Semitransparent Organic Solar Cells Research Articles

Achieving bifacial photovoltaic performance in PTB7-based organic solar cell by integrating transparent contact for emerging semi-transparent applications

In this study, the design, fabrication and detailed analysis of semi-transparent bifacial organic solar cells (ST-OSC) based on MoO3/Ag/WO3 (10/dm/dod nm) dielectric/metal/dielectric (DMD) transparent contact system integrated with PTB7 polymer were investigated. The study emphasizes the importance of designing transparent contact systems to optimize the solar cells’ transparency (average visible transmittance, AVT), color rendering (color rendering index, CRI), efficiency (power conversion efficiency, PCE), and bifaciality. The performance of three distinct configurations was examined in the AVTmax (47.14% AVT, 3.93% PCE), (CRIext)max (23.82% AVT, 6.21% PCE), and Extreme Color (26.34% AVT, 5.81% PCE). The theoretically predicted AVTs for these configurations were 48.75%, 22.29%, and 25.15%, respectively. The strong agreement between theoretical and observed outcomes confirmed the accuracy of the Transfer Matrix Model (TMM). Furthermore, the assessment of bifaciality performance exhibited that the AVTmax had a bifaciality factor of 0.94, with a PCE of 3.67% under top illumination and 3.93% under bottom illumination. The high bifaciality of the structure designed with TMM to maximize the AVT demonstrates the value of calculations prior to solar cell structure fabricating and the possibility of constructing high bifaciality structures using this technique.

Tunable optical and photovoltaic performance in PTB7-based colored semi-transparent organic solar cells integrated MgF2/WO3 1D-photonic crystals via advanced light management.

This study explores the design, fabrication, and characterization of PTB7-based colored semi-transparent organic solar cells (ST-OSCs) with integrated MgF2/WO3 one-dimensional photonic crystals (1D-PCs). Integrating 1D-PCs enhanced light management by creating tunable photonic band gaps, leading to extraordinary color change and improved photon harvesting. For 1DPC5 - 425 the Average Visible Transmittance (AVT) values were 33.3%, and CIE x, y was 0.43, 0.52, for 1DPC3 - 650 AVT were 25.09% and CIE x, y was 0.23, 0.27, respectively. Thus, extraordinary color changes from blue to yellow could be achieved while keeping transparency. Thereupon, photovoltaic performance showed notable improvements, with Jsc increasing from 7.98mA/cm2 to 9.95mA/cm2 and 10.45mA/cm2 for 1DPC5 - 425 and 1DPC3 - 650, respectively. By 1D-PC integration, power conversion efficiency (PCE) reached from 3.93 to 4.90% and 5.08% for 1DPC5 - 425 and 1DPC3 - 650, respectively. The Color Rendering Index (CRI) indicated successful color tuning and acceptable rendering, with CRI of 52 and 87. The study demonstrates that 1D-PC integration significantly enhances ST-OSCs' optical and photovoltaic properties, paving the way for advanced energy-harvesting applications.

Advancing Multifunctional Semitransparent Organic Solar Cells through Strategic Optical Layer Integration

Advancing Multifunctional Semitransparent Organic Solar Cells through Strategic Optical Layer Integration

High-performance semi-transparent organic solar cells for window applications using MoO3/Ag/MoO3 transparent anodes

The optimization of semi-transparent organic solar cells involves balancing average visible transparency (AVT) and power conversion efficiency (PCE). We propose enhancing ST-OSC performance by replacing the conventional opaque Ag electrode with a MoO3/Ag/MoO3 as a dielectric/metal/dielectric (DMD) layer structure, explored theoretically and experimentally. A prototype ST-OSC configuration, comprising ITO/ZnO/P3HT: PCBM/MoO3/Ag/MoO3, was fabricated with varying thicknesses of the MoO3/Ag/MoO3 layer, determined through theoretical calculations utilizing MATLAB software. This study investigates the impact of metal layer thickness on two active layer densities (10 and 18 mg/mL) and evaluates AVT, color rendering index, Correlated Color Temperature, and CIELAB color coordinates (a*, b*). Both theoretical calculations and experimental results confirm that the optimized configuration of the DMD structure with specific layer thicknesses for each component (MoO3 = 10nm/Ag = 6nm/MoO3 = 30 nm) achieves an AVT of over 59.60 %. This high level of transparency makes this configuration suitable for applications requiring both high transparency and efficient light transmission. The optimized device delivered high-quality light transmission, approaching white perception to the human eye. This combined approach validates empirical results and provides a deeper understanding of transparent OSC mechanisms.

Material and Application of Semitransparent Organic Solar Cells

Material and Application of Semitransparent Organic Solar Cells

Optimization Light Utilization Efficiency of Semitransparent Organic Solar Cells by Regulating Absorption Spectrum

Optimization Light Utilization Efficiency of Semitransparent Organic Solar Cells by Regulating Absorption Spectrum

N-Doping Donor-Dilute Semitransparent Organic Solar Cells to Weaken Donor: Acceptor Miscibility and Consolidate Donor-Phase Continuity.

