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• The new materials of T-6TPA with high hole mobility of 2.06 × 10−3 cm2V−1s−1 was synthesized for dopant‐free HTL. • The infiltration strategies can further improve the interface hole extraction and transport between HTL and perovskite. • Anti-solvent drip strategy can construct a more effective charge transport channel in the perovskite. • The PCE of PSC with dopant-free T-6TPA HTL has increased from 18.5% to 20.3% with the assistance of antisolvent dripping. • The PSCs with T-6TPA dopant-free HTL presents good long-term stability in both humid air and high temperature of 60 °C. Perovskite solar cells (PSCs) with dopant‐free hole transporting layers (HTLs) deserved extensive research by merits of their outstanding hydrophobicity and stability. However, the low carrier mobility and poor interfacial hole extraction lead to the inferior power conversion efficiency (PCE) than that of conventional Li+ doped Spiro-OMeTAD. Here, a design of triphenylamine groups grafted triphenylene derivative (T-6TPA) as dopant-free HTLs has been presented. The larger π-conjugation in T-6TPA give rise to high hole mobility of 2.06 × 10−3 cm2V−1s−1. Moreover, the interfacial hole extraction of T-6TPA was significantly promoted when the molecules were infiltrated into perovskite before HTL deposition. The infiltration method of anti-solvent dripping (An) strategy increased PCE from 18.5% up to 20.3%, which is superior to another additive doping strategy (Ad-strategy, 19.3%). The effectiveness of An-strategy can be attributed to the construction of a coherent and homogeneous hole transport channel. The hydrophobicity and high glass transition temperature of T-6TPA also granted excellent moisture and thermal stabilities that the initial PCE could remain 80% for 60 days in air or 600 h at 60 °C. This work highlights the synergistical optimization by design of highly hole-mobile materials as well as the interfacial network construction for charge transport. [ABSTRACT FROM AUTHOR]

[Display omitted] • The strategy of FAECDIP simultaneously realizes mixed-halide and doping for efficient deep-blue PQDs. • Ca2+ passivates the defects and enhances the exciton binding energy of PQDs to favor structural stability and carrier transportation. • The Ca2+-introduced deep blue PeLED enables a record EQE of 5.88 % (447 nm) with a CIE of (0.158, 0.018) up to date. Despite the impressive development of perovskite light-emitting diodes (PeLEDs), it is still challenging to achieve high-efficiency deep-blue PeLEDs using colloid perovskite quantum dots (PQDs). The efficiency of PQDs with a wavelength below 460 nm, which meets the requirements for deep-blue emission in the Telecommunication Union UHD television standard (ITU REC. 2020), lags far behind those of their sky-blue counterparts. To address this issue, a novel strategy of fast anion-exchange & cation-doping inter-promotion (FAECDIP) is proposed to achieve highly efficient deep-blue PQDs by introducing CaBr 2 into the CsPbCl 3 PQDs. Owing to the presence of Ca2+, the speed of ion exchange is increased, driven by the smaller cation, Ca2+, improving the preparation efficiency. Additionally, Ca2+ was doped on the surface of PQDs. Based on studies of fast anion-exchange and theoretical calculations, Ca2+ improves the optical performance by decreasing the number of traps and increasing the crystallinity of target PQDs, facilitating the stability of treated films and PeLEDs by enhancing the formation energy of halogen vacancies. Here, a high PLQY of 80.3 % CaBr 2 -induced CsPb(Cl/Br) 3 deep-blue PQDs (∼446 nm) was achieved. The correspondent PeLEDs (∼447 nm) achieved a superior EQE of 5.88 %, which is the state-of-the-art among the reported deep-blue PeLEDs. Our strategy provides a potential route to achieve deep-blue PeLEDs, which differs from the previous tedious-complex methods. [ABSTRACT FROM AUTHOR]

