Good Photovoltaic Performance Research Articles

Carbon Nano‐Onion and Zinc Oxide Composites as an Electron Transport Layer in Inverted Organic Solar Cells

AbstractWe report a facile chemical method to synthesize hybrid nanocomposites containing carbon nano‐onions (CNOs) and zinc oxide or hydroxide. The structure, surface morphology, optical properties and surface area of the CNOs were characterized by X‐ray diffraction, scanning electron microscopy with energy dispersive spectroscopy, transmission electron microscopy, thermogravimetric analysis, infrared and Raman spectroscopies, and adsorption/desorption N2 techniques. For the first time, we demonstrate the fabrication of bulk heterojunction organic solar cell devices utilizing hybrid nanocomposites containing CNOs and ZnO as the electron transport layer. This configuration showed good photovoltaic performance with maximum external quantum efficiencies of 16.5 and 48.9% and power conversion efficiencies of 0.42 and 1.49% for the pristine ZnO and CNO/ZnO (mCNO : mZnO=1 : 4) layers, respectively.

Real time nanoplasmonic sensing for monitoring CH3NH3PbI3 perovskite formation in mesoporous TiO2 films

The formation of methylammonium lead iodide (CH3NH3PbI3) perovskite into mesoporous titania (TiO2) scaffold via a sequential deposition method is known to offer high quality films for good photovoltaic device performance. The local kinetics at the lower interface between the mesoporous TiO2 film and the collecting electrode govern perovskite growth and formation. Here, we have used a NanoPlasmonic Sensing (NPS) approach with gold (Au) nanosensors to monitor the formation of CH3NH3PbI3 perovskite at the lower interface of up to 650 nm mesoporous TiO2 films. This technique provides time-resolved spectral shifts of the localized surface plasmon resonance at different operating temperatures and methylammonium iodide (CH3NH3I3) concentrations by recording changes in the local vicinity of the Au nanosensors at the mesoporous TiO2 film interface. Analytical studies included ellipsometry, scanning electron microscopy, X-ray diffraction, and photoluminescence spectroscopy. The results show that both the intensity of the NPS response and NPS rate constants are correlated with the operating concentrations and temperatures of CH3NH3I3 as well as CH3NH3PbI3 perovskite growth in mesoporous TiO2.

Highly Crystalline Near-Infrared Acceptor Enabling Simultaneous Efficiency and Photostability Boosting in High-Performance Ternary Organic Solar Cells.

The near-infrared (NIR) absorbing fused-ring electron acceptor, COi8DFIC, has demonstrated very good photovoltaic performance when combined with PTB7-Th as a donor in binary organic solar cells (OSCs). In this work, the NIR acceptor was added to state-of-the-art PBDBT-2F:IT4F-based solar cells as a third component, leading to (i) an efficiency increase of the ternary devices compared to the binary solar cells in the presence of the highly crystalline COi8DFIC acceptor and (ii) much-improved photostability under 1-sun illumination. The electron transport properties were investigated and revealed the origin of the enhanced device performance. Compared to the binary cells, the optimized ternary PBDBT-2F:COi8DFIC:IT4F blends exhibit improved electron transport properties in the presence of 10% COi8DFIC, which is attributed to improved COi8DFIC molecular packing. Furthermore, transient absorption spectroscopy revealed a slow recombination of charge carriers in the ternary blend. The improved electron transport properties were preserved in the ternary OSC upon aging, while in the binary devices they seriously deteriorated after simulated 1-sun illumination of 240 h. Our work demonstrates a simple approach to enhance both OSC efficiency and photostability.

Synthesis, characterization, optical properties, computational characterizations, QTAIM analysis and cyclic voltammetry of new organic dyes for dye-sensitized solar cells

Abstract In recent years, dye-sensitized solar cells (DSSCs) have regarded as potential solar cells for the next generation of photovoltaic technologies. Many organic compounds are explored and used in DSSCs to produce low-cost devices and improve the cell efficiency. In this work, three new heterocyclic purple dyes are synthesized from the reaction of 3-nitropyrazolo[1,5-a]pyridine with various arylacetonitriles for dye-sensitized solar cells (DSSCs), exhibiting high molar extinction coefficients and a broad absorption range led to the good photovoltaic performance of 6.95–7.18%. Physical spectral, analytical data and optical properties are established the structures of the new dyes. The optimized geometries and relevant frontier orbitals of the dyes are obtained by density functional theory (DFT) at the level of B3LYP/6-311 + G(d,p). Electrostatic potential maps and electron density maps of the dyes were also obtained by atoms in molecules (AIM) analysis. Cyclic voltammetry measurement was performed to evaluate the electrochemical properties of the dyes and reversible oxidation waves were observed for them.

