Organic Solar Cell Devices Research Articles

An Approach Towards Low Energy Loss by End-capped Modification of A2–D–A1–D–A2-type Molecules for Tuning the Photovoltaic Properties of Organic Solar Cells

In this project, the study is focused on the substitution at determined sites of reference molecule (R) to enhance optoelectronic properties, which might affect the photovoltaic performance of organic solar cells. Herein, seven new molecules (M1 to M7) were designed by the modification of the terminal acceptors. The density functional theory was employed to explore optoelectronic properties. Majority of the molecules own exceptional optical properties than reference molecule, for instance, narrow bandgap, low excitation energy, lower binding energies, better oscillator strength and progressive light harvesting efficiency. The density of state, frontier molecular orbitals and transition density matrix diagrams indicated that the charge density transfer occurs from donor to acceptor. Moreover, charge transfer investigations of designed molecules with PTB7-Th complex were performed by analyzing the concentration of charge transfer over molecular orbitals, i.e., highest occupied to lowest unoccupied molecular orbitals. Thus, these computed molecules may be employed to develop efficient organic solar cell devices with promising photovoltaic prospects in the near future.

Low‐Cost Pentacyclic Nonfullerene Acceptors to Exceed 13% Efficiency by Thermal Annealing‐Free Treatment

Nonfullerene electron acceptors (NFAs) improve the photoelectrical conversion efficiency of organic solar cells (OSCs), but they suffer from high synthetic cost and time‐consuming thermal annealing treatment. Nevertheless, low‐cost NFAs and simple device fabrication are still crucial issues to boosting the commercial application of OSCs. Herein, one kind of low‐cost pentacyclic NFAs based on benzothiadiazole and thiophene derivatives named L1‐EH and L1‐BO with different substitutions is successfully synthesized and characterized. The optimized OSCs based on PM6:L1‐BO (2‐butyloctyl side chain) display an outstanding power conversion efficiency of 13.15%. Moreover, OSC devices based on these acceptors operate in thermal annealing‐free conditions. Further studies manifest that the proper side chains in NFAs can induce more favorable face‐on molecule orientation, enhance carrier mobility, balance charge transport, and reduce recombination losses. This research demonstrates that these types of low‐cost NFAs are promising active layer candidates of high‐efficiency organic solar cells featuring simple device manufacture.

Electronic structure and photophysical properties of some promising organic molecules for organic solar cells.

Three novel organic semiconductors (Fig. 1), which are molecule (a) and molecule (c) have the same wing unit molecules (b) and (c) have the same core unit were reported. Thus, the influence of wing units on solar cell device performance parameters such us the opto-electronics properties, non-linear optics (NLO), electronic properties, and natural bond orbitals (NBO) were calculated in order to evincing molecular structure-property relations. The all studied molecules would be promising materials for photovoltaic applications, but molecule (c) could be an excellent candidate for high efficiency organic solar cells with a small energy gap, a lowest ΔGreg, highest Voc, and LHE values. According to all these results, it is seen that the wing units of the molecules affect both the opto-electronic properties and NLO properties more than the core units. These theoretical calculations is expected to obtain new strategies to synthesize efficient materials for organic solar cell devices. Density functional (DFT) and time-dependent density functional (TDDFT) theory simulations for the solar cell device performance parameters, non-linear optics, and natural bond analysis were performed using the Gaussian 09w software. The ground state properties of molecules have been studied with hybrid functional of Beckethree-Lee-Yang-Parr (B3LYP), and excited state properties have been calculated CAMB3LYP and our DFT calculations were performed using 6-31++G(d,p) basis set on fully optimized geometries.