[Display omitted] • Lewis base groups are introduced into HTMs to restrict ion migration of Li+. • Phen-TPA effectively restricts ion migration of Li+ by strong coordination effect. • PSC based on Phen-TPA achieves a PCE of 20.02% with negligible hysteresis effect. • PSC based on Phen-TPA exhibits preferable humid and thermal stability. • The performance of PSCs is promoted with enhanced coordination ability of HTMs. Li-TFSI as an indispensable dopant for hole transporting materials (HTMs) suffers from inherent hydrophilicity and ion migration, which seriously damages the stability of perovskite solar cells (PSCs). Herein, a facile design strategy is proposed to restrict ion migration of Li+ by introducing different Lewis base groups (pyridine, 1,10-phenanthroline and pyrazine) into HTMs. Owing to the coordination effect of Lewis base groups to Li+, the doped HTMs (Pyrd-TPA, Phen-TPA and Pyra-TPA) exhibit significantly enhanced conjugation and hole mobility. Particularly, theoretical calculation and Fourier-transform infrared spectroscopy (FTIR) results demonstrate that Phen-TPA forms the strongest coordination with Li+ due to the most negative electrostatic potential region existing around 1,10-phenanthroline group. The generated Li+-coordinated Phen-TPA contributes to preferable energy levels, morphology uniformity and hydrophobicity. Element mapping analysis shows that Li-ion migration in doped Phen-TPA is restricted effectively. In addition, Phen-TPA can also passivate the perovskite surface defects dramatically, which facilitates more efficient charge transfer to hole transporting layer. Consequently, PSCs based on Phen-TPA achieve promising power conversion efficiency (PCE) of 20.02% with negligible hysteresis effect. More importantly, it maintains over 88% of the initial PCE after 1056 h storage in ambient condition of 40–60% RH and about 81% of the original efficiency after 264 h storage at 60–70 °C. This work systematically revealed the relation between coordination ability of HTMs and the performance of PSCs for the first time, which provides new design strategies to develop efficient and stable PSCs. [ABSTRACT FROM AUTHOR]

[Display omitted] • Completely cross-linked film is obtained on the basis of photoinitiator markedly lowering the cross-linking temperature. • Hole mobility is enhanced by adding photoinitiator. • Energy levels become more suitable through doping photoinitiator. • Cross-linked hole transport layer improves power conversion efficiency of perovskite solar cells. To the best of our knowledge, poor environment stability is the main challenge for perovskite solar cells (PSCs). In this study, cross-linked hole transport layer (HTL) is built on perovskite crystal to guarantee the operation stability of mesoporous PSCs for the first time. Here, N,N' -di-p-tolyl- N,-N' -bis(4-vinylphenyl)-[1,1′-biphenyl]-4,4′-diamine (V-p-TPD) was applied as a hole-transportable polymerizable monomer with the assistance of ultraviolet photoinitiator 4-octyloxydiphenyliodonium hexafluoroantimonate (OPPI). Cross-linking process is conducted at a distinctly low temperature of only 100 °C by adjusting the V-p-TPD: OPPI ratio to 10:1, which is tolerable for the active black phase of perovskite. The resultant cross-linked V-p-TPD film is qualified with a high cross-linking degree of 99%, a high hole mobility of 3.84 × 10−4 cm2V−1s−1 and a hydrophobic surface with wetting angle of 94.6°. Mesoporous PSCs based on the obtained cross-linked HTL achieved a tremendous Power conversion efficiency (PCE) of 18.49%, which represents the state-of-the-art records of mesoporous PSCs with cross-linkable HTL. PCE of the unpackaged device can remain 88% of the initial value after 30 d in an atmospheric environment with a relative humidity of 60 ± 5%, and maintain 86% of the initial PCE after 200 h in 65 ± 2 °C argon atmosphere. This work presents a low-temperature processing strategy for the preparation of cross-linked HTL layer, which does favor to the stable and efficient energy harvesting application. [ABSTRACT FROM AUTHOR]

