Hot carrier solar cells: Principles, materials and design

The concept of hot carrier solar cells is discussed in terms of carrier cooling, conditions of energy- and carrier-selectivity for the energy selective contacts and macroscopic device behaviour. From the findings for hot carrier absorbers, we carried out high accuracy density functional calculations of hydrogen-terminated diatomic molecules, with results used in an infinite diatomic chain model for estimating phononic properties of material candidates. We evaluate phonon confinement as a function of structure size and intentional material mismatch, relating the accompanying constraints in electronic properties to the requirements of hot carrier absorbers. The evaluation of material candidates for hot carrier absorbers and energy selective contacts regarding their phononic, electronic, optical and structural properties provides us with a more detailed description of a practicable hot carrier solar cell.