In Silico Design of Freeform Solar Cell Structures from High‐Throughput Artificial Intelligence‐Generated Configurations

Recent advances in artificial intelligence‐generated configurations (AIGC) have transformed various fields in science and technology domains and enabled the inverse design of materials and structures for enhanced performance with minimal human input. The patterned micro‐/nanostructures are widely adopted to increase power conversion efficiencies in thin‐film organic solar cells (OSCs), making these structures highly suitable for AIGC applications. Although the computational cost of traditional numerical simulations is a barrier to making AIGC high throughput, this issue is addressed by integrating the high‐speed automated machine learning (AutoML) Analyzer with genetic algorithm‐based topology optimization algorithms. Compared to standard numerical solutions, the AutoML Analyzer in the proposed system predicts outcomes ≈22 700 times faster, resulting in a 98.47% reduction in computation costs, while maintaining high average accuracies of ≈99%. By evaluating an extensive dataset of 600 000 AIGCs, an optimized PM6:Y6 OSC device design with a power conversion efficiency of 17.58% is identified, significantly outperforming the 14.70% baseline efficiency of the OSC device without the poly methyl methacrylate scattering and substrate layers. Results underscore the potential of AIGC techniques for efficiently enhancing the performance of photovoltaic devices in renewable energy applications.

An empirical analysis of ZnO/Ag nanocomposites thin film organic solar cell with optical and structural properties

For organic solar cells (OSCs), a novel polymer donor (PMMA) and a new small molecule acceptor (Ag NPs) were devised and produced. The effects of the donor and acceptor on the absorption spectra, molecular energy levels, and charge mobilities were thoroughly investigated. The results showed that the PMMA/ZnO/Ag NPs OSCs exhibited a high power conversion efficiency of 5.7%, which is attributed to the complementary absorption spectra, matched energy levels, and efficient charge transport. These findings suggest that PMMA and Ag NPs are promising materials for the development of high-performance OSCs. The PMMA-based OSC device demonstrated with a thickness of 200–300 nm achieving an efficiency of over 5.7%, indicating the promise of photovoltaic OSCs in practical applications. The findings were used to regulate nanomorphology and ultimately improve solar cell performance.

Efficient Multilayers Organic Solar Cells with Hybrid Interfacial Layer-based P3HT and CuO Nanoparticles

Organic solar cell (OSC) devices suffer from low power conversion efficiency (PCE) due to deep trap states that absorb photogenerated charges, act as recombination centers, and reduce charge collection. To further improve the PCE, an optimized hole transport layer (HTL) must be engineered for efficient hole transport and reduced deep trap states. A hybrid HTL consisting of organic and inorganic materials was formed using a combination of CuO nanoparticles (NPs) having an average size of 50 nm and poly(3-hexylthiophene) (P3HT). The hybrid HTL was used in the fabrication and characterization of an inverted OSC device structure. In consequence, the incorporation of CuO-NPs into the P3HT resulted in an increase of 8.66% in photocurrent density. Additionally, the PCE increased from 3.77 to 4.22% while the open circuit voltage (Voc) was maintained. The higher hole mobility obtained for the optimum device using the charge extraction by increasing voltage (CELIV) measurement was 8.47 × 10− 4 cm2 V− 1 s− 1. This highlights the potential of designing novel organic solar cells with inorganic nanoparticles, offering enhanced performance and efficiency.

Dynamic Metastable Characteristics of Carbon Cages Embedded with Er2C2.