Lightweight and semi-transparent organic solar cells (ST-OSCs) offer bright promise for applications such as building integrated photovoltaics. Diluting donor content in bulk-heterojunction active layers to allow greater visible light transmittance (AVT) effectively enhances device transparency, yet the ineluctable compromise of the donor-phase continuity is challenging for efficient charge transport. Herein, a trace amount of n-type N-DMBI dopant is incorporated, which facilitates the donor:acceptor (D:A) de-mixing by strengthening both acceptor polarity and D/A crystallization. With the diminution of component inter-mixing, the limited number of donors increasingly self-aggregate to establish the more continuous phases. For the benchmark PM6:Y6-based ST-OSCs, when the donor content is reduced from regular 45 to optimal 30 wt.%, the device AVT is remarkably raised by more than a quarter, accompanied by a marginal drop in power conversion efficiency from 13.89% to 13.03%. This study reveals that by decreasing the donor content to <30 wt%, acceptor excitons induced by Förster resonance energy transfer are prone to severe radiative recombination. This is nonetheless mitigated by dopant inclusion within the acceptor phase by providing extra energy offset and prolonging charge transfer state lifetime to assist exciton dissociation.

A novel optical management layer with flexible color tunability and high transmittance in organic solar cells

The evaluation of colored semi-transparent organic solar cells (ST-OSCs) relies on the power conversion efficiency (PCE) and peak transmittance across the visible light spectrum. However, it is a significant challenge to enhance both parameters simultaneously. In this study, we investigate the impact of different film systems for the Ag electrode on transmittance enhancement using an optical interference formula derived for anti-reflective films. As a result, a novel ZnS/WO3 double-layer anti-reflective film is introduced as an optical management layer. The ZnS/WO3/Ag structure achieves a peak transmittance exceeding 75 % across the visible light spectrum while also offering customizable color attributes. Upon electrical simulation, the power conversion efficiency (PCE) of organic solar cells with 15 nm Ag and 80 nm PM6:Y6 reached to 11.72 %, and an ideal PCE value of 14.53 % is achieved by reducing non-radiative recombination. Through optical simulations, it has been demonstrated that the integration of a ZnS/WO3 double-layer anti-reflective film with organic solar cells enables the generation of OSCs in vibrant purple, blue, cyan, and green hues. Notably, these OSCs exhibit their highest peak transmittance at blue light (452.5 nm), reaching an impressive value of 50.49 %. These remarkable findings not only showcase exceptional performance but also highlight significant potential in applications involving colored OSCs utilizing the new optical management layer composed of ZnS/WO3 double-layer anti-reflective films.

Semitransparent organic solar cells with high light utilization efficiency and color rendering index

Semitransparent organic solar cells with high light utilization efficiency and color rendering index

Improved performance of ternary organic solar cells based on both bulk and pseudo-planar heterojunction active layer

The high photovoltaic conversion efficiency (PCE) of ternary organic solar cells (OSCs) based on PTB7-Th, PC71BM and IEICO-4F material is obtained, the short-circuit current density (J SC), fill factor (FF), and open-circuit voltage is 25.90 mA cm−2, 73.20% and 0.71 V, respectively. PCE is as high as 13.53%. It is the highest PCE of ternary OSCs based on PTB7-Th, PC71BM and IEICO-4F materials for all we know. The narrow bandgap material of IEICO-4F is deposited on PTB7-Th:PC71BM bulk heterojunction (BHJ) by layer-by-layer process. We constructed the dual bandgap active layer both BHJ and pseudo-planar heterojunction (P-PHJ), it could be defined as ternary BHJ/P-PHJ of OSCs. This type of OSCs is not only the complementary bandgap material of the active layer, but also increasing the donor/acceptor (D/A) interface. The excitons generation and collection of the device are increased leading a higher J SC and FF. The semitransparent OSCs (ST-OSCs) is prepared by varying the thickness of Ag electrode and PCE can reach 9.70%, and the average visible light transmittance and light use efficiency of ST-OSCs are improved effectively.

Optically Enhanced Semitransparent Organic Solar Cells with Light Utilization Efficiency Surpassing 5.5%

AbstractConverting non‐visual light into photocurrent while maintaining high visual transparency is vital for semitransparent organic solar cells (ST‐OSCs) application, yet often challenging over insufficient invisible light‐harvesting. Herein, spectrally selective optical manipulation for ST‐OSCs with high visual light transparency and full‐spectral non‐visual light reflection is proposed by matching the optical admittance of ultrathin Ag films using ZnS and MgF2. The reflection of optically enhanced ST‐OSCs at the spectral region beyond the human eye's response spectrum is improved and the transmission in the visual region is simultaneously enhanced. By further integrating an anti‐reflective structure, the optimal structure boosts the average visible transmittance and power conversion efficiency of ST‐OSCs to 44.3% and 12.6%, respectively, yielding a record light utilization efficiency of 5.6%. Corresponding flexible ST‐OSCs with high mechanical stability implies that this work provides a facile and universal strategy for ST‐OSCs aiming at building integrated photovoltaics.

