Crafting Complex Hybrid Materials for Sustainable Energy Conversion

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With an unprecedented rise in solar cell efficiencies and ease of fabrication, hybrid lead halide perovskites (PbHP) have gained worldwide popularity. However, these materials still rely on the use of toxic Pb and lack of long-term stability. Moreover, distracted by a race for higher conversion efficiencies, the development of in-vacuum deposition techniques to reproducibly and controllably grow these hybrid films has been highly overlooked. This is now the main hurdle for the full exploration of Pb-free and stable hybrid halides, which might not be as defect tolerant or easily produced by solution process as PbHP. Therefore, a revolutionary method allowing the discovery of new sustainable complex hybrid materials is now, more than ever, of paramount importance. Here I describe a completely new approach that allows stoichiometric and layer-by-layer in-vacuum deposition of wide families of organic-inorganic materials, and their mixture in any pre-determined ratio. To overcome the specific challenges of hybrid film growth (incompatible volatility and solubility) I propose Pulsed Dual-Laser Deposition (PDLD) to decouple the deposition of the inorganic and organic sources with two distinct laser sources, a high energy (UV) and a low energy (IR), all in one vacuum system. Only this decoupling will allow the control and versatility to bridge the hybrid materials discovery gap and to tackle open scientific questions regarding the interplay between the organic and inorganic components, defect nature and their influence on optical properties, carrier scattering and recombination phenomena. Combining these fundamental insights with controlled growth, will enable the design of a new generation of stable and non-toxic hybrid films. My extensive experience in in-vacuum materials synthesis for solar cells, supported by the unique PLD expertise at the host institution will enable a leap in the discovery and understanding of hybrid materials for solar energy conversion and beyond.