Properties Of Organic Semiconductors Research Articles

Effects of Fluorination on Fused Ring Electron Acceptor for Active Layer Morphology, Exciton Dissociation, and Charge Recombination in Organic Solar Cells.

Fluorination is one of the effective approaches to alter the organic semiconductor properties that impact the performance of the organic solar cells (OSCs). Positive effects of fluorination are also revealed in the application of fused ring electron acceptors (FREAs). However, in comparison with the efforts allocated to the material designs and power conversion efficiency enhancement, understanding on the excitons and charge carriers' behaviors in high-performing OSCs containing FREAs is limited. Herein, the impact of fluorine substituents on the active layer morphology, and therefore exciton dissociation, charge separation, and charge carriers' recombination processes are examined by fabricating OSCs with PTO2 as the donor and two FREAs, O-IDTT-IC and its fluorinated analogue O-IDTT-4FIC, as the acceptors. With the presence of O-IDTT-4FIC in the devices, it is found that the excitons dissociate more efficiently, and the activation energy required to split the excitons to free charge carriers is much lower; the charge carriers live longer and suffer less extent of trap-assisted recombination; the trap density is 1 order of magnitude lower than that of the nonfluorinated counterpart. Overall, these findings provide information about the complex impacts of FREA fluorination on efficiently performed OSCs.

Electronic Properties of Branched Molecular Structures Review

The design of new types of macromolecular architecture is one of the main directions in the development of modern polymer physics. As applied to electronics, electroconductive π-conjugated molecules occupy a special place. In this review, the distinctive features of the electronic properties of organic semiconductors when compared with their solid-state analogs are considered. Special attention is paid to the role of electron–electron and electron–phonon interactions in the formation of self-localized excited states, i.e., solitons and polaritons. The constructive and destructive interference effects in molecular structures containing branching nodes and ring groups are discussed. The size of a branched molecule should herewith be small to conserve quantum coherence. Self-localization effects in such molecules are insignificant and transport is determined by electrons and holes injected from contacts. Two approaches to the description of quantum interference in branched molecules are proposed, notably, based on molecular orbitals and in the scope of the pattern of localized atomic orbitals. These approaches make it possible to formulate design rules for molecular structures, in which interference is observed. The latest results on the design of quantum-interference molecular transistors with ultralow energy consumption are presented. Nonconjugated tree-branched polymers, so-called dendrimers, which can be efficient for designing systems of the collection and transformation of electromagnetic radiation are briefly considered.

Aldol Condensation‐Polymerized n‐Doped Conjugated Polyelectrolytes for High‐Performance Nonfullerene Polymer Solar Cells

Doping provides an efficient strategy to control the electronic properties of organic semiconductors. However, compared with the widely reported p‐type doping protocols, n‐type doping of organic semiconductors still remains a challenge. Herein, a series of novel n‐doped conjugated polyelectrolytes (CPEs) with high doping levels and conductivity are designed. These CPEs are synthesized via a facile, metal‐free, and high‐yield aldol condensation protocol from bis‐isatin and bis‐oxindole monomers. The designed CPEs possess a n‐type electron‐deficient and rigid conjugated backbone, resulting in easy charge delocalization, enhanced n‐doping behaviors, and high conductivity. The evolution on the counterions of these CPEs further alters their n‐doping behaviors, charge transporting properties, and work function tunability, etc. By using these CPEs as electron transport materials (ETMs) for nonfullerene polymer solar cells (NF–PSCs), high power conversion efficiencies (PCEs) over 16% can be achieved when PM6:Y6 is used as the active component. Moreover, these CPEs can enable efficient NF–PSCs even if their thicknesses are up to 60 nm, indicating the potential of these CPEs as thickness‐insensitive ETMs for the fabrication of large‐area NF–PSCs.

Molecular packing-dependent exciton dynamics in functionalized anthradithiophene derivatives: From solutions to crystals.

