Abstract
Halogenated hybrid perovskites, only marginally studied since the late 1990s, notably for their light-emitting properties, emerged spectacularly a decade ago in the context of photovoltaics. With sunlight conversion efficiencies now approaching those of silicon, these materials have opened up new potential for solar cell design.
The material's particular physical properties are at the root of this dazzling success. Fundamental studies of the material reveal that halogenated hybrid perovskites possess a set of favorable properties for photovoltaics, rarely present at the same time in other types of materials: a high absorption coefficient, low excitonic effects, a bandgap energy allowing good collection of photons coming from the Sun, good transport properties, high tolerance to defects. What's more, these physical properties can be modulated by chemical engineering, enabling perovskites to be optimized to meet the various challenges of photovoltaics, such as stability or multi-junction cells.
