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Perovskite photovoltaics (PePVs) tend to suffer from a high density of defects that restricts the device in terms of -performances and -stability. Therefore, defect passivation and film-quality imp...

Materials used on a building’s exterior must have high transmittance and excellent aesthetic design. In this study, the optimum design was achieved by calculating the optical properties and color distribution to fabricate a high-quality multilayer color thin film through sputtering, and a silicon solar panel was equipped with transmissive- and reflective-type color optical thin films. A three-layer color thin film with a Nb2O5/SiO2/Nb2O5 structure exhibited an average transmittance of over 85.96% and a clear blue color. Simultaneously, it maintained a high overall efficiency with a maximum output value greater than 99% of the value of a reference silicon solar cell. Therefore, the sputtered multilayer thin-film coating not only offers a fracile approach to manufacture colorful solar panels, but also has great potential for various industrial applications such as building-integrated solar power generation, automobile production, and glass production.

To find promising device architecture for air-stable as well as efficient semitransparent perovskite solar cells (PeSCs), Ag & Cu semitransparent top electrode and interfacial engineering technologies are explored in PeSCs consisting with indium tin oxide (ITO)/hole transporting layer (HTL)/CH3NH3PbI3/[6,6]-phenyl-C61 butyric acid methyl ester (PCBM)/Ag or Cu. Devices with NiOx HTL exhibits better performance than conventional poly (3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) based devices and modification of PCBM with polyethylenimine ethoxylated (PEIE) also induces improved performance. Optimized semitransparent PeSC with Cu shows superior performance, achieving a power conversion efficiency (PCE) of 11.95% and average visible transmittance (AVT) of ∼20%, and stability to Ag based device.

In parallel with soaring efficiency, interest in multi-functional semitransparent perovskite solar cells (PeSCs) has emerged for special applications such as windows and tandem cells. To demonstrate air-stable as well as efficient ITO-free semitransparent PeSCs, ultra thin Cu and Ni, which are well-known non-precious metals having sufficient electrical conductivity, are investigated as bottom transparent electrode and optimization of devices is systematically carried out. Semitransparent Ni/NiOX based PeSC exhibits the average visible transmittance (AVT) of 22% and power conversion efficiency (PCE) of 8.20%. Considering required AVT for the application of power-generating window of ∼25% and recent reports, this result is one of the best performances reported to date.

Recently, the incorporation of passivation agents to reduce perovskite recombination has been proven to be one of the best approaches to achieving high-performance perovskite solar cells (PeSCs). Although several passivation compounds have been discovered, the mechanisms of passivation in diverse functional groups remain a mystery. In this work, we design bi-functional passivation agents, including methyl and carboxyl groups, as well as multi-functional passivation agent structures, including both methyl and carboxyl groups, and then we systematically study their passivation- and crystallinity control-abilities for PeSCs. Through electrostatic interactions with perovskite precursors, bi-functional passivation agents combined with piperidine ring and methyl (CH3) can passivate defects, and the carboxyl group (C = O) can increase the grain size and reduce the grain boundaries. Importantly, different functional groups, such as COCH3 groups comprising piperidine rings, CH3, and C = O, further improved the defect passivation effect. As the interaction between Pb2+ and COCH3 increased, the slow nuclear growth process of perovskite films introducing COCH3 increased the film quality and their charge extraction/collection capability, thus resulting in a PCE of 19.67%. In addition, the COCH3-based PesC's VOC and long-term stability are substantially enhanced.

To demonstrate efficient and reliable indium thin oxide (ITO)-free organic solar cells (OSCs), we fabricated highly conductive poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) electrodes by two-step brush-painting of PEDOT:PSS and dimethyl sulfoxide (DMSO). While one-step brush-painted electrodes with PEDOT:PSS and DMSO mixed solution showed large deviation in morphology and efficiency, uniform and highly conductive PEDOT:PSS electrodes were obtained by successive brush-painting of PEDOT:PSS and DMSO, respectively. ITO-free OSC exhibiting power conversion efficiency (PCE) of 3.74% was successfully demonstrated by optimized successive brush-painting.

In this data article, we introduced the hysteresis of planar perovskite solar cells (PSCs) fabricated using dimethylformamide (DMF), gamma-butyrolactone (GBL), methyl-2-pyrrolidinone (NMP), dimethylsulfoxide (DMSO), DMF-DMSO, GBL-DMSO and NMP-DMSO as perovskite precursor solutions according to different scan directions, sweep times, and current stability. The hysteresis analyses of the planar PSCs prepared with a glass-ITO /NiOX/perovskite /PC61BM/BCP/Ag configuration were measured with Keithley 2400 source meter unit under 100 mW/cm2 (AM 1.5 G). The data collected in this article compares the hysteresis of PSCs with different solvents and is directly related to our research article “High-Performance Planar Perovskite Solar Cells: Influence of Solvent upon Performance” (You-Hyun Seo et al., 2017 [1] ).