Understanding the impact of inter-molecular orientation on the optical properties of organic semiconductors is important for designing next-generation organic (opto)electronic and photonic devices. However, fundamental aspects of how various features of molecular packing in crystalline systems determine the nature and dynamics of excitons have been a subject of debate. Toward this end, we present a systematic study of how various molecular crystal packing motifs affect the optical properties of a class of high-performance organic semiconductors: functionalized derivatives of fluorinated anthradithiophene. The absorptive and emissive species present in three such derivatives (exhibiting "brickwork," "twisted-columnar," and "sandwich-herringbone" motifs, controlled by the side group R) were analyzed both in solution and in single crystals, using various modalities of optical and photoluminescence spectroscopy, revealing the nature of these excited states. In solution, in the emission band, two states were identified: a Franck-Condon state present at all concentrations and an excimer that emerged at higher concentrations. In single crystal systems, together with ab initio calculations, it was found in the absorptive band that Frenkel and Charge Transfer (CT) excitons mixed due to nonvanishing CT integrals in all derivatives, but the amount of admixture and exciton delocalization depended on the packing, with the "sandwich-herringbone" packing motif least conducive to delocalization. Three emissive species in the crystal phase were also identified: Frenkel excitons, entangled triplet pairs 1(TT) (which are precursors to forming free triplet states via singlet fission), and self-trapped excitons (STEs, similar in origin to excimers present in concentrated solution). The "twisted-columnar" packing motif was most conducive to the formation of Frenkel excitons delocalized over 4-7 molecules depending on the temperature. These delocalized Frenkel states were dominant across the full temperature range (78 K-293 K), though at lower temperatures, the entangled triplet states and STEs were present. In the derivative with the "brickwork" packing, all three emissive species were observed across the full temperature range and, most notably, the 1(TT) state was present at room temperature. Finally, the derivative with the "sandwich-herringbone" packing exhibited localized Frenkel excitons and had a strong propensity for self-trapped exciton formation even at higher temperatures. In this derivative, no formation of the 1(TT) state was observed. The temperature-dependent dynamics of these emissive states are reported, as well as their origin in fundamental inter-molecular interactions.

The Application of Organic Semiconductor Materials in Spintronics.

π-Conjugated semiconductors, primarily composed of elements with low atomic number, are regarded as promising spin-transport materials due to the weak spin–orbit coupling interaction and hence long spin relaxation time. Moreover, a large number of additional functions of organic semiconductors (OSCs), such as the abundant photo-electric properties, flexibility, and tailorability, endow the organic spintronic devices more unique properties and functionalities. Particularly, the integration of the photo-electric functionality and excellent spin transport property of OSCs in a single spintronic device has even shown great potential for the realization of spin manipulation in OSCs. In this review, the application of OSCs in spintronic study will be succinctly discussed. As the most important and extensive application, the long-distance spin transport property of OSCs will be discussed first. Subsequently, several multifunctional spintronic devices based on OSCs will be summarized. After that, the organic-based magnets used for the electrodes of spintronic devices will be introduced. Finally, according to the latest progress, spin manipulation in OSCs via novel spintronic devices together with other prospects and challenges will be outlined.

Electronic structure spectroscopy of organic semiconductors by energy resolved-electrochemical impedance spectroscopy (ER-EIS)

Organic electronic applications are envisioned to address broad markets, which includes flexible displays, electronic papers, sensors, disposable and wearable electronics, and medical and biophysical applications, leading to a tremendous amount of interest from both academia and industry in the study of devices. These fields of science and technology constitute interdisciplinary fields that cover physics, chemistry, biology, and materials science, leading, as a wanted output, to the elucidation of physical and chemical properties, as well as structures, fabrication, and performance evaluation of devices and the creation of new knowledge underlying the operation of organic devices using new synthesized organic materials—organic semiconductors. We testify the situation when the available organic electronic applications sometimes lack a theoretical background. The cause may be the complicated properties of disordered, weak bounded, molecular materials with properties different from their inorganic counterparts. One of the basic information-rich resources is the electronic structure of organic semiconductors, elucidated by the methods, hardly possible to be transferred from the branch of inorganic semiconductors. Electrochemical spectroscopic methods, in general, and electrochemical impedance spectroscopy, in particular, tend and seem to fill this gap. In this Perspective article, the energy resolved-electrochemical impedance spectroscopic method for electronic structure studies of surface and bulk of organic semiconductors is presented, and its theoretical and implementation background is highlighted. To show the method’s properties and strength, both as to the wide energy and excessive dynamic range, the basic measurements on polymeric materials and D–A blends are introduced, and to highlight its broad applicability, the results on polysilanes degradability, gap engineering of non-fullerene D–A blends, and electron structure spectroscopy of an inorganic nanocrystalline film are highlighted. In the outlook and perspective, the electrolyte/polymer interface will be studied in general and specifically devoted to the morphological, transport, and recombination properties of organic semiconductors and biophysical materials.

