Application In Perovskite Solar Cells Research Articles

Development of Superior Nickel Oxide Layer for Boosted Hole‐Transport Performance in Perovskite Solar Cells

Although revolutionary power conversion efficiency progress has been realized for inverted perovskite solar cells (PSCs), the selection and optimization of the hole‐transporting materials (HTMs) are still crucial for fabricating high‐efficiency, stable, and low‐cost PSCs. Nickel oxide (NiOx) is widely used in the PSCs community for material design and modification. However, various NiOx synthesis processes lead to kinds of NiOx, and it is difficult to determine which NiOx is suitable for application in PSCs. Herein, two kinds of NiOx HTMs are synthesized using sol–gel processed and chemical‐calcination‐processed (CCP) routes for the preparation of PSCs. Based on the physical properties of two kinds of NiOx HTMs as well as the corresponding photovoltaic parameters of PSCs, it is demonstrated that superior NiOx HTMs is obtained by the CCP method with the following properties: high transmittance to ensure sufficient sunlight capture of perovskite, appropriate energy levels to promote hole extraction and transfer, high conductivity to support charge transfer, and a good wetting surface to boost perovskite spreading and film formation. Thus, in this study, the direction for the reasonable selection of HTMs is pointed out to prepare efficient PSCs.

Facile synthesis and optimization of graphene oxide reduction by annealing in hydrazine vapour in ambient air for potential application in perovskite solar cells

Graphene oxide (GO) was synthesized from graphite via a modified Hummer's method, followed by thermal and chemical reductions to produce reduced graphene oxide (RGO) samples at various temperatures. A suite of characterization techniques including Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray Spectroscopy (EDS), UV-Visible Spectroscopy, thermogravimetric analysis (TGA), X-ray diffraction (XRD), and Hall effect measurements were employed to assess the structural, morphological, optical, and electrical properties of the samples. FTIR analysis confirmed the successful functionalization of graphite to GO and subsequent reduction to reduced graphene oxide, with peak intensities decreasing as the reduction temperature increased. UV-visible spectroscopy of GO showed a maximum absorption at 235 nm which confirmed the synthesis of GO while the reduction revealed a notable red shift in absorption peaks with increasing annealing temperature, and that signified a reduction in bandgap. XRD analyses demonstrated the removal of oxygen functional groups. The X-ray diffraction (XRD) analysis of GO showed diffraction at 2θ = 10.74° which revealed a fully oxidized graphene oxide with oxygen-containing functional groups, and hence an increase in interlayer spacing (d002) from 3.341 Å (graphite) to 8.228 Å (GO). Upon reduction, there is a gradual decrease in d002 from 8.228 Å (GO) to 3.387 Å (HRGO300), suggesting the gradual removal of intercalated oxygen molecules, and hence the gradual restoration of sp2 hybridisation in graphene. The EDS analysis revealed an increase in the carbon-to-oxygen (C/O) ratio from 1.78 in GO to 2.75 in HRGO300 as the annealing temperature for the reduction process increased which further confirmed the removal of oxygen functional groups. The Hall effect data showed hole mobility of 4.634 x101 (GO), 4.831 x101 (HRGO200), and 5.462 x100 (HRGO300) with conductivities of 8.985 x10-5 (GO), 1.087 x100 (HRGO200) and 1.791 x101 1/Ω cm, suggesting an increase in conductivity as the annealing temperature increased as revealed in the EDS. Out of the three samples identified as hole transport materials, the sample HRGO300 with the highest C/O ratio of 2.75 has the highest conductivity, and hence most suitable for application as hole transport material in perovskite solar cell.

Interfacial Mass Diagnostics: Quantitative Perspective on Construction and Mechanism Understanding of Dye-Sensitized, Perovskite and Quantum Dots Solar Cells.

Dye-sensitized solar cells (DSSCs), quantum dot-sensitized solar cells (QDSSCs) and perovskite solar cells (PSCs) have attracted wide attention. DSSCs, QDSSCs and PSCs can be prepared by liquid phase or solid phase, which causes a certain range of interface micro-mass changes during preparation. In addition, the photoelectric conversion process occurring inside the device also inevitably causes interface micro-mass changes. Interpretation of these interface micro-mass changes can help to optimize the cell structure, improve the stability and performance repeatability of the device, as well as directly or indirectly infer, track and predict the internal photoelectric conversion mechanism of the device. Quartz crystal microbalance (QCM) is a powerful tool for studying surface mass changes, extending this technology to the fields of solar cells to directly obtain interface micro mass changes, which makes the research more in-depth and opens up a new perspective for explaining the basic principles of solar cells. This review summarizes the research progress of QCM application in DSSCs, QDSSCs and PSCs in recent years, and explores the challenges and new opportunities of QCM application in new solar cells in the future.

