Perovskite solar cells (PSCs) currently reach high efficiencies, while their insufficient stability remains an obstacle to their technological commercialization. The introduction of hole-transport materials (HTMs) into the device structure is a key approach for enhancing the efficiency and stability of devices. However, currently, the influence of the HTM structure or properties on the characteristics and operational stability of PSCs remains insufficiently studied. Herein, we present four novel push-pull small molecules, H1-4, with alternating thiophene and benzothiadiazole or fluorine-loaded benzothiadiazole units, which contain branched and linear alkyl chains in the different positions of terminal thiophenes to evaluate the impact of HTM structure on PSC performance. It is demonstrated that minor changes in the structure of HTMs significantly influence their behavior in thin films. In particular, H3 organizes into highly ordered lamellar structures in thin films, which proves to be crucial in boosting the efficiency and stability of PSCs. The presented results shed light on the crucial role of the HTM structure and the morphology of films in the performance of PSCs.

Here, we present a synthesis of three novel conjugated block-copolymers (BCP) with general formula P3HT-bridge-TBO, where P3HT is a poly(3-hexyl)thiophene, TBO is a thiophene-benzothiadiazole block, and the bridge is composed of two fluorene units (FF) or two thiophenes (TT) or a mixture (TF). It is demonstrated that the physicochemical properties of the materials with different bridges are similar. Furthermore, P3HT-bridge-TBO materials are investigated in PSCs with classical n-i-p configuration for the first time. PSCs with BCPs reach average efficiencies with a top of 14.4% for P3HT-FF-TBO. At the same time, devices demonstrate spectacular long-term operation stability after 1000 h under constant illumination with minor changes in efficiency, while PSCs with state-of-the-art hole-transport layer demonstrate unstable behavior. This groundbreaking work demonstrates the potential of BCP to ensure the stable operation of perovskite photovoltaics.

Four photoacid generators such as triphenylsulfonium triflate and nonaflate, 4-tert-butylphenyl(diphenyl)sulfonium nonaflate and tris(4-tert-butylphenyl)sulfonium nonaflate were synthesized, and their spectral characteristics were investigated in the polymer matrix. The dependence of the photosensitivity of resist films on the efficiency of absorption of actinic radiation and the quantum yields of acid generation was found. Triphenylsulfonium triflate salt and tris(4-tert-butylphenyl) sulfonium nonaflate were shown to be promising photoacid generators with a resist sensitive to irradiation by ArF and KrF excimer lasers, respectively.

Thermally induced morphological reorganization of hole-transporting materials (HTMs) is an effective pathway to enhance the performance of perovskite solar cells (PSCs).