• A self-polarization driven CH 3 NH 3 PbI 3 single crystal detector is firstly realized. • The highest responsivity of self-powered photodetectors is 0.16 A/W. • The self-powered photodetectors can work steadily for more than 2 h. The self-powered photodetector (PD) with low energy-consumption is one of the main research direction of the next-generation photoelectric devices. In this paper, a PD driven by ferroelectric polarization based on the CH 3 NH 3 PbI 3 single crystal (100) plane is realized for the first time. The differential scanning calorimetry (DSC) curves of the single crystal and the photocurrent of the device at different temperatures indicate that the crystal possesses a high Curie temperature of 330 K. The working mechanism of self-powered device is demonstrated by characterizing the ferroelectricity and the surface charge distribution on the CH 3 NH 3 PbI 3 single crystal (100) plane. The distortion of the [PbI 6 ] octahedron in the unit cell causes crystal polarization, which provides a driving force for the directional movement of photogenerated carriers within the crystal. The influence of channel direction and channel size on device performance is further studied. The device with a simple structure of Au/CH 3 NH 3 PbI 3 /Au achieves an excellent detection performance. The maximum responsivity is 0.16 A/W, the maximum on–off switching ratio is 1.41 × 104, and the photocurrent of the self-powered device has not been attenuated after continuous operation for 2 h. This provides a design strategy for exploring new self-powered 3D hybrid perovskite PD with broad photoelectricity applications. [ABSTRACT FROM AUTHOR]

• HA+ is incorporated into FAPbI 3 -based perovskite to obtain stable α -FAPbI 3. • 1D-HA-phase exists like a "rivet" passivating among the boundary of perovskite. • 1D/3D hybrid dimension structure enhances the stability of FAPbI 3 -based PSCs. • PSC based (FAMACs) 0.85 HA 0.15 achieves a PCE of 21.20%. FAPbI 3 has been greatly developed in Perovskite solar cells (PSCs) profiting from their narrow bandgap, high panchromatic absorption and long carrier diffusion length. Unfortunately, the phase instability of FAPbI 3 -based perovskite restricts its further development in PSCs. Here, hydrazinium cation (HA+: NH 2 NH 3 +) is incorporated into FAPbI 3 -based perovskite to obtain novel 1D/3D hybrid dimension structure with stable α -FAPbI 3 for the first time. The strong hydrogen bonding of HA+ increases the crystallinity and grain size of perovskite. Furthermore, SEM and TEM reveal that the new HA based 1D-phase (1D-HA-phase) exists like "rivet" passivating among the grain boundary of 3D perovskite, forming 1D/3D hybrid dimension structure contributing to the stability of FAPbI 3 -based perovskite. Confocal fluorescence microscopy, time-resolved photoluminescence spectroscopy and Kelvin probe force microscope measurements reveal that the trap state can be effectively restrained and the non-radiative recombination is largely suppressed in HA+ mixed FAPbI 3 -based perovskite film with 1D-HA-phase. Finally, stable α -FAPbI 3 -based perovskite and its film with high crystallinity, smooth surface morphology, excellent photovoltaic performance and few defects are obtained. PSC using (FAMACs) 0.85 HA 0.15 perovskite achieves a power conversion efficiency of 21.20% which can retain 90% at room temperature in ambient environment for 2520 h. [ABSTRACT FROM AUTHOR]

[Display omitted] • A new strategy of developing high-performance dopant-free HTMs for PSCs is presented. • Two novel HTMs with intramolecular π-π interactions were developed for PSCs. • Crystal structures offer information on molecular configuration and interactions. • PSCs based on BFM-C6 showed a PCE of 19.06% with enhanced long-term stability. The development of hole-transporting materials (HTMs), especially dopant-free ones, is of great significance for simultaneously improving the efficiency and stability of perovskite solar cells (PSCs). Herein, two molecularly engineered HTMs (BFM-C1 and BFM-C6) featuring intramolecular π-π interactions are designed based on the well-known spiro-OMeTAD and synthesized via simple synthetic routes. Unlike the spiro-OMeTAD with orthogonal conformation, both BFM-C1 and BFM-C6 are revealed to adopt a "face-to-face" stacking orientation with evident intramolecular π-π interactions, and display about five times higher hole mobilities (≈ 10-4 cm2V-1s−1) than pristine spiro-OMeTAD. Moreover, both the HTMs exhibit high hole extraction capacity likely owing to good electronic contact with the perovskite. Notably, the incorporated long alkyl chains endow BFM-C6 with better film morphology and superior hydrophobicity, as compared with BFM-C1 , thereby resulting in enhanced charge extraction at the perovskite/HTM interface as well as the moisture stability of the perovskite underneath. Consequently, the PSCs employing BFM-C6 as HTM without dopants achieve a power conversion efficiency of 19.06%, along with preferable durability. Furthermore, BFM-C6 -based PSCs also exhibit improved thermal stability as compared to the devices based on doped spiro-OMeTAD. This work not only enriches the variety of dopant-free HTMs for PSCs, but also provide a new strategy for developing high-performance dopant-free HTMs. [ABSTRACT FROM AUTHOR]