Novel endohedral metallofullerenes (EMFs), namely, Er2C2@C2v(5)-C80, Er2C2@Cs(6)-C82, Er2C2@Cs(15)-C84, Er2C2@C2v(9)-C86, Er2C2@Cs(15)-C86, and Er2C2@Cs(32)-C88, had been experimentally synthesized, and the unique structures and many fascinating properties had also been widely explored. Nevertheless, the position of the Er atoms inside the cage shows a severe disorder within the stable EMF monomer, which is difficult to understand and explain from the experimental point of view. In this work, based on the density functional theoretical calculations, the Er2C2@Cs(6)-C82 has 73 directional isomers and 2 Er atoms that are far beyond from Er-Er single bonding and tend to be close to the cage side (marked as "shell"), and the core (Er2C2 units) takes on a butterfly shape as generally revealed. The energy difference between any two of the isomers is in the range of 0.05 to 25.6 kcal/mol, indicating a relatively easy thermodynamic transition between the isomers. The other five Er carbide cluster EMFs (Er2C2@C2v(5)-C80, Er2C2@Cs(15)-C84, Er2C2@C2v(9)-C86, Er2C2@Cs(15)-C86, and Er2C2@Cs(32)-C88) are also studied in the same way, and 30, 37, 39, and 43 most stable Er-oriented sites inside the cage, respectively, are obtained. In addition, the shape of the Er2C2 gradually changed from butterfly to linear. Moreover, the electronic structure and molecular orbital analyses show that it is easy for Er2C2@C80-88 to form a charge transfer state of [Er2C2]4+@[C80-88]4- via the dynamic core-shell coordination equilibrium. Er2C2 with a steep drop in chemical stability is restricted to forming varying degrees of metastable states in the shell, determined by the shell size, to ensure the overall stability. The lowest unoccupied molecular orbital energy level of these EMFs is increased by 0.5-1.1 eV compared with fullerenes C80-88, potentially providing favorable conditions for suitable energy level matching with EMF as an electron acceptor used in organic solar cell devices.

Role of 9-phenyl-9H-carbazole based hole transport materials for organic and perovskite photovoltaics

The present study has focused on designing and characterizing ten novel (SS1-SS10) hole transport materials (HTM) for perovskite solar cells (PSCs). The objective is to enhance power conversion efficiency (PCE) and improve these devices' durability. A systematic investigation has been carried-out to investigaye the optoelectronic properties of these HTMs. Density functional theory (DFT) and time-dependent density functional theory (TD-DFT) have been employed to analyze the structures and optical features of these designed HTMs. The calculations included the arrangement of frontier molecular orbitals (FMO), open-circuit voltages (Voc), the density of states (DOS), transition density matrix (TDM), power conversion efficiency (PCE), reorganizational energies of electrons and holes, charge transfer analysis, and molecular electrostatic potential (MEP). Newly designed molecules (SS1-SS10) exhibit promising optoelectronic features with narrower energy gap (ranges from 1.41 eV to 0.64 eV) and absorbed maximum absorption wavelength (546 nm) compared to the reference molecule which have a gap of 3.41 eV and wavelength of 414.88 nm. The designed molecules also have high open-circuit-voltage values of 0.92–1.08 and proficient hole and electron transport abilities making them strong candidates when blended with the polymer PC70BM. The computed value of R for λe is 0.0082. The lowest reorganisation energy for electrons appears in SS8, SS3, and SS5, showing strong charge mobility within the acceptor and donor sections. The reorganisation energy of hole (λh) for R was discovered to be 0.0060, among all the designed molecules SS6 has the highest λh value. The study highlights that efficient molecular design and strategy are necessary for developing desirable photovoltaic precursors best suited for perovskite organic solar cells. The modeled materials SS1-SS10 are recommended for future synthesis and development of cost-effective organic solar cell devices.

Designing of novel organic semiconductors materials for organic solar cells: A machine learning assisted proficient pipeline

Typical research design associated with organic solar cells (OSCs) is conventionally considered time-consuming and laborious because the selection of the materials as the core, pi-acceptor, and terminal groups required for the engineering of these devices is done via hit and trial methodology. The advanced data-driven approaches, particularly machine learning (ML), have materialized as the robust technique for identifying the organic materials for the fabrication of the OSCs devices. The key parameters of highest occupied molecular orbital (HOMO), lowest unoccupied molecular orbital (LUMO), and maximum absorption wavelength (λmax) were selected for developing the ML models. The molecular descriptor associated with each parameter was investigated and the relative contribution of the understudy descriptors in the training of the ML model was studied by using the relative importance test. The Hist gradient boosting (HGB) model exhibited the best results for performing the predictive analysis of all three parameters. Moreover, the chemical database was constructed based on the academic literature to develop the high-performance OSCs devices, and the trained HGB model was applied to predict the HOMO, LUMO, and λmax values for these newly designed OSCs devices. Synthetic accessibility of designed molecules is also predicted which revealed that the suggested new organic molecules can be easily commercialized via experimentation. Highly encouraging results in terms of the understudy key parameters were acquired by this ML approach indicating that the data-driven approaches hold extreme potential for engineering high-performance OSCs devices.