Recent Progress in Semitransparent Organic Solar Cells: Photoabsorbent Materials and Design Strategies.

The increasing energy demands of the global community can be met with solar energy. Solution-processed organic solar cells have seen great progress in power conversion efficiencies (PCEs). Semitransparent organic solar cells (ST-OSCs) have made enormous progress in recent years and have been considered one of the most promising solar cell technologies for applications in building-integrated windows, agricultural greenhouses, and wearable energy resources. Therefore, through the synergistic efforts of transparent electrodes, engineering in near-infrared photoabsorbent materials, and device engineering, high-performance ST-OSCs have developed, and PCE and average visible transmittance reach over 10% and 40%, respectively. In this review, we present the recent progress in photoabsorbent material engineering and strategies for enhancing the performance of ST-OSCs to help researchers gain a better understanding of structure-property-performance relationships. To conclude, new design concepts in material engineering and outlook are proposed to facilitate the further development of high-performance ST-OSCs.

The Role of Device Architecture and Interfacial Layer on Performance of Semitransparent Organic Solar Cells

Semitransparent organic solar cells (ST‐OSCs) generally suffer from voltage loss in comparison to their opaque counterparts. Herein, ST‐OSCs constructed with conventional and inverted structures have been explored. The voltage losses of the inverted ST‐OSCs are lower than that of the conventional architectures when the thicknesses of the top transparent electrodes approach the percolation threshold, which is attributed to the larger surface energy of the bottom seeding layers, higher built‐in electric fields, and lower recombination losses. Moreover, ST‐OSCs with conventional architectures based on four commonly used electrode transporting layers (ETLs) PDINN, PDINO, PNDIT‐F3N, and PFN‐Br are employed to distinguish the Voc variation when capping with 10 nm top electrodes. It is revealed that ETL with larger surface energy and a stronger ability to reduce the cathode work function is more beneficial for reducing the voltage loss for ST‐OSCs. This work demonstrates the crucial role of device structure and interfacial layers in optimizing the ST‐OSC device performance.

Identifying and Amplifying the Spontaneously Formed Photo‐Charge Contribution in Opaque and Semitransparent Organic Photovoltaics

AbstractSpontaneous photo‐charge (SP) generation within the non‐fullerene (NFA) bulk helps avoid exciton (EX) related loss as compared to the traditional heterojunction route in organic solar cells (OSCs). Unfortunately, the promising SP utilization attracts little attention at this time due to the lack of knowledge on its specific contribution to the photovoltaic performance and rational optimization in high‐efficiency devices. To fill the gap, the NFAs’ SP characteristics are related with their photocurrent loss and power conversion efficiency (PCE) in state‐of‐the‐art materials. Though higher SP population is good for efficient EX utilization, it simultaneously acts as an additional photo‐charge recombination channel. The former can be further enhanced by increasing the NFAs’ crystallinity with preferred lamellar growth, and the latter can be suppressed via electric doping. With the aid of the two‐step optimization strategy, the total photocurrent loss is reduced from 14.4% to 4.8%, accompanying with PCE increment from 16.9% to 18.5%. The SP utilization strategy is finally applied in the semitransparent OSCs (ST‐OSCs), due to its less heterojunction area sensitive photo‐charge generation characteristic. A light utilization efficiency (LUE) is then increased from 3.21% to 3.77%. The findings highlight the pursue of efficient SP utilization as a new design philosophy in future OSCs’ progresses.

Dithienopyran-based narrow-bandgap donor polymers: Unveiling the potential for semitransparent organic solar cells with enhanced NIR absorption

Semitransparent organic solar cells (ST-OSCs) have recently received considerable attention in the field of photovoltaics owing to their great potential in applications such as building-integrated photovoltaics, self-powered greenhouses, and vehicle coatings. Because the near-infrared (NIR) region is an invisible region whose photon content is higher than that of the visible region, it is preferable to apply photoactive materials with narrow bandgaps in ST-OSCs. Tremendous efforts have been made to develop narrow-bandgap non-fullerene acceptors, however, donor polymers with NIR absorption ability for efficient ST-OSCs have rarely been reported. In this study, two novel narrow-bandgap donor polymers, PDTP-TBT and PDTTP-TBT, are designed and synthesized. Both polymers exhibit strong NIR absorption and high transmittance in the visible region, suggesting their potential for use in ST-OSCs. An opaque OSC with a PDTTP-TBT-based photoactive layer achieves a higher power conversion efficiency (PCE) of 8.87% than a PDTP-TBT-based OSC (PCE of 3.65%) due to its better charge transport characteristics. Furthermore, an ST-OSC using PDTTP-TBT-based blend film exhibits a PCE of 6.72%, average visible transmittance of 43.9%, and light utilization efficiency of 2.95%.