• A green anti-solvent EA method for MA-free quasi-2D DJ phase perovskite films with was reported. • The films presented a more homogeneous phase distribution with reduced defect density, higher mobility and conductivity. • A PCE of 18.86% was obtained, which is the highest for MA-free DJ phase 2D perovskite-based devices. • The devices maintained impressive stabilities under damp heat and continuous illumination at MPP tracking, respectively. The phase distribution of two-dimensional (2D) perovskites is critical for solar cell power conversion efficiency (PCE). Here, we report a simple green anti-solvent (ethyl acetate, EA) method for obtaining uniform phase dispersion of methylamine (MA)-free quasi-2D Dion-Jacobson (DJ) phase perovskite films (DMePDA)FA 3 Pb 4 I 13 (n = 4). The films present a more homogeneous phase distribution for their rapid extraction of solvents and the interaction between Pb2+ and the carbonyl group in EA, resulting in a more shining surface, reduced surface-defect density, higher out-plane mobility, and higher conductivity. We obtain a PCE of 18.86 %, which is the highest for MA-free DJ phase 2D perovskite-based devices. In addition, the target devices maintain 85 % and 90 % of their initial values after 1008 h under 85 % relative humidity at 85 ℃ (ISOS-D-3) and continuous illumination at maximum power point (MPP) tracking at ∼ 45 ℃ (ISOS-L-1), respectively. [ABSTRACT FROM AUTHOR]

[Display omitted] • T5DP36 with one-dimensional transport channel deserved super carrier mobility. • One-dimensional transport channel was firstly constructed in CHTL (T5DP36:V-CBP). • One-dimensional transport channels in CHTL are formed by π-π interaction of T5DP36. • The carrier mobility of CHTL was boosted from 6.6 × 10−5 to 2.16 × 10−3 cm2V−1s−1. • The EQE of blue QLED has increased from 10.03% to 18.16%, which is the cutting edge. Quantum dot light-emitting diodes (QLEDs) emerged as very competitive candidates for next generation display and lighting applications. Cross-linked hole transport materials (HTMs) permit the flourish of solution-processed QLEDs. Whereas, unbalanced charge injection and energy level mismatch happened to cross-linked HTMs severely suppress the efficiency of blue QLEDs, which limits the full-color display application. Here, discoid molecules with self-assembly behavior were firstly proposed to construct one-dimensional transport channels in cross-linked hole transport layer (HTL) to advance the carrier transport property of the target composite HTL (CHTL). Compared with CHTLs prepared from amorphous and disordered crystalline discoid molecules, the carrier mobility of CHTL (T5DP36: V-CBP) with one-dimensional transport channels was signally boosted by two orders of magnitude from 6.6 × 10−5 to 2.16 × 10−3 cm2 V−1 s−1. The relevant blue QLED was qualified with notably enhanced external quantum efficiency of 18.16 %, deep blue emission with Commission International de I'Eclaiiage of (0.14, 0.04) and extended T 50 lifetime from 177 to 417 h under 100 cd m−2. This is at a cutting edge of deep blue light and eligible for high-end display applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • Two novel spiro-type HTMs with a low symmetry feature were developed for PSCs. • The SFHc-S-based PSC achieved a high PCE of 21.52% with improved stability. • Thiocarbonyl groups could efficiently passivate the perovskite surface defects. • Two facilely synthesized spiro cores are reported for designing functional materials. Hole-transporting materials (HTMs) play crucial roles in protecting the perovskite layer, promoting charge extraction, as well as controlling the cost of Perovskite solar cells (PSCs). In order to reduce PSCs cost and simplify PSCs preparation process, more and more attention has been paid to develop multifunctional HTMs. In this work, two novel spiro-fluorene/heterocycle cored bifunctional HTMs, denoted as SFHc-O and SFHc-S respectively, are designed and facilely synthesized. The two HTMs have similar molecular structures, energy levels and thermal properties, but show quite different PSCs performance. Significantly, the heteroatoms in freshly developed spiro cores are demonstrated to have large contributions to device performance. In particular, the sulfur atoms in SFHc-S display a positive impact on both the hole extraction/transport and the defect passivation, which ultimately endow corresponding device with much better performance. The PSC based on SFHc-S obtains a high efficiency excess 21.5% with negligible hysteresis. Moreover, the device with SFHc-S displays enhanced stability, compared to the reference device incorporating spiro-OMeTAD. This work paves a way to develop multifunctional spiro-HTMs for highly efficient and stable PSCs. [ABSTRACT FROM AUTHOR]