Multifunctional Narrow Band Gap Terpolymer-Enabled High-Performance Dopant-Free Perovskite and Additive-Free Organic Solar Cells with Long-Term Stability.

The optoelectronic devices endowing multifunctionality while utilizing a single low-cost material have always been challenging. For this purpose, we adopted a random ternary copolymerization strategy for designing two terpolymers, namely TP-0.8-EG and TP-0.8-TEG comprising a benzothiadiazole (BT)-benzo[1,2-b:4,5-b']dithiophene-diketopyrrolo[3,4-c]pyrrole (A1-π-D-π-A2) backbone. The figure of merits of the narrow band gap TP-0.8-EG terpolymer include deepened frontier energy levels, high hole mobility, better film formability, enriched multifunctionality, and passivation capability. Accordingly, the suitable electronic properties of TP-0.8-EG revealed that it can function as a dopant-free hole-transporting material in perovskite solar cells (PSCs) as well as the third component in organic solar cells (OSCs). Remarkably, TP-0.8-EG outperforms by exhibiting a higher power conversion efficiency (PCE) of 20.9% over TP-0.8-TEG (PCE of 18.3%) and BT-UF (PCE of 14.6%) in dopant-free PSCs. Interestingly, TP-0.8-EG fabricated along with PM6:Y7 displayed a high PCE of 16.52% in ternary OSCs. Also, TP-0.8-EG established good device storage stabilities (85 and 83% of their initial PCEs for 1200 and 500 h) in dopant-free PSC as well as OSC devices. Notably, the devices with TP-0.8-EG showed excellent thermal and moisture stabilities. To the best of our knowledge, A1-π-D-π-A2 terpolymer performing both in PSCs and OSCs with decent efficiencies and good device stabilities is a rare scenario.

Polythiophene-based terpolymers with modulated aggregation behaviors for high-performance organic solar cells with 16.6% efficiency

Polythiophenes (PTs) are an attractive class of polymer donors (PDs) for organic solar cells (OSCs) owing to their relatively simple structures and scalable synthesis. Herein, a series of chlorinated thiazole-incorporated PT terpolymers are designed and high-performance OSCs with a power conversion efficiency (PCE) of 16.6% are demonstrated. By incorporating two different units, 3,3′-difluoro-2,2′-bithiophene (T2F2) and thieno[3,2-b]thiophene (TT), the aggregation properties of the terpolymers (PTz-FX; X = 0, 30, 50, 70, and 100, where X represents the mole percentage of T2F2 to total T2F2 +TT) are modulated. Among the PTz-FX series, PTz-F70 is found to be the optimal PD because its suitably tuned aggregation property leads to an optimized blend morphology with well-developed crystalline structures and donor–acceptor intermixed domains. The balanced morphology not only promotes charge generation/transport but also suppresses charge recombination in OSC devices. Thus, the PTz-F70-based OSCs achieve the highest PCE (16.6%), outperforming the OSCs based on PTz-FX with extremely strong (PTz-F100, PCE = 14.7%) or weak (PTz-F0, PCE = 12.0%) aggregation properties. The PCE of the PTz-F70-based OSCs is one of the highest performances among PT-based binary OSCs. This study highlights the importance of controlling the aggregation property of PTs for achieving high-performance PT-based OSCs.

