Temperature-modulated space-charge-limited-current spectroscopy (TMSCLC) is applied to quantitatively evaluate the density of trap states in the band-gap with high energy resolution of semiconducting hybrid lead halide perovskite single crystals. Interestingly multicomponent deep trap states were observed in the pure perovskite crystals, which assumingly caused by the formation of nanodomains due to the presence of the mobile species in the perovskites.

Novel ethyladamantyl solubilization side groups were found to induce π–π interactions between the conjugated cores through adamantyl–adamantyl stacking in soluble diketopyrrolopyrrole (DPP) derivatives. The closeness of the DPP cores amplifies charge transfer in the material, as far as the π–π interaction is a dominant charge-hopping pathway. As a result, tenfold enhancement of hole mobilities exceeding those obtained for insoluble derivatives was reached. Moreover, due to high crystallinity and co-planarity of the conjugated cores, electron transfer was preserved with a mobility of 0.2 cm² V⁻¹ s⁻¹ for dithiophene-DPP. At the same time, the material remained soluble, which is a significant advantage for purification and processing. This approach can be universally applied for many types of semiconducting organic materials containing the imide motif, where solubilization is achieved by side-group substitution.

The efficiency of organo-lead halide perovskite-based optoelectronic devices is dramatically lower for amorphous materials compared to highly crystalline ones. Therefore, it is challenging to optimize and scale up the production of large-sized single crystals of perovskite materials. Here, we describe a novel and original approach to preparing lead halide perovskite single crystals by applying microwave radiation during the crystallization. The microwave radiation primarily causes precise heating control in the whole volume and avoids temperature fluctuations. Moreover, this facile microwave assisted method of preparation is highly reproducible, fully automated and it can be applied for various different perovskite structures. In addition, this cost-effective method is expected to be easily scalable because of its versatility and low energy consumption. The crystallization process has low heat losses, therefore only a low microwave reactor power of 8–15 W during the temperature changes and of less than 1 W during the temperature holding is needed.