[Display omitted] • Highly stable Cs 3 Cu 2 X 5 (X = Cl, Br, I) NCs with near-unity PLQY (X = Cl and I) were prepared by a facile one-pot method. • Crystal phase transformation was observed in water post-treatment of Cs 3 Cu 2 I 5 NCs and a plausible mechanism was proposed. • W-LED constructed by mixing Cs 3 Cu 2 I 5 and CsCu 2 I 3 possessed CIE coordinates of (0.32, 0.34). Cu-based perovskite Nanocrystals (NCs) have a bright future in the field of optoelectronics due to their low toxicity, remarkable optical properties and good environmental stability. However, the industrial application is hindered by complex preparation methods. Herein, a facile one-pot method for synthesizing Cs 3 Cu 2 X 5 NCs is proposed. The target Cu-based perovskite NCs were qualified with preferable optical performance, including near-unity PLQY (X = Cl and I), adjustable spectrum from 441 to 556 nm and remarkable environmental stability (retained more than 50% Photoluminescence (PL) intensity for 2 months in air). Density functional theory (DFT) calculations, Time-resolved PL (TRPL) and temperature-dependent PL spectrum were implemented to explore the Self-trapped excitons (STEs) luminescence mechanism and the roots for remarkable optical performance. In addition, crystal phase transformation was observed in water post-treatment from blue light-emitting Cs 3 Cu 2 I 5 NCs to yellow light-emitting CsCu 2 I 3 NCs, relative characterizations were implemented and a plausible reaction mechanism was proposed. Resultantly, a White light-emitting diode (W-LED) constructed by mixing these two phases was endowed with pure white light, which possessed the Commission Internationale de L'Eclairage (CIE) coordinate of (0.32, 0.34), color temperature of 6053 K, color Rendering index (Ra) 0f 91 and maximum luminance of 1558 cd/m2. The contribution indicates that Cu-based perovskite NCs prepared by one-pot method have great potential for luminescent applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • Indium tin oxide was hybrid modified with MoO 3 and self-assembled monolayer. • Self-assembled monolayer was used to adjust oxygen vacancies in MoO 3. • Solution-processed hole transport layer-free OLED achieved EQE max of 18.18% Compared with current vacuum-deposited multilayer organic light-emitting diodes (OLEDs), solution-processed simplified-structured OLEDs are more appealing by merits of low costs and promising potentials in large-area OLEDs. Nevertheless, it remains challenging due to intermixing between adjacent organic layers. Herein, indium tin oxide (ITO) surface was deposited with molybdenum trioxide (MoO 3) and then modified with self-assembled monolayer (SAM) of pentafluorobenzyl phosphonic acid. The SAM modification process made the MoO x film rich in oxygen vacancies, which ensured effective hole injection from the hybrid modified ITO directly to the emitting layer. This strategy facilitates HTL-free OLEDs and then completely avoids interlayer intermixing. Using the hybrid modified ITO as anode, HTL-free solution-processed green phosphorescent OLED was prepared and achieved a maximum current efficiency of 63.24 cd A−1 and a maximum external quantum efficiency of 18.18%. Meanwhile, preferable operational stability than standard multilayer OLEDs was obtained. For red phosphorescent OLED, a maximum external quantum efficiency of 17.49% was achieved. This work proposed a new way of adjusting cation valence to improve hole injection, contributing to solution-processed OLED fabrication. [ABSTRACT FROM AUTHOR]