Two compatible non-fullerene acceptors towards efficient ternary organic photovoltaics

The composition of organic active layers plays significant role in determining the photovoltaic performance of organic solar cells (OSCs). Ternary strategy has shown promising advantages in fabrication for highly efficient OSCs due to its simple process and various donor and acceptor materials. Herein, a famous small molecule acceptor (ITIC) was employed as an assistant acceptor to make efficient ternary organic solar cells (TOSCs). The use of ITIC shows good compatibility and leads to the formation of alloyed state with the host acceptor (BTP-eC9). The middle bandgap of ITIC is also complementary with those of the host active materials (BTP-eC9 and PM6), which will be beneficial for the light-harvesting and thus enhance the photocurrent for OSC devices. Furthermore, the introduction of ITIC can fine-tune the film morphology with continuous nanofiber interpenetrating network, which is great for more balanced charge carrier transport and efficiently suppressed charge recombination. Consequently, a prominent power-conversion-efficiency (PCE) was achieved up to 18.25% with all-around enhancement photovoltaic parameters for the PM6:BTP-eC9:ITIC-based TOSCs.

Mitigating Coffee Ring Effects for Efficient Upscaling of Flexible Organic Solar Cells

As a roll‐to‐roll compatible technology, slot‐die coating has shown great potential for manufacturing industrial‐level organic solar cells (OSCs). However, in the slot‐die coatings process, coffee rings are often formed due to the slow film‐forming kinetics, leading to a significant loss of power conversion efficiency (PCE) in upscaling device area. Herein, the coffee rings are suppressed by introducing an airflow‐assisted slot‐die technique to obtain a suitable active layer morphology with improved flatness and homogeneity. Synergistically, optimization of airflow and substrate temperature conditions, the PCE of 1 cm2 flexible OSC devices reaches 13.69%. Moreover, large‐area flexible OSC modules with 30 cm2 achieve a PCE of 13.08%, maintaining 95% of 1 cm2 device, which is the minimum PCE loss from 1 cm2 to large‐area devices. Morphology characterization shows that airflow can suppress excessive molecular aggregation and obtain suitable phase separation. Therefore, this work provides an efficient method to fabricate high‐efficiency flexible large‐area OSC modules, which will promote OSC devices from lab to fab.

Flexible Memristive Organic Solar Cell Using Multilayer 2D Titanium Carbide MXene Electrodes.

Hybrid systems have attracted significant attention within the scientific community due to their multifunctionality, which has resulted in increasing demands for wearable electronics, green energy, and miniaturization. Furthermore, MXenes are promising two-dimensional materials that have been applied in various areas due to their unique properties. Herein, a flexible, transparent, and conductive electrode (FTCE) based on a multilayer hybrid MXene/Ag/MXene structure that can be applied to realize an inverted organic solar cell (OSC) with memory and learning functionalities is reported. This optimized FTCE exhibits high transmittance (84%), low sheet resistance (9.7 Ω sq-1 ), and reliable operation (even after 2000 bending cycles). Moreover, the OSC using this FTCE achieves a power conversion efficiency of 13.86% and sustained photovoltaic performance, even after hundreds of switching cycles. The fabricated memristive OSC (MemOSC) device also exhibits reliable resistive switching behavior at low operating voltages of 0.60 and -0.33V (similar to biological synapses), an excellent ON/OFF ratio (103 ), stable endurance performance (4 × 103 ), and memory retention properties (104 s). Moreover, the MemOSC device can mimic synaptic functionalities on a biological time scale. Thus, MXene can potentially be used as an electrode for highly efficient OSCs with memristive functions for future intelligent solar cell modules.