Mass scale synthesis of graphene nanosheets using waste cardboard for application in perovskite solar cells and supercapacitors

Advanced graphene-based materials have been proficiently incorporated into next-generation solar cells and supercapacitors because of their high electrical conductivity, large surface area, excellent charge-transport ability, and exceptional optical properties. Herein, we report the synthesis of graphene nanosheets (GNs) from waste cardboard via pyrolysis, with ethyl alcohol as the growth initiator. Additionally, we demonstrated the use of GNs in energy conversion and storage applications. Using the GN electrode in perovskite solar cells resulted in an excellent power conversion efficiency of ∼10.41 % for an active area of 1 cm2, indicating an enhancement of approximately 27 % compared to conventional electrodes. Furthermore, the GNs were used as active electrode materials in supercapacitors with excellent electrochemical performance and a high gravimetric specific capacitance of 167.5 F/g at a scan rate of 2 mV/s. The developed GNs can be efficiently used for energy storage, conversion, and electrochemical sensing applications.

Durable Perovskite Solar Cells with 24.5% Average Efficiency: The Role of Rigid Conjugated Core in Molecular Semiconductors.

Efficient and robust n-i-p perovskite solar cells necessitate superior organic hole-transport materials with both mechanical and electronic prowess. Deciphering the structure-property relationship of these materials is crucial for practical perovskite solar cell applications. Through direct arylation, two high glass transition temperature molecular semiconductors, DBC-ETPA (202°C) and TPE-ETPA (180°C) are synthesized, using dibenzo[g,p]chrysene (DBC) and 1,1,2,2-tetraphenylethene (TPE) tetrabromides with triphenylene-ethylenedioxythiophene-dimethoxytriphenylamine (ETPA). In comparison to spiro-OMeTAD, both semiconductors exhibit shallower HOMO energy levels, resulting in increased hole densities (generated by air oxidation doping) and accelerated hole extraction from photoexcited perovskite. Experimental and theoretical studies highlight the more rigid DBC core, enhancing hole mobility due to reduced reorganization energy and lower energy disorder. Importantly, DBC-ETPA possesses a higher cohesive energy density, leading to lower ion diffusion coefficients and higher Young's moduli. Leveraging these attributes, DBC-ETPA is employed as the primary hole-transport layer component, yielding perovskite solar cells with an average efficiency of 24.5%, surpassing spiro-OMeTAD reference cells (24.0%). Furthermore, DBC-ETPA-based cells exhibit superior operational stability and 85°C thermal storage stability.

Air-Stable and Eco-Friendly Symmetrical Imine with Thiadiazole Moieties in Neutral and Protonated form for Perovskite Photovoltaics.

This paper proposes molecular and supramolecular concepts for potential application in perovskite solar cells. New air-stable symmetrical imine, with thiadiazole moieties PPL2: (5E,6E)-N2,N5-bis(4-(diphenylamino)benzylidene)-1,3,4-thiadiazole-2,5-diamine), as a hole-transporting material was synthesised in a single-step reaction, starting with commercially available and relatively inexpensive reagents, resulting in a reduction in the cost of the final product compared to Spiro-OMeTAD. Moreover, camphorsulfonic acid (CSA) in both enantiomeric forms was used to change the HOMO-LUMO levels and electric properties of the investigated imine-forming complexes. Electric, optical, thermal, and structural studies of the imine and its complexes with CSA were carried out to characterise the new material. Imine and imine/CSA complexes were also characterised in depth by the proton Nuclear Magnetic Resonance 1H NMR method. The position of nitrogen in the thidiazole ring influences the basicity of donor centres, which results in protonation in the imine bond. Simple devices of ITO/imine (with or without CSA(-) or CSA(+))/Ag/ITO architecture were constructed, and a thermographic camera was used to find the defects in the created devices. Electric behaviour was also studied to demonstrate conductivity properties under the forward current. Finally, the electrical properties of imine and its protonated form with CSA were compared with Spiro-OMeTAD. In general, the analysis of thermal images showed a very similar response of the samples to the applied potential in terms of the homogeneity of the formed organic layer. The TGA analysis showed that the investigated imine exhibits good thermal stability in air and argon atmospheres.

