Intramolecular Noncovalent Interaction‐Enabled Dopant‐Free Hole‐Transporting Materials for High‐Performance Inverted Perovskite Solar Cells

Abstract

Intramolecular noncovalent interactions (INIs) have served as ap owerfuls trategy for accessing organic semiconductors with enhanced charge transport properties.Herein, we apply the INI strategy for developing dopant-free holetransporting materials (HTMs) by constructing two smallmolecular HTMs featuring an INI-integrated backbone for high-performance perovskite solar cells (PVSCs). Upon incorporating noncovalent S•••O interaction into their simplestructured backbones,t he resulting HTMs,B TORA and BTORCNA, showed self-planarized backbones,t uned energy levels,enhanced thermal properties,appropriate film morphology,a nd effective defect passivation. More importantly,t he high film crystallinity enables the materials with substantial hole mobilities,t hus rendering them as promising dopant-free HTMs.C onsequently,t he BTORCNA-based inverted PVSCs delivered ap ower conversion efficiency of 21.10 %w ith encouraging long-term device stability,o utperforming the devices based on BTRA without S•••O interaction (18.40 %). This work offers ap ractical approach to designing charge transporting layers with high intrinsic mobilities for highperformance PVSCs.

Isomeric Acceptor–Acceptor Polymers: Enabling Electron Transport with Strikingly Different Semiconducting Properties in n-Channel Organic Thin-Film Transistors

“…This difference is consistent with the UV–vis absorption spectra of P­(BTI-2-BTzE) and P­(BTI-5-BTzE), where the aggregation for the former is much stronger than that for the latter (Figure S16). As shown in Figure a, the distance between S (thienyl) and O (carbonyl) is 2.67 Å, which is shorter than the sum of S and O van der Waals radius of 3.32 Å, indicating significant noncovalent S···O interactions . On the other hand, the S···N distance in the polymer P­(BTI-2-BTzE) is 3.11 Å, which is shorter than the sum of S and N van der Waals radius of 3.35 Å, indicating that the 2,2′-bithiazole moiety can form intramolecular noncovalent S···N interactions along the polymer backbone.…”

“…As shown in Figure 3a, the distance between S (thienyl) and O (carbonyl) is 2.67 Å, which is shorter than the sum of S and O van der Waals radius of 3.32 Å, indicating significant noncovalent S•••O interactions. 45 On the other hand, the S•••N distance in the polymer P(BTI-2-BTzE) is 3.11 Å, which is shorter than the sum of S and N van der Waals radius of 3.35 Å, indicating that the 2,2′-bithiazole moiety can form intramolecular noncovalent S•••N interactions along the polymer backbone. Furthermore, the energy barrier of reverse rotation between two thiazole units was also evaluated by DFT calculations (Figure S17), and there is a 1.8 kJ mol −1 energy barrier from the stable state to the metastable state for the 2,2′-bithiazole unit, which is larger than that (0.4 kJ mol −1 ) of the isomeric 5,5′-bithiazole unit.…”

Conjugation Engineering of Spiro-Based Hole Transport Materials for Efficient and Stable Perovskite Solar Cells

“…Perovskite solar cells (PSCs) have emerged as a promising candidate for the next-generation commercialized photovoltaic (PV) technology due to their excellent photoelectric performance. − In the past decade, organic − and polymeric − hole transport materials (HTMs) have been extensively studied because they play an important role in efficient charge transport. So far, spiro-type HTMs such as Spiro-OMeTAD are the most widely used organic HTMs for n-i-p PSCs .…”

Tailoring Defects Regulation in Air-Fabricated CsPbI3 for Efficient Inverted All-Inorganic Perovskite Solar Cells with Voc of 1.225 V

“…The integrated current densities in the EQE spectra (Figure d) are 19.63, 19.42, and 19.17 mA/cm 2 for the devices with FBJ, with FPEAI and Ref, which are well matched with the measured J sc . Transient photocurrent (TPC) and transient photovoltage (TPV) measurements are performed to investigate the carrier transport in the devices. , Compared with the Ref and FPEAI doped devices, the target device reveals the slowest decay of photovoltage (Figure e) and shortest lifetime at the TPC measurements (Figure S16). Thus, it directly uncovers that the less nonradiative recombination and promoted carrier transports for FBJ incorporation are the origination of the superior photovoltaic performance with recorded V oc .…”