Intro; Supervisor's Foreword; Abstract; Acknowledgements; Contents; 1 Introduction; 1.1 Introduction; 1.2 Crystal Structure of Monolayer and Bulk InSe; 1.3 Electronic and Optical Properties: Bulk Crystal; 1.4 Few-Layer and Monolayer Ultrathin Films; 1.5 Density Functional Theory Bands for Monolayer InSe; 1.6 Other Layered Hexagonal III-VI Semiconductors; References; 2 Tight-Binding Model; 2.1 Tight-Binding Model for Monolayer InSe; 2.1.1 Hamiltonian; 2.1.2 Parametrisation of Hamiltonian with Scissor Correction; 2.2 Multilayer Films; 2.2.1 Bilayer Hamiltonian and Parametrisation

3.4.1 Quantisation of Bulk InSe Bands in Ultrathin Films3.4.2 Intersubband Optical Transitions; 3.4.3 Effects of Interlayer Screening in Gated n-Doped InSe; 3.4.4 Dual Gating; 3.4.5 Experimental Realisation of Intersubband Transitions; References; 4 Spin-Orbit Coupling Effects in InSe Films; 4.1 Modelling of Spin-Orbit Coupling; 4.1.1 Spin-Orbit Coupling in the Tight-Binding Model; 4.1.2 Hybrid kcdotp Tight-Binding Theory; 4.2 Rashba Spin-Orbit Coupling; 4.2.1 Rashba Splitting in the Hybrid kcdotp Tight-Binding Model; 4.2.2 Electrostatic Doping

4.3 Selection Rules for Interband Optical Transitions4.3.1 Hybrid kcdotp Tight-Binding Theory; 4.3.2 Optical Absorption Including SOC in the Tight-Binding Model; 4.3.3 Optical Pumping of Nuclear Spin Polarisation; References; 5 Conclusions; References; Curriculum Vitae