Solid Additive Dual-Regulates Spectral Response Enabling High-Performance Semitransparent Organic Solar Cells.

Semi-transparent organic solar cells (ST-OSCs) possess significant potential for applications in vehicles and buildings due to their distinctive visual transparency. Conventional device engineering strategies are typically used to optimize photon selection and utilization at the expense of power conversion efficiency (PCE); moreover, the fixed spectral utilization range always imposes an unsatisfactory upper limit to its light utilization efficiency (LUE). Herein, a novel solid additive named1,3-diphenoxybenzene (DB) is employed to dual-regulate donor/acceptor molecular aggregation and crystallinity, which effectively broadens the spectral response of ST-OSCsin near-infrared region. Besides, more visible light is allowed to pass through the devices, which enables ST-OSCs to possess satisfactory photocurrent and high average visible transmittance (AVT) simultaneously. Consequently, the optimal ST-OSC based on PP2+DB/BTP-eC9+DB achieves a superior LUE of 4.77%, representing the highest value within AVT range of 40-50%, which also correlates with the formation of multi-scale phase-separated morphology. Such results indicate that the ST-OSCs can simultaneously meet the requirements for minimum commercial efficiency and plant photosynthesis when integrated with the roofs of agricultural greenhouses. This work emphasizes the significance of additives to tune the spectral response in ST-OSCs, and charts the way for organic photovoltaics in economically sustainable agricultural development.

All-solution-processed flexible semitransparent organic solar cells based on sprayed silver nanowire composites as top electrodes

Solution processable transparent top electrodes with good conductivity and high transmittance play a critical role in developing highly efficient semitransparent organic solar cells (ST-OSCs). Herein, a simple low-temperature spray-coating method is proposed to fabricate silver nanowires/zinc oxide nanoparticles (AgNWs/ZnO) composite electrodes. The effects of coverage of ZnO nanoparticles on optoelectronic properties and surface morphologies of the composites are systemically investigated. Compared to the pristine AgNWs, the AgNWs/ZnO composite layer exhibits improved electrical conductivity due to the filling of nanoparticles as well as the capillary force caused during the volatilization of ZnO dispersion. A low sheet resistance of 8.3 Ω/ and a high transmittance of 78.91 % at 550 nm are achieved in the optimized AgNWs/ZnO composite films with excellent thermal and mechanical stabilities. By using the spray-coated AgNWs composite as the top electrode, the PM6:N3 based ST-OSCs prepared on ITO/glass substrate attain a power conversion efficiency (PCE) of 10.88 % and an average transmittance (AVT) of 28.80 % due to the enhanced charge extraction and suppressed trap-assisted recombination. Moreover, fully solution-processed ST-OSCs are fabricated based on AgNWs/ZnO top electrodes, achieving a PCE of 9.01 % and an AVT of 27.8 %. It provides a simple and effective strategy to fabricate transparent flexible top electrodes and may pave the way towards all-solution-processed highly efficient ST-OSCs.

Novel Materials for Semi-Transparent Organic Solar Cells

The rapid development of photovoltaic technology has driven the search for novel materials that can improve the cost-effectiveness and efficiency of solar cells. Organic semiconductors offer unique optical tunability and transparency, allowing customization for the absorption of specific optical spectra like near-infrared radiation. Through the molecular engineering of electron donors and acceptors, these materials can be optimized for targeted optical selectivity. This adaptability enables the development of efficient energy-harvesting devices tailored for specific spectral regions. Consequently, organic semiconductors present a promising avenue for specialized applications such as semi-transparent organic solar cells. This review offers a detailed summary of the latest developments in novel organic semiconductor materials, focusing on design principles and synthesis of materials in the context of semi-transparent organic solar cells. Optimization of molecular architecture, photovoltaic performance, and the optoelectronic properties of these materials has been explored, highlighting their potential for next-generation solar energy conversion.

Human-friendly semitransparent organic solar cells achieving high performance

We systematically evaluated the photobiological safety of mainstream ST-PV devices and fabricated a series of high-performance human-friendly ST-PV devices with LUE values exceeding 5.0% and low skin/eye damage levels for human beings.

Collaborative regulation strategy of donor and acceptor analogues realizes multifunctional semitransparent organic solar cells with excellent comprehensive performance

We propose a collaborative regulation strategy of donor and acceptor analogues to develop multi-functional ST-OSCs with highly comprehensive performance.