Efficient non-fullerene organic solar cells employing aqueous solution-processed MoO3 as a hole-transporting layer

Organic solar cell (OSC) has drawn considerable interest in recent decades owing to their advantages of light weight, flexible, large area and potentially low-cost. Employing an appropriate hole-transporting layer (HTL) into an OSC device has been proved as an efficient method to obtain high efficiency OSC due to the enhancement of the hole transporting and extraction of the device. In this work, aqueous solution-processed MoO3 (s-MoO3) thin films were employed as HTLs to construct non-fullerene PM6:Y6 OSCs. The s-MoO3 thin film was prepared by using an aqueous solution process from an isopolymolybdate [NH4]6Mo7O24.4H2O precursor followed by thermal annealing treatment to convert the precursor to MoO3. The s-MoO3 HTL based PM6:Y6 device demonstrates a power conversion efficiency of 15.75%, which is 38% improved than that of the device with thermally evaporated-MoO3 as HTL and 8% improved than that of the device with PEDOT:PSS as HTL. The enhancement of the device performance could be attributed to the enhanced hole mobility and better band matching of the s-MoO3 HTL. Moreover, the s-MoO3 HTL based PM6:Y6 device exhibited higher device stability than those of the reference devices. Our finding indicates that this s-MoO3 film has great potential as efficient HTL for high performance non fullerene OSCs.

Direct Arylation Synthesis of Small Molecular Acceptors for Organic Solar Cells.

In recent years, small molecular acceptors (SMAs) have extensively promoted the progress of organic solar cells (OSCs). The facile tuning of chemical structures affords SMAs excellent tunability of their absorption and energy levels, and it gives SMA-based OSCs slight energy loss, enabling OSCs to achieve high power conversion efficiencies (e.g., >18%). However, SMAs always suffer complicated chemical structures requiring multiple-step synthesis and cumbersome purification, which is unfavorable to the large-scale production of SMAs and OSC devices for industrialization. Direct arylation coupling reaction via aromatic C-H bonds activation allows for the synthesis of SMAs under mild conditions, and it simultaneously reduces synthetic steps, synthetic difficulty, and toxic by-products. This review provides an overview of the progress of SMA synthesis through direct arylation and summarizes the typical reaction conditions to highlight the field's challenges. Significantly, the impacts of direct arylation conditions on reaction activity and reaction yield of the different reactants' structures are discussed and highlighted. This review gives a comprehensive view of preparing SMAs by direct arylation reactions to cause attention to the facile and low-cost synthesis of photovoltaic materials for OSCs.

Layer‐by‐Layer‐Processed Organic Solar Cells with 18.02% Efficiency Enabled by Regulating the Aggregation of Bottom Polymers

The fabrication of organic solar cells (OSCs) by a layer‐by‐layer (LBL) method has attracted growing attention in recent years. As already known, the pre‐aggregates of conjugated polymers in solution have a profound impact on their microstructure morphology in films. Herein, by simply controlling the solution temperature and annealing processes, the pre‐aggregation behavior of D18 polymer in solution can be fine‐tuned and the microstructure of D18 bottom layer is well manipulated. The optimized D18 bottom layer can effectively regulate L8‐BO upper‐layer‐forming suitable networks for efficient charge transportation. In addition, a vertical phase separation with a special D/D:A/A structure (P‐i‐N‐type component distribution) is also formed. As a result, compared to the 16.43% power conversion efficiency (PCE) of the bulk heterojunction devices, such control enables bilayer OSC devices based on the polymer D18 and L8‐BO to deliver an enhanced PCE of 18.02% with simultaneously improved short‐circuit current density, open‐circuit voltage, and fill factor. It is also demonstrated in these results that the LBL deposition process utilizing the pre‐aggregation of polymer and its fiber‐network‐forming ability is a very promising approach to improve charge dynamics, suppress carrier recombination, and fabricate highly efficient OSCs.

