of KLB room 349, including Dougal, Ian, Mia, and Rachel, for the constant supply of beer and conversation.Prof. Aron Walsh and many of his current/ex-group members, including Jarvist, John, Keith, Dan, Chris, Suzy, and Lucy have been excellent fun at conferences and never stopped answering my Slack questions. Particular thanks go to Prof. Jamie Neilson and Annalise Maughan at CSU for making my visit so enjoyable. Prof. Brent Melot, Prof. Louis Piper, Dr Anna Regoutz, and Dr Ben Morgan deserve thanks for the number of drinks they have bought me at conferences.

Perspectives and Design Principles of Vacancy-Ordered Double Perovskite Halide Semiconductors

“…This interaction occurs across a distance of ∼4 Å between octahedra, due to the disperse projection of the iodine 5p orbitals into the interoctahedral void and acts to stabilize the bonding at this k -point. In contrast, at the X point, the A 1 g antibonding orbital is out of phase with the A 1 g orbital in the adjacent cell (Figure d), resulting in an antibonding interaction between neighboring octahedra (Figure e) . As such, the energy of the interaction at the X point is significantly higher, giving rise to reasonably high band dispersion.…”

“…The isosurface level was set to 0.008 eV Å –3 . Figure reproduced with permission from ref . Copyright 2018 University College London.…”

Titanium‐Based Vacancy‐Ordered Double Halide Family in Perovskite Solar Cells

“…Most lead‐free double perovskites exhibited indirect bandgaps, owing to a mismatch in angular momentum of the frontier electronic orbitals. [ 44 ] In achieving an ideal bandgap while catering to the high and indirect bandgap issue of Cs 2 TiBr 6 , Ti can partially be replaced with another cation. Through DFT calculations (VASP), Shrivastava et al studied the impact of partial substitution of the Ti atom with other cations, specifically Sn and Pb, resulting in compounds with a chemical formula Cs 2 Ti 1– x M x Br 6 [ 45 ] where M = Sn and Pb.…”

2D Particle-in-Cell/Monte Carlo Collision Simulation of Zn-C Mosaic Target Erosion

“…Currently, there is a growing trend to synthesize films that are single-layer nanohybrid composites that can meet these requirements [1][2][3][4][5]. The properties of films can be further modified by changing their thickness or using complex multilayer heterostructures based on superlattices and gradient structures [6][7][8][9]. These nanohybrid compounds consist of several components and are based on oxides, nitrides, or carbides.…”