Synergistic Effect of Excited State Property and Aggregation Characteristic of Organic Semiconductor on Efficient Hole‐Transportation in Perovskite Device

AbstractIntrinsic characteristics of organic semiconductor‐based hole transport materials (HTMs) such as facile synthesizability, energy level tunability, and charge transport capability have been highlighted as crucial factors determining the performances of perovskite photovoltaic (PV) cells. However, their properties in the excited state have not been actively studied, although PVs are operated under solar illumination. Here, the characteristics of organic HTMs in their excited state such as transition dipole moment can be a decisive factor that can improve built‐in potential of PVs, consequently enhancing their charge extraction property as well as reducing carrier recombination. Moreover, the aggregation property of organic semiconductors, which has been an essential factor for high‐performance organic HTMs to improve their carrier transport property, can induce a synergistic effect with their excited state property for the high‐efficiency perovskite PVs. Additionally, it is also confirmed that their optical bandgaps, manipulated to have their absorption in the UV region, are beneficial to block UV light that degrades the quality of perovskite, consequently improving the stability of perovskite PV in p–i–n configuration. As a proof‐of‐concept, a model system, composed of triarylamine and imidazole‐based organic HTMs, is designed, and it is believed that this strategy paves a way toward high‐performance and stable perovskite PV devices.

Resolving Donor–Acceptor Interfaces and Charge Carrier Energy Levels of Organic Semiconductors with Polar Side Chains

AbstractOrganic semiconductors consisting of molecules bearing polar side chains have been proposed as potential candidates to overcome the limitations of organic photovoltaics owing to their enhanced dielectric constant. However, introducing such polar molecules in photovoltaic devices has not yet resulted in higher efficiencies. A microscopic understanding of the impact of polar side chains on electronic and structural properties of organic semiconductors is paramount to rationalize their effect. Here, the impact of such side chains on bulk heterojunction overall morphology, molecular configurations at donor–acceptor (DA) interfaces, and charge carrier energy levels is investigated. The multiscale modeling approach used allows to resolve DA interfaces with atomistic resolution while taking into account the large‐scale self‐organization process which takes place during the processing of an organic thin film. The polar fullerene‐based blends are compared to the well‐studied reference system, poly(3‐hexyl‐thiophene) (P3HT):phenyl‐C61‐butyric acid methyl ester (PCBM). Introduction of polar side chains on a similar molecular scaffold does not affect molecular orientations at the DA interfaces; such orientations are, however, found to be affected by processing conditions and polymer molecular weight. Polar side chains, instead, are found to impact considerably the charge carrier energy levels of the organic blend, causing electrostatic‐induced broadening of these levels.

Electroless‐Plated Gold Contacts for High‐Performance, Low Contact Resistance Organic Thin Film Transistors

AbstractDeposition of metallic electrodes on a semiconductor medium is an indispensable factor in governing carrier injection, and a metal/semiconductor contact that can be formed via solution process is highly desired in printed electronics. However, fine‐patterning the solution processes of metallic electrodes without damaging the excellent electronic properties of organic semiconductors (OSCs) is still a challenge. In this work, electroless plating, a metal coating technique that involves auto‐catalytic reaction in an aqueous solution, is used to fabricate top‐contact organic thin‐film transistors (OTFTs). An electroless‐plated gold pattern with a spatial resolution of 10 micrometers is transferred and laminated on a monolayer of OSCs to serve as a hole‐injection electrode. The fabricated OTFTs exhibit reasonably high field‐effect mobility of up to 13 cm2 V−1 s−1 and decent contact resistance as low as 120 Ω · cm, which implies that an ideal metal/semiconductor contact can be realized. This electroless plating technique can provide possibilities for practical mass production of organic integrated circuits because it is in principle cost‐effective, capable of covering large areas, high‐vacuum free, and environmentally friendly.