We systemically studied the influence of various precursor solvents on perovskite films and their effects on solar cell performances in p-i-n planar-structured perovskite solar cells (PSCs). For comprehensive and reasonable consideration to achieve a better solvent selection, various solvents such as dimethylformamide (DMF), gamma-butyrolactone (GBL), methyl-2-pyrrolidinone (NMP), dimethyl sulfoxide (DMSO), DMF-DMSO, GBL-DMSO, and NMP-DMSO that were well known as the most representative and effective solvent for perovskite precursor solvents were chosen, and they were all investigated and compared comprehensively on the basis of cell performances, quantum efficiencies, charge transport behaviors, intermediate-phase formation, and perovskite film morphology. These comparative investigations revealed that the DMF-DMSO can raise the device performances in planar-structured perovskite devices more largely than other solvents. More notably, an excellent power conversion efficiency of 15.05% with no distinct hysteresis was produced from the PSCs with DMF-DMSO. This approach will be a meaningful step toward a better solvent design for the realization of better-performing planar perovskite solar devices.

Although highly conductive poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) has emerged as alternative transparent electrodes to indium thin oxide (ITO), cell-performance is inferior to ITO based polymer solar cells (PSCs). To improve PEDOT:PSS based PSCs, we inserts metal-oxide hole transport layer (HTL) between PEDOT:PSS electrodes and photoactive layers for the first time. Device with optimized vanadium oxide HTL exhibits enhanced power conversion efficiency (PCE) of 3.33% (3.03% for conventional ITO-free PSCs). Improved performance is attributed to the increased shunt resistance and reduced surface roughness of PEDOT:PSS electrodes. Furthermore, improvement in device-stability under the atmospheric condition is observed.

In this research, we demonstrate that a solution-processable reduced graphene oxide/poly (N-vinylpyrrolidone) nanocomposite (rGO/PVP) can be easily obtained by a scalable and cost-effective electron beam-based method; and further, that it functioned well as a hole-transport layer (HTL) in perovskite solar cells (PeSCs). The rGO/PVP composites were produced by electron-beam irradiation-induced reduction of GO/PVP mixtures in ethanol/distilled water (50 v/v %), without any heat or reducing agents. The prepared rGO/PVP showed dispersion stability of six months, even in an aqueous alcoholic solvent of 5 mg/mL. Its solution-processed thin film demonstrated a uniform, smooth surface, and full-cover morphology, a good conductivity of ~0.2 S/cm, and a high work function of 5.15 eV. As a result, the solution-processed rGO/PVP as HTL for the PeSCs outweighed the conventional graphene nanoflakes (GNFs), producing higher device efficiency. Worthy of note, the rGO/PVP-based PeSCs showed better power conversion efficiency (PCE) and device stability than the reference poly (3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS)-based counterpart. This finding demonstrates that the rGO/PVP composite, which is easily producible via cost-effective and large-scale affordable electron beam technology, could provide a promising solution-processable GNFs-based HTL for long-lasting high-performance PeSCs.

As an alternative hole transport layer (HTL) to poly(3,4-ethylendioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), we investigated V2O5 thin films fabricated by simple brush painting without any post-treatments. Polymer solar cells (PSCs) with V2O5 fabricated by brush painting showed superior performance to that of conventional PEDOT:PSS based system; in particular, higher FF was obtained. Because more hydrophobic oxide surface induces better physical contact and better wetting of active blends, lower RS is obtained; thus, the resulting device shows higher performance. PSC with brush painted V2O5 at 50 °C using 0.99 vol% vanadium (V) oxytriisopropoxide in isopropyl alcohol exhibited the best power conversion efficiency (PCE) of 3.83%. Furthermore, employment of V2O5 as HTL leads to significant improvement in long-term stability in air (dropping of PCE of conventional PEDOT:PSS system to ~0% and retention of PCE of V2O5 based PSC to over 60% after exposure in air for 96 h without any encapsulation).

In this study, we synthesized Au nanoparticles (AuNPs) in polyacrylonitrile (PAN) thin films using a simple annealing process in the solid phase. The synthetic conditions were systematically controlled and optimized by varying the concentration of the Au salt solution and the annealing temperature. X-ray photoelectron spectroscopy (XPS) confirmed their chemical state, and transmission electron microscopy (TEM) verified the successful synthesis, size, and density of AuNPs. Au nanoparticles were generated from the thermal decomposition of the Au salt and stabilized during the cyclization of the PAN matrix. For actual device applications, previous synthetic techniques have required the synthesis of AuNPs in a liquid phase and an additional process to form the thin film layer, such as spin-coating, dip-coating, Langmuir-Blodgett, or high vacuum deposition. In contrast, our one-step synthesis could produce gold nanoparticles from the Au salt contained in a solid matrix with an easy heat treatment. The PAN:AuNPs composite was used as the charge trap layer of an organic nano-floating gate memory (ONFGM). The memory devices exhibited a high on/off ratio (over 106), large hysteresis windows (76.7 V), and a stable endurance performance (>3000 cycles), indicating that our stabilized PAN:AuNPs composite film is a potential charge trap medium for next generation organic nano-floating gate memory transistors.