Spin-coated high mobility MoO3 thin film for designing highly efficient lead-free perovskite solar cells

Among the thin film-photovoltaics, perovskite solar cells (PSCs) are one of the most developing topics of research in recent times. Research records reveal that around 26 % efficiency in PSCs has already been achieved so far. However, the commercialization of those PSCs is hindered due to the toxicity of lead (Pb), and the instability of organic cations as well as structural volatility. Several inorganic materials including inorganic hole transport layer (HTL) have recently been proposed and developed to reduce the organic part in the device structure. We fabricate MoO3 thin film materials and conduct a detailed study to realize the potential of MoO3 as a unique HTL for application in PSCs. The synthesis of MoO3 thin film includes several characterization techniques e.g. XRD, FESEM, EDX, UV–Vis, and Hall Effect measurement. We design a MoO3 thin film-based, lead-free PSC structure of FTO/MoO3/PTAA/(FA)2BiCuI6/ZnO/Ag and perform numerical analysis using the SCAPS-1D simulation tool. In the device simulation process, we use the experimentally obtained optoelectrical properties of the MoO3 film and achieve a maximum efficiency of around 22.28 % in a contained lead-free PSC.

Highly Stable Perovskite Solar Cells with Protective Layers Obtained via Interfacial Modification

Currently, achieving both high efficiency and long‐term stability is crucial for the successful application of perovskite solar cells (PSCs). Grain boundary (GB) defects significantly impact the stability of PSCs, and passivating these GBs remains a major challenge. Herein, the surfactant dodecyltrimethylammonium chloride (DTAC) is dissolved in low‐polarity chlorobenzene (CB) at 58 °C to modify the interface of MAPbI3 film, and DTAC reacts with MAPbI3 film surface to generate a protective layer that can be covered on the perovskite grains, effectively reducing the expose GBs. Additionally, the hydrophobic alkyl chains of DTA+ and the strong chemical bond between the Cl− and Pb2+ ions further enhance the resistance of the perovskite surface layer to heat, moisture, and oxidation. Due to the passivation of iodine vacancy defects, the photo‐stability of unencapsulated DTAC devices is significantly improved. By passivating surface and GBs defects of the MAPbI3 perovskite crystals, the power conversion efficiency of the low‐temperature carbon‐based PSCs treated by DTAC is 15.03% compared to 13.97% for the control device. This study offers another referable strategy for enhancing the thermal, moisture, light, and oxygen stability of perovskite materials while considering the photovoltaic performance of devices.

Uncovering chemical structure-dependency of ionic liquids as additives for efficient and durable perovskite photovoltaics

Ionic liquids (ILs) have garnered significant attention in the field of perovskite solar cells (PSCs) due to their versatile capabilities in manipulating the crystallization kinetics, optimizing the morphology, and effectively passivating defects, leading to high-efficiency and long-term stability. While previous studies have mostly focused on individual ILs or different anions and their application in PSCs, the distinctive distribution of cations and anions within ILs underscores the significance of optimizing cationic structures and elucidates the particular role of cations in ILs on device performance. In this work, the implications of juxtaposing ILs incorporating carboxyl-functionalized imidazolium cations against conventional imidazolium-based counterparts on the crystallization kinetics, perovskite film quality, and the photovoltaic performance of perovskite devices. This strategy involving carboxyl-functionalized cations in ILs with a higher affinity to coordinate Pb2+, supported by chemical spectroscopy testing and a quantitative measure of the bond strength via Crystal orbital Hamiltonian group (COHP) calculations. The modified ILs more prominently results in enhancing the degree of PbI2 conversion into perovskite, slowing down crystallization rates and inducting formation of higher-quality perovskite films. Benefitting from the strong chemical interaction provided carboxyl-functionalized cations and widespread distribution of carboxyl-functionalized cations throughout the perovskite films, accomplishing comprehensive synergistic passivation of defects in perovskite films. This led to the suppression of non-radiative recombination and enhanced carrier transport properties. The incorporation of carboxyl modified ILs with suitable chemical structures resulted in a remarkable enhancement of the champion power conversion efficiency (PCE) to 24.21% in the ILs-treated device, coupled with excellent long-term stability.