Electron Beam Induced Tailoring of Electrical Characteristics of Organic Semiconductor Films

Tailoring the characteristics of organic semiconductors including molecular semiconductor and conducting polymers is the frontline area of research for improving the performance of organic electronic devices. Electron beam treatment has been established as one of the easiest method in comparison to others like chemical doping, thermal processing, ozonolysis, UV and other ionizing radiation treatment, to tune the physico-chemical properties of organic semiconductors. High energy electron beam (EB) generated from an accelerators impinges energy to the material and causes several phenomena including doping, crosslinking, chain degradation, gas evolution, molecular structural modifications, oxidation and unsaturation. Such modifications lead to variation in electrical characteristics and consequently affect the overall device performances. In the present review we have focused on the different interaction processes of EB with organic semiconductors and its implications to tailor the performance of device comprising of it mainly gas sensors, field effect transistors, thermoelectric power generators and radiation dosimeters.

Tuning of Molecular Electrostatic Potential Enables Efficient Charge Transport in Crystalline Azaacenes: A Computational Study.

The chemical versatility of organic semiconductors provides nearly unlimited opportunities for tuning their electronic properties. However, despite decades of research, the relationship between molecular structure, molecular packing and charge mobility in these materials remains poorly understood. This reduces the search for high-mobility organic semiconductors to the inefficient trial-and-error approach. For clarifying the abovementioned relationship, investigations of the effect of small changes in the chemical structure on organic semiconductor properties are particularly important. In this study, we computationally address the impact of the substitution of C-H atom pairs by nitrogen atoms (N-substitution) on the molecular properties, molecular packing and charge mobility of crystalline oligoacenes. We observe that besides decreasing frontier molecular orbital levels, N-substitution dramatically alters molecular electrostatic potential, yielding pronounced electron-rich and electron-deficient areas. These changes in the molecular electrostatic potential strengthen face-to-face and edge-to-edge interactions in the corresponding crystals and result in the crossover from the herringbone packing motif to π-stacking. When the electron-rich and electron-deficient areas are large, sharply defined and, probably, have a certain symmetry, calculated charge mobility increases up to 3–4 cm2V−1s−1. The results obtained highlight the potential of azaacenes for application in organic electronic devices and are expected to facilitate the rational design of organic semiconductors for the steady improvement of organic electronics.

Selenium-containing core-expanded naphthalene diimides for high performance n-type organic semiconductors

The incorporation of heavy atoms into molecular backbone is an extremely straightforward strategy for fine-tuning the optoelectronic properties of organic semiconductors. However, it is rarely studied in n-type small molecules. Herein, by selenium substitution of NDI3HU-DTYM2, two Se-decorated core-expanded naphthalene diimides (NDI) derivatives DTYM-NDI3HU-DSYM ( 1 ) and NDI3HU-DSYM2 ( 2 ) were synthesized. In comparison with the reference S-containing compound NDI3HU-DTYM2, the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy levels of 1 and 2 were fine-tuned with ∆HOMO of about 0.2 eV, ∆LUMO of 0.1 eV and the narrowed HOMO-LUMO gaps. More surprisingly, the as-spun organic thin film transistors (OTFTs) based on 1 and 2 both showed µ e,sat values as high as 1.0 cm2 V−1 s−1, which are 2-fold higher than that of NDI3HU-DTYM2 with the same device structure and measurement conditions. In addition, the single crystal OFET devices based on Se-containing compound NDI2BO-DSYM2 showed a high µ e,sat value of 1.30 cm2 V−1 s−1. The molecular packing of NDI2BO-DSYM2 in single crystals (two-dimensional supramolecular structure formed by intermolecular Se···Se interactions) is quite different from that of a S-containing compound NDI-DTYM2 (one dimensional supramolecular structure formed by intermolecular π-π stacking). Therefore, the Se substitution can cause dramatic change about molecular stacking model, giving rise to high n-type OTFT performance. Our results demonstrated an effective strategy of the heavy atom effect for designing novel organic semiconductors.

Controlling Structure and Properties of Vapor-Deposited Glasses of Organic Semiconductors: Recent Advances and Challenges.

The past decade has seen great progress in manipulating the structure of vapor-deposited glasses of organic semiconductors. Upon varying the substrate temperature during deposition, glasses with a wide range of density and molecular orientation can be prepared from a given molecule. We review recent studies that show the structure of vapor-deposited glasses can be tuned to significantly improve the external quantum efficiency and lifetime of organic light-emitting diodes (OLEDs). We highlight the ability of molecular simulations to reproduce experimentally observed structures, setting the stage for in silico design of vapor-deposited glasses in the coming decade. Finally, we identify research opportunities for improving the properties of organic semiconductors by controlling the structure of vapor-deposited glasses.