• DMF and DMSO induced the termination of perovskite crystals from Pb-X to A-X. • Perovskite crystals with A-X termination have shallower VBM and CBM. • DMSO and DMF induce the regrowth of perovskite crystals with reduced defects. The optimal alignment of semiconductor's electronic energy level with respect to hole-transporting materials (HTMs and ETMs) determines the photovoltaic conversion efficiency of perovskite solar cells (PSCs). The energy level of perovskite can be greatly affected by the crystal surface termination state formed in the perovskite polycrystalline film preparation process. Perovskite featured with Pb-X termination always bears deep energy level which cannot match well HTM. Herein, to regulate the surface termination state of the perovskite crystals, a controlled solvent atmosphere dimethyl sulfoxide (DMSO) and N,N-dimethylformamide (DMF) was employed to induce the regrowth of perovskite crystals. Results prove that the mixed solvent of DMSO and DMF can induce perovskite crystals from Pb-X termination to A-X termination. Density functional theory (DFT) calculations show that the terminated conversion moves the valence and conduction band edge (VBE and CBE) of perovskite crystal to a shallower energy level, which does great favor to match the energy level of HTM, and then contributes to extracting charges. In addition, the defect density of the optimized perovskite polycrystalline film decreased from 1.258 × 1016 to 1.022 × 1016 cm -3, and the depletion width of PSCs increased from 48.9 to 56.1 nm. Profiting from the effective charge extraction and reduced non-radiative recombination, the open circuit voltage of the PSC increased from 0.99 to 1.09 V, and the conversion efficiency boosted from 17.8% to 20.3%.. [ABSTRACT FROM AUTHOR]

• QD films based on modified Poly-TPD exhibited higher PL intensity and lower fluorescence quenching properties. • Reduced defects density at the interface between QD films and Poly-TPD modified with diamine molecules. • QLEDs exhibited a distinctly enhancement in EQE from 4.93 to 8.90%. Inorganic perovskite quantum dots (QDs) have emerged as promising materials for light-emitting devices by merits of their high photoluminescence quantum yield (PLQY), narrow full width at half-maximum and tunable emission spectrum. However, fluorescence quenching and trap-mediated nonradiative recombination between hole transport layer (HTL) and QD films are prejudicial to the performance of perovskite-QDs-based light-emitting devices (QLEDs). Here, HTL was modified with diamine molecules (1,4-butanediamine (4-DA), 1,8-octyldiamine (8-DA) and 1,11-aminoundecylamine (11-DA)) through a simple self-assembly method. QD films based on modified poly[ N , N ′-bis(4-butylphenyl)- N , N ′-bis(phenyl)-benzidine] (Poly-TPD) exhibited higher PL intensity and lower fluorescence quenching properties. Meanwhile, diamine molecules do favor to the flatness of Poly-TPD film and contribute to the smoothness of QD films. Moreover, the exciton quenching and the density of defects at the interface between HTL and QD films were effectively reduced. Particularly, QLEDs based on HTL modified with 8-DA was endowed with a maximum luminance of 78634 cd/m2, a peak current efficiency of 30.77 cd/A, a maximum external quantum efficiency of 8.90% and T 50 of 16.8 min when the initial brightness is about 1000 cd/m2. [ABSTRACT FROM AUTHOR]