A Universal and Versatile Hole Transport Layer “Activator” Enables Stable Perovskite Solar Cells with Efficiency Near 25%

AbstractOrganic small molecules have been proven to be the most efficient and predominantly employed hole transport layers (HTLs) in perovskite solar cells (PSCs), the reliance of HTLs on additives like Li‐TFSI has been unavoidable, particularly in terms of the well‐known Spiro‐OMeTAD. However, Li‐TFSI aggregation in HTL results in the decreased performance and stability of PSCs with serious hysteresis. It is an urgent need to explore a universal strategy to solve Li‐TFSI‐induced issues. Herein, a pyrene‐based organic semiconductor (PC) as an effective and universal additive for HTL application is developed. It is found that the introduction of PC can efficiently improve the hot carriers extraction/transfer and reduce the charge recombination in the device. Consequently, PSCs based on Spiro‐OMeTAD+PC as a HTL exhibit an excellent PCE of 24.80% with a negligible hysteresis, much higher than the control device (22.14%). Additionally, the efficiency of the PC incorporated into another well‐known X60 HTL‐treated device is enhanced to 24.12% from the control device (22.04%), confirming its universal application in PSCs. Moreover, PC can effectively suppress the Li+ aggregation in HTL, and the unencapsulated PSCs exhibit high stability. The findings in this work provide an effective and universal avenue to construct highly efficient and stable PSCs.

All-Inorganic Perovskite Solar Cells: Defect Regulation and Emerging Applications in Extreme Environments.

All-inorganic perovskite solar cells (PSCs), such as CsPbX3 , have garnered considerable attention recently, as they exhibit superior thermodynamic and optoelectronic stabilities compared to the organic-inorganic hybrid PSCs. However, the power conversion efficiency (PCE) of CsPbX3 PSCs is generally lower than that of organic-inorganic hybrid PSCs, as they contain higher defect densities at the interface and within the perovskite light-absorbing layers, resulting in higher non-radiative recombination and voltage loss. Consequently, defect regulation has been adopted as an important strategy to improve device performance and stability. This review aims to comprehensively summarize recent progresses on the defect regulation in CsPbX3 PSCs, as well as their cutting-edge applications in extreme scenarios. The underlying fundamental mechanisms leading to the defect formation in the crystal structure of CsPbX3 PSCs are firstly discussed, and an overview of literature-adopted defect regulation strategies in the context of interface, internal, and surface engineering is provided. Cutting-edge applications of CsPbX3 PSCs in extreme environments such as outer space and underwater situations are highlighted. Finally, a summary and outlook are presented on future directions for achieving higher efficiencies and superior stability in CsPbX3 PSCs.

The addition of fluorine atoms and alkyl chains to aromatic ligand dipole for enhancing stability and photoelectronic properties of formamidinium perovskite surfaces

The long-term stability on perovskite surfaces limits the practical application of perovskite solar cells (PSCs). Adding multifunction ligand can deal with this issue, however, the structure diversity of ligand and perovskite surface leads to the complicated adsorptive interaction, affecting the improvement effect of the stability and photoelectric properties. In this work, strongly electronegative fluorine atoms and alkyl chain with different length are introduced into aromatic ligand dipole to modify the polarity, regulating the phase stability, energy state and photoelectric properties of formamidinium perovskite (FAPbI3) surfaces. The results show the adsorption and interaction energy of positive ligand dipoles on the I-terminated surface decrease with the increase of polarity, which displays stronger ordered π-π stack and adsorption anchoring of ligand dipoles and thus decreasing the formation energy to improve the phase stability. The positive 4-Trifluoromethyl-phenethylammonium (CF3-PEA) with the highest polarity obtains the highest stability and shifts work function (WF) upward from 6.21 eV to the highest 6.46 eV. The negative CF3-PEA adsorbs on the PbI2-terminated surface induced by CF3•••Pb and π•••I interaction, achieving the stable phase with lower formation energy and lowest WF 5.61 eV. This work provides tutorial for optimizing performance of PSCs by the addition of ligand dipoles.

Defect Passivation Refinement in Perovskite Photovoltaics: Achieving Efficiency over 45% under Low-Light and Low-Temperature Dual Extreme Conditions.

Perovskite photovoltaics have emerged as the most promising candidates for next-generation light-to-electricity technology. However, their practical application still suffers from energy loss induced by intrinsic defects within the perovskite lattice. Here, a refined defect passivation in perovskite films is designed, which shows a multi-interaction mechanism between the perovskite and passivator. Interestingly, a shift of molecular bonding is observed upon cooling down the film, leading to a stronger passivation of iodine/formamidine vacancies. Such mechanism on device under low-light and low-temperature conditions is further leveraged and a record efficiency over 45% with durable ambient stability (T90 > 4000h) is obtained. The pioneer application of perovskite solar cells in above dual extreme conditions in this work reveals the key principles of designing functional groups for the passivators, and also demonstrates the capability of perovskites for diverse terrestrial energy conversion applications in demanding environments such as polar regions and outer space.