Control over Kinetic and Thermodynamically Driven Pathways of Crystallization to Yield Cofacial and Slipped-Stack Dimers in Single Crystals.

Control over the molecular packing in the solid state is of utmost importance in regulating the bulk optical properties of organic semiconductors. The electronic coupling between the molecules makes it possible to improve the properties of the bulk materials. This work reports an example of control over the selective formation of polymorphic single crystals of donor-acceptor-type small-molecule compound 25TR by 1) kinetic or 2) thermodynamic course of crystallisation to yield slipped stack (S) and cofacial (C) dimers in the single crystals. The distinct optical characteristics of the C-dimer and S-dimer are summarised. Both forms show significant excitonic interactions in the solid state, and the S-dimeric form has strong yellowish orange fluorescence, whereas the C-dimeric form is non-fluorescent in the crystalline state. DFT calculations and differential scanning calorimetric experiments revealed that the C-dimer polymorph is the thermodynamically stable form with a free energy offset of 0.43 eV in comparison with the S-dimer. Interestingly, the thermodynamically driven non-fluorescent single crystal was found to be convertible to its fluorescent form irreversibly by thermal trigger. The charge-carrier-transport characteristics of these two polymorphs were computed by using the Marcus-Hush formalism. The computations of the charge-carrier-transport behaviour revealed that the S-dimer (25TR(R) ) is ambipolar, whereas the C-dimer (25TR(Y) ) is predominantly n-type.

Developing molecular-level models for organic field-effect transistors.

Organic field-effect transistors (OFETs) are not only functional devices but also represent an important tool for measuring the charge-transport properties of organic semiconductors (OSs). Thus, efforts to understand the performance and characteristics of OFET devices are not only useful in helping achieve higher device efficiencies but also critical to ensuring accuracy in the evaluations of OS charge mobilities. These studies rely on OFET device models, which connect the measured current characteristics to the properties of the OSs. Developing such OFET models requires good knowledge of the charge-transport processes in OSs. In device active layers, the OS thin films are either amorphous (e.g. in organic light-emitting diodes and organic solar cells) or crystalline (e.g. those optimized for charge transport in OFETs). When the electronic couplings between adjacent OS molecules or polymer chain segments are weak, the charge-transport mechanism is dominated by hopping processes, which is the context in which we frame the discussion in this Review. Factors such as disorder, mobility anisotropy, traps, grain boundaries or film morphology all impact charge transport. To take these features fully into account in an OFET device model requires considering a nano-scale, molecular-level resolution. Here, we discuss the recent development of such molecular-resolution OFET models based on a kinetic Monte Carlo approach relevant to the hopping regime. We also briefly describe the applicability of these models to high-mobility OFETs, where we underline the need to extend them to incorporate aspects related to charge delocalization.

An Organic Borate Salt with Superior p-Doping Capability for Organic Semiconductors.

Molecular doping allows enhancement and precise control of electrical properties of organic semiconductors, and is thus of central technological relevance for organic (opto‐) electronics. Beyond single‐component molecular electron acceptors and donors, organic salts have recently emerged as a promising class of dopants. However, the pertinent fundamental understanding of doping mechanisms and doping capabilities is limited. Here, the unique capabilities of the salt consisting of a borinium cation (Mes2B+; Mes: mesitylene) and the tetrakis(penta‐fluorophenyl)borate anion [B(C6F5)4]− is demonstrated as p‐type dopant for polymer semiconductors. With a range of experimental methods, the doping mechanism is identified to comprise electron transfer from the polymer to Mes2B+, and the positive charge on the polymer is stabilized by [B(C6F5)4]−. Notably, the former salt cation leaves during processing and is not present in films. The anion [B(C6F5)4]− even enables the stabilization of polarons and bipolarons in poly(3‐hexylthiophene), not yet achieved with other molecular dopants. From doping studies with high ionization energy polymer semiconductors, the effective electron affinity of Mes2B+[B(C6F5)4]− is estimated to be an impressive 5.9 eV. This significantly extends the parameter space for doping of polymer semiconductors.

Structure and Doping Optimization of IDT-Based Copolymers for Thermoelectrics.