Fluorinated fulleropyrrolidine as universal electron transport material for organic-inorganic and all-inorganic perovskite solar cells

Abstract [6,6]-Phenyl-C61-butyric acid methylester (PC61BM) has been widely used as electron transport material (ETM) for both organic-inorganic hybrid and all inorganic perovskite solar cells (PeSCs) with inverted structure. However, PC61BM still remains to be improved due to its low electrical conductivity and inferior passivation effect towards perovskite. In this work, we synthesize two perfluorophenyl-substituted fulleropyrrolidines, 2-(perfluorophenyl)-5-phenyl-C60-fulleropyrrolidine (FP-i) and 2,5-bis-(perfluorophenyl)-C60-fulleropyrrolidine (FP-ii) via a modified 1,3-dipolar cycloaddition reaction. FP-i and FP-ii are introduced into inverted PeSCs based on organic-inorganic hybrid and all inorganic perovskites (CH3NH3PbCl3-xIx and CsPbI2Br) as ETMs. The PeSCs based on FP-i and FP-ii display good photovoltaic performance and device stability, which are superior or comparable to those with PC61BM. The mechanism studies reveal that FP-i and FP-ii possess higher electrical conductivity, more significant passivation capacity and enhanced hydrophobicity but slightly lower low unoccupied molecular orbital (LUMO) levels. These results suggest that FP-i and FP-ii are universal ETMs for both organic-inorganic hybrid and all inorganic PeSCs, which are better or comparable to conventional ETM of PC61BM.

Synthesis and Photovoltaic Effect of Electron-Withdrawing Units for Low Band Gap Conjugated Polymers Bearing Bi(thienylenevinylene) Side Chains.

A novel (E)-5-(2-(5-alkylthiothiophen-2-yl)vinyl)thien-2-yl (TVT)-comprising benzo[1,2-b:4,5-b’]dithiophene (BDT) derivative (BDT-TVT) was designed and synthetized to compose two donor-acceptor (D-A) typed copolymers (PBDT-TVT-ID and PBDT-TVT-DTNT) with the electron-withdrawing unit isoindigo (ID) and naphtho[1,2-c:5,6-c′]bis[1,2,5]thiadiazole (NT), respectively. PBDT-TVT-ID and PBDT-TVT-DTNT showed good thermal stability (360 °C), an absorption spectrum from 300 nm to 760 nm and a relatively low lying energy level of Highest Occupied Molecular Orbital (EHOMO) (−5.36 to –5.45 eV), which could obtain a large open-circuit voltage (Voc) from photovoltaic devices with PBDT-TVT-ID or PBDT-TVT-DTNT. The photovoltaic devices with ITO/PFN/polymers: PC71BM/MoO3/Ag structure were assembled and exhibited a good photovoltaic performance with a power conversion efficiency (PCE) of 4.09% (PBDT-TVT-ID) and 5.44% (PBDT-TVT-DTNT), respectively. The best PCE of a PBDT-TVT-DTNT/PC71BM-based device mainly originated from its wider absorption, higher hole mobility and favorable photoactive layer morphology.

Scalable and Green Fabrication of Thin-Film Solar Cells Using Solution Processed Inkjet Printing Method

Inkjet printing has recently emerged as a scalable and green processing method to develop thin film electronics.[1-8] Here, we report a low-cost and efficient inkjet printing method for the development of a solar cell device. The commonly used electron collection layers require high post- sintering temperatures (~ 500° C) which are unfavorable for plastic and textile-based substrates. The electron transport layer was constructed by reduced graphene oxide – TiO2 nanocomposite ink which was uniformly printed over the plastic and FTO substrates. The graphene in the nanocomposite provides excellent charge-collection due to its high conductivity and enables device fabrication at low processing temperatures. The other components of the solar cell were also deposited over the electron transport layer. The developed solar cell with reduced graphene oxide – TiO2 electron transport layer shows good photovoltaic performance with a power conversion efficiency of ~ 21 % which was 30 % higher than the TiO2 based electron transport layer. The comparative impedance spectra also confirm that the improvement in the photovoltaic performance was due to the better charge collection generated by the reduced graphene oxide layers. The device also shows excellent stability with 94 % retention of the initial power conversion efficiency after storing it in an ambient condition with a relative humidity of ~ 40 % for 120 h. The device with plastic substrate also displays good flexibility with negligible change in the device performance in the flexed conditions. The desirable output for solar cell devices can be easily achieved by changing the ink concentrations, number of printing layers, and by replacing the size and shape of the digital drawings. So, the inkjet printing technology has a huge potential for the development of thin, low-cost, scalable, and flexible solar cell devices.

Towards high efficiency inverted Sb2Se3 thin film solar cells

Sb2Se3 as a rising star semiconducting material with a bandgap of 1.1 eV has played a role of the absorber in the thin film solar cells. Regular device architectures such as metal grids/buffer/Sb2Se3/metal electrode, or transparent electrode film/buffer/Sb2Se3/metal electrode have been fabricated both experimentally and theoretically and exhibit relatively good photovoltaic performances. Yet the theoretical power-conversion efficiency is not competitive with commercial thin film solar cells. Therefore, we propose an inverted architecture with top illumination through ITO substrate, with allocating the hole transport layer (HTL) on top of Sb2Se3 and stacking electron transport layer beneath the Sb2Se3. Indeed an optimal power conversion efficiency of 24.7% and fill factor of 80.3% have been simulated in the solar devices with the selected NiO as the HTL. The improvement in solar cell performances stems from the satisfying bandgap alignment and improved hole conductivity due to the high acceptor concentration of the chosen material. Further increase of the device performances depend on the high quality Sb2Se3 thin films, i.e., with negligible defects states and the suppression of defects at the Sb2Se3/HTL interfaces.

Molecular packing control enables excellent performance and mechanical property of blade