• Two ketal derivatives of 9,10-dihydrophenanthrene (DHP) were developed as HTMs for PSCs. • The K-DHP-1 based PSCs delivered a high PCE of 20.52% with negligible hysteresis. • Improved stability was achieved in K-DHP-1 (versus spiro-OMeTAD) based PSCs. • DHP was first revealed as an effective building block for further development of HTMs. It is a very important task of searching for novel hole-transporting materials (HTMs), along with effective building blocks, on the way towards commercialization of the perovskite solar cells (PSCs). 9,10-Dihydrophenanthrene (DHP) is a rigid conjugated system, whose skeleton is closely analogous to the widely used fluorene unit in developing HTMs. Herein, for the first time, DHP employed as a promising building block in the construction of HTMs for PSCs is presented. Two readily-available DHP-cored small molecules, namely K-DHP-1 and K-DHP-2, were synthesized and characterized. An attractive bridged ketal pattern of the two molecules was revealed by the X-ray crystallography of K-DHP-2. Afterwards, the two compounds were applied as HTMs in conventional PSCs with a FA 0.9 MA 0.1 Pb(I 0.9 Br 0.1) 3 • 0.05 CsI perovskite, respectively. Thereinto, the champion device based on doped K-DHP-1 exhibits a power conversion efficiency (PCE) of up to 20.52% with J sc of 23.96 mA/cm2, V oc of 1.09 V and FF of 78.6%, rivalling the performance of device fabricated with spiro-OMeTAD (20.97%). More encouragingly, the K-DHP-1-based PSC displays good long-term stability, remaining 88% of its original performance after storing in atmosphere (30%~50% relative humidity) for 45 d without encapsulation, which is better than the spiro-OMeTAD-based PSC. These results indicate that K-DHP-1 can be an effective HTM to realize high efficiency and stable PSCs, and furthermore DHP can serve as an excellent building block for the development of new HTMs in the future. [ABSTRACT FROM AUTHOR]

• Two vinyl-based cross-linkable hole transporting materials are synthesized. • Cross-linking temperature is markedly lowered by doping photoinitiator. • Hole mobility is also enhanced by doping photoinitiator. • The highest external quantum efficiencies are 15.5% (green) and 15.0% (red). Recently, developing insoluble cross-linkable functional layers plays a vital role for solution-processed organic light emitting diodes (OLEDs). Here, two vinyl-based cross-linkable hole transporting materials V-TPAVTPD and V-TPAVCBP are designed and synthesized. Additionally, cationic photoinitiator 4-octyloxydiphenyliodonium hexafluoroantimonate (OPPI) is first introduced to chemically induce vinyl-based photo cross-linking process, aiming at lowering cross-linking temperature and enhancing hole mobility. As a result, cross-linking can occur at expressly low temperature of 120 °C with >95% solvent resistance. Moreover, hole mobility is markedly enhanced with the value higher than 10−3 cm2 V−1 s−1. When applying hole transporting layers (HTLs) to solution-processed green and red phosphorescent OLEDs, devices exhibit excellent properties. Particularly, the maximum current efficiency of 54.0 cd A−1 (green), 9.8 cd A−1 (red) and external quantum efficiency of 15.5% (green), 15.0% (red) are obtained when OPPI doped V-TPAVCBP serves as HTL. This low temperature feasible cross-linking process to prepare HTLs with preferable hole mobility promotes the development of OLEDs. [ABSTRACT FROM AUTHOR]

• Two pyrene-based hole transport materials are synthesized. • The dopant-free PYR16 using in PSC achieves a higher PCE of 17% than PYR27. • PSC based on dopant-free PYR16 obtains excellent stability at 80 ℃ and under continuous simulated AM 1.5G sunlight soaking. In this work, arylamine branches N 4-[4-[Bis(4-methoxyphenyl)-amino]phenyl]- N 1, N 1-bis(4-methoxyphenyl)-1,4-benzenediamine are introduced to the 1,6- and 2,7-positions of pyrene core to afford two novel HTMs coded PYR16 and PYR27. The influence of different positions of arylamine units on the optical and electronic properties and the performance of PSCs are investigated. The perovskite solar cells (PSCs) using dopant-free PYR16 exhibite a PCE of 17.00%, which is higher than that of PYR27 (14.67%). Furthermore, the PSCs based on PYR16 obtain better stability than those using PYR27 by maintaining 98% of the initial values after 1080 h at 80 ℃ in an ambient environment in the dark and 85% of initial values after 672 h under continuous sunlight soaking in an ambient environment at 45–50 ℃. [ABSTRACT FROM AUTHOR]