π-conjugated backbones play a fundamental role in determining the thermoelectric (TE) properties of organic semiconductors. Understanding the relationship between the structure–property–function can help us screen valuable materials. In this study, we designed and synthesized a series of conjugated copolymers (P1, P2, and P3) based on an indacenodithiophene (IDT) building block. A copolymer (P3) with an alternating donor–acceptor (D-A) structure exhibits a narrower band gap and higher carrier mobility, which may be due to the D-A structure that helps reduce the charge carrier transport obstacles. In the end, its power factor reaches 4.91 μW m−1 K−2 at room temperature after doping, which is superior to those of non-D-A IDT-based copolymers (P1 and P2). These results indicate that moderate adjustment of the polymer backbone is an effective way to improve the TE properties of copolymers.

Toward Efficient All-Polymer Solar Cells via Halogenation on Polymer Acceptors.

Although halogenation has been widely regarded as an effective approach to adjust the properties of organic semiconductors, systematic investigation on the comparison of nonhalogenated and halogenated polymer acceptors only received minor attention in all-polymer solar cell (all-PSC) community. Herein, we report three IDIC-based narrow band gap polymer acceptors, PIDIC2T, PIDIC2T2F, and PIDIC2T2Cl, which are composed of IDIC-C16 building blocks as acceptor units, linking pristine bithiophene, fluorinated bithiophene, or chlorinated bithiophene as donor units. Although these three polymer acceptors exhibit nearly identical lowest unoccupied molecular orbital (LUMO) levels of ca. -3.87 eV with a similar optical band gap of ca. 1.54 eV, we found that different halogen species significantly affect the electron mobility and thin-film morphology of the polymer acceptors. All-PSCs were fabricated by pairing three polymer acceptors with a PBDB-T polymer donor, while PIDIC2T2Cl delivered a highest power conversion efficiency (PCE) of 5.34% due to its favorable bulk morphology with smaller root-mean-square (rms) roughness values, which induce the relatively more balanced charge carrier mobilities. By blending the fluorinated analogue of PBDB-T, PM6, further improved VOC, JSC, and fill factor (FF) of devices were achieved (5.46% for PM6:PIDIC2T, 4.96% for PM6:PIDIC2T2F, 7.11% for PM6:PIDIC2T2Cl), which can be due to the synergistic effect of the deeper highest occupied molecular orbital (HOMO) energy level of PM6, enhanced crystallinity, and more matched charge transport. This systematic study provides an insight into the influence of halogenation (fluorination and chlorination) on the optoelectrical properties of n-type organic semiconductors and demonstrates an efficient strategy that the design guideline for polymer acceptors can be enriched by backbone halogenation to further develop high-performance all-PSCs.

A Three-Dimensional Porous Organic Semiconductor Based on Fully sp2 -Hybridized Graphitic Polymer.

Dimensionality plays an important role in the charge transport properties of organic semiconductors. Although three‐dimensional semiconductors, such as Si, are common in inorganic materials, imparting electrical conductivity to covalent three‐dimensional organic polymers is challenging. Now, the synthesis of a three‐dimensional π‐conjugated porous organic polymer (3D p‐POP) using catalyst‐free Diels–Alder cycloaddition polymerization followed by acid‐promoted aromatization is presented. With a surface area of 801 m2 g−1, full conjugation throughout the carbon backbone, and an electrical conductivity of 6(2)×10−4 S cm−1 upon treatment with I2 vapor, the 3D p‐POP is the first member of a new class of permanently porous 3D organic semiconductors.

A Three‐Dimensional Porous Organic Semiconductor Based on Fully sp2‐Hybridized Graphitic Polymer

AbstractDimensionality plays an important role in the charge transport properties of organic semiconductors. Although three‐dimensional semiconductors, such as Si, are common in inorganic materials, imparting electrical conductivity to covalent three‐dimensional organic polymers is challenging. Now, the synthesis of a three‐dimensional π‐conjugated porous organic polymer (3D p‐POP) using catalyst‐free Diels–Alder cycloaddition polymerization followed by acid‐promoted aromatization is presented. With a surface area of 801 m2 g−1, full conjugation throughout the carbon backbone, and an electrical conductivity of 6(2)×10−4 S cm−1 upon treatment with I2 vapor, the 3D p‐POP is the first member of a new class of permanently porous 3D organic semiconductors.