Modulation of Dielectric Constant and Photovoltaic Properties of 2,1,3‐benzothiadiazole‐based Alternating Copolymers by Adding Fluorine Atoms to the Backbone of Polymers

AbstractIn organic solar cells (OSCs), fluorine (F) substitution of conjugated polymers has a variety of effects on molecular properties and device performance. In this work, three conjugated polymers, namely PBDT‐4F‐BTs, PBDT‐8F‐FBTs, and PBDT‐10F‐FBTs, with 4, 8 and 10 fluorine atoms in the backbone were prepared and characterized. The conjugated polymers PBDT‐4F‐BTs, PBDT‐8F‐FBTs and PBDT‐10F‐FBTs showed the same highest occupied molecular orbital (HOMO) energy levels of −5.58 eV, which did not decrease with the increasing number of F atoms in each repeat unit of polymers. As the number of fluorine atoms in each repeat unit of polymers in the backbone increases from 4 to 10, the dielectric constant (ϵr) increases from 4.5 to 6.2 at 1 kHz. The bimolecular compounding was suppressed by introducing F into the polymer backbone and influenced the device compounding kinetics of OSCs from the blend films of polymers paired with the phenyl‐C71‐butyric‐acid‐methyl ester (PC71BM). Thereby the fill factor (FF) and power conversion efficiency (PCE) of the OSCs devices have been improved, the fluorine atoms in each repeat unit of polymers backbone increased from 4 to 10, FF increased from 48.7 % to 70.0 %, and the corresponding PCE increased from 3.43 % to 6.46 %.

Pinning energies of organic semiconductors in high-efficiency organic solar cells

With the emergence of new materials for high-efficiency organic solar cells (OSCs), understanding and finetuning the interface energetics become increasingly important. Precise determination of the so-called pinning energies, one of the critical characteristics of the material to predict the energy level alignment (ELA) at either electrode/organic or organic/organic interfaces, are urgently needed for the new materials. Here, pinning energies of a wide variety of newly developed donors and non-fullerene acceptors (NFAs) are measured through ultraviolet photoelectron spectroscopy. The positive pinning energies of the studied donors and the negative pinning energies of NFAs are in the same energy range of 4.3−4.6 eV, which follows the design rules developed for fullerene-based OSCs. The ELA for metal/organic and inorganic/organic interfaces follows the predicted behavior for all of the materials studied. For organic–organic heterojunctions where both the donor and the NFA feature strong intramolecular charge transfer, the pinning energies often underestimate the experimentally obtained interface vacuum level shift, which has consequences for OSC device performance.

Outdoor Stability of Triplet Generating and Triplet Harvesting Materials; Pentacene and Tetracene Electron Donors Merged with Boron Subphthalocyanines as Electron Acceptors

Triplet harvesting is a useful property that could enhance the performance of solar cells if applied in the right framework. There are currently few functional examples of organic solar cells (OSCs) capable of triplet harvesting, but materials are already under development. The improved current density output has already been realized, but the viability of working devices needs to be confirmed to advance this technology further. Here, we find that the outdoor stability of encapsulated devices can be improved significantly if triplet harvesting is enabled between the donor and acceptor. We compared the stability of pentacene/BsubPcs (boron subphthalocyanines) devices simultaneously and controlled the triplet harvesting capability by adjusting the peripheral chlorination on the BsubPcs. Pentacene/Cl–Cl12BsubPc devices which also exhibited the best triplet harvesting ability for this study experienced the least amount of degradation, not only was the stability improved when compared to other pentacene/BsubPc devices but these devices also had the highest stability of any that were tested including other singlet and triplet harvesting devices. This is promising for both the singlet fission donors and triplet harvesting acceptors involved and for triplet harvesting as a mechanism in totality. During this study, we also confirmed that some materials such as tetracene have insufficient thermal stability in devices. We also studied the relevant stability of single nanolayers of these materials. For example, single layer tetracene films seemed relatively stable without encapsulation even in harsh aging conditions but when incorporated into encapsulated OSC devices, the performance decreased quickly. Additional data acquired regarding tetracene also showed that even in the absence of light, OSC device performance decreased rapidly at elevated temperatures and may indicate that a nanomorphological change occurs; unless the nanomorphology can be passivated, we can conclude that tetracene may be difficult to incorporate into OSCs in the future.