Printing PEDOT:PSS optimized using Response surface method (RSM) and genetic algorithm (ga) via modified 3D printer for perovskite solar cell applications

Despite significant improvements in solar cell fabrication processes, there are still significant challenges in the fabrication technology owing to poor production efficiency, large equipment and preparatory costs, substrate dependencies, material limitation, etc. This research proposes the use of a modified extrusion-based three-dimensional (3D) printing technology to print thin films of PEDOT:PSS (Poly 3,4-ethylenedioxythiophene:poly styrene sulfonate) for perovskite solar cell (PSC) applications and beyond. The main objective of the research is to induce the benefits of 3D printing technology into thin film printing for PSC applications. The central composite design (CCD) of the response surface method (RSM) in design expert software (Design Expert V13) and a genetic algorithm (GA) in MATLAB software are used to design and optimize the experiment, respectively. Accordingly, a uniformly thin PEDOT:PSS film with a 115 nm thickness is printed with the modified 3D printer at a print speed of 82 mm/s, a bed temperature of 80 °C, and an extrusion start position of 160 mm with a 0.1 mm inner diameter blunt needle and a 0.25 mm x-distance offset. To validate the printed PEDOT:PSS film for PSC application, other PSC layers, except for aluminum electrodes, are spin-coated on top of the 3D-printed PEDOT:PSS film, and the PSC is tested for its performance using a solar simulator. From the test, a competitive open-circuit voltage of 860 mV was produced. In general, printing PSC layers by modifying a cheap and easily available 3D printer has the benefits of excellent material utilization, substrate independence, rapid design, manufacture, and testing of solar cells in the electronic industry.

Nanostructured TiO2 thin films sputtered at room temperature as electron transport layer for flexible perovskite solar cell applications: Impact of varying RF power

This work examines the adoption of radio frequency (RF) sputtering at power ranging from 100 to 300 W to deposit nanostructured titanium dioxide (TiO2) thin films on indium tin oxide (ITO)-coated polyethylene terephthalate (PET) flexible substrate (ITO/PET) at room temperature. At higher RF power, X-ray diffraction (XRD) results exhibited evolution from amorphous into crystalline anatase with preferred (101) orientation and the films revealed spherical-like nanostructures with increasing grain size from 15.71 to 21.57 nm. Films transparency decreased from 79% to 70%. Estimated energy gap decreased from 3.57 to 3.36 eV, while refractive index increased from 2.19 to 2.25, denoting a red shift in the films. The thin film deposited at 300 W exhibited high conductivity and mobility of 19.65 × 10−5 Ω−1 cm−1 and 0.30 cm2/Vs, respectively. The film demonstrated its capability as an electron transport layer for flexible perovskite solar cells.

Improve the Charge Carrier Transporting in Two-Dimensional Ruddlesden-Popper Perovskite Solar Cells.

Conventional 3D organic-inorganic halide perovskite materials have shown substantial potential in the field of optoelectronics, enabling the power conversation efficiency of solar cells beyond 26%. A key challenge limiting the further commercial application of 3D perovskite solar cells is their inherent instability over outer oxygen, humidity, light, and heat. By contrast, 2D Ruddlesden-Popper (2DRP) perovskites with bulky organic cations can effectively stabilize the inorganic slabs, yielding excellent environmental stability. However, the efficiencies of 2DRP perovskite solar cells are much lower than those of the 3D counterparts due to poor charge carrier transporting property of insulating bulky organic cations. Their inner structural, dielectric, optical, and excitonic properties remain to be primarily studied. In this review, the main reasons for the low efficiency of 2DRP perovskite solar cells are first analyzed. Next, a detailed description of various strategies for improving the charge carrier transporting of 2DRP perovskites is provided, such as bandgap regulation, perovskite crystal phase orientation and distribution, energy level matching, interfacial modification, etc. Finally, a summary is given, and the possible future research directions and methods to achieve high-efficiency and stable 2DRP perovskite solar cells are rationalized.

Organic-inorganic hybrid material for hole transport in inverted perovskite solar cells.

Hole mobility is critical to the power conversion efficiencies of perovskite solar cells (PSCs). Organic small-molecule hole-transporting materials (HTMs) have attracted considerable interest in PSCs due to their structural flexibility and operational durability, but they suffer from modest hole mobility. On the other hand, inorganic HTMs with good hole mobility are inflexible in structural variation and exhibit unsatisfactory cell efficiency. In this study, a ligand BT28 and its zinc-based coordination complex BTZ30 were synthesized, characterized, and investigated as HTMs for PSC applications. The mixed-halide perovskites can be grown uniformly with large crystalline grains on both HTMs, which exhibit similar optical and electrochemical properties. However, it was discovered that the BTZ30-based solar cell exhibited an open-circuit voltage of 1.0817 V and a high short-circuit current density of 23.1392 mA cm-2 with a champion power conversion efficiency of close to 20 %. The performance difference between the two HTMs can be attributed to the difference in their hole mobilities, which is 63.31 % higher for BTZ30 than BT28. The comparison of non-metal and metal HTMs revealed the importance of considering hybrid structures to overcome some shortcomings associated with organic and inorganic HTMs and achieve high-performance PSCs.

Multi-Functional Spirobifluorene Phosphonate Based Exciplex Interface Enables Voc Reaching 95% of Theoretical Limit for Perovskite Solar Cells.

Metal halide perovskite solar cells (PSCs) show significant advancements in power conversion efficiency (PCE). However, the open-circuit voltage (VOC) of PSCs is limited by interfacial factors such as defect-induced recombination, energy band mismatch, and non-intimate interface contact. Here, an exciplex interface is first developed based on the strategically designed and synthesized two spirobifluorene phosphonate molecules to mitigate VOC loss in PSCs. The exciplex interface constructed by the intimate contact between the multi-functional molecules and hole transport layer takes the roles to promote the hole extraction by donor-acceptor interaction, passivate coordination-unsaturated Pb2+ defects by equipped phosphonate groups, and optimize the energy level alignment. As a result, a record VOC of 1.26V with a perovskite bandgap of 1.61eV is achieved, representing over 95% of theoretical limit. This advancement leads to an increase in PCE from 21.29% to 24.12% and improved stability. The exciplex interface paves the way for addressing the long-standing challenge of VOC loss and promotes the wider application of PSCs.

Recent Advances in Poly(3‐hexylthiophene) and Its Applications in Perovskite Solar Cells

2,2',7,7'‐Tetrakis(N,N‐di‐p‐methoxyphenylamine)‐9,9'‐spirobifluorene (Spiro‐OMeTAD) is considered the backbone of high performance in perovskite solar cells (PSCs) with the highest recorded power conversion efficiency near 26%. Devices with Spiro‐OMeTAD as a hole‐transport material (HTM) inherit very low stability due to the use of ionic‐based and unstable hygroscopic dopants to boost their hole mobility, hindering their stability. Poly(3‐hexylthiophene) (P3HT) is considered one of the promising HTM candidates, due to its formidable physical and electronic properties including higher hole mobility and thermal and moisture‐resisting nature. Despite these advantages, pristine P3HT‐based PSCs suffer low photovoltaic performances owing to unmatched perovskite/hole‐transport layer (HTL) interface and low mobility compared to doped HTMs. Today, studies are focusing on how to manage the interface between perovskite and P3HT and improve its hole mobility to achieve significant performance records in n–i–p PSCs. Herein, the advances of P3HT HTL are reviewed and light is shed on its different related approaches. Doping strategies and structural and molecular modifications to boost the hole mobility are reviewed. Interface engineering approaches to enhance the contact between perovskite and P3HT are discussed in detail. Moreover, incorporation in future PSC applications is investigated. Finally, a summary and a short outlook are provided.

Theoretical investigation of triphenylamine/anthradithiophene based systems as potential organic hole transport materials for perovskite solar cells

Hole transport materials (HTMs) are important constituents in perovskite solar cell fabrication. In this work structure property relationship of five different HTMs based on triphenylamine/anthradithiophene systems are investigated using DFT method. The orientation of the attachment of the thiophene rings on the anthracene core of anthradithiophene system has significant effect on the electronic and optical properties of the HTMs. The results are compared with the well-known HTMs. The predicted hole mobility of the molecules are found to be similar order of magnitude as that of spiro-OMeTAD. Thus, these HTMs can be potential replacements for spiro-OMeTAD in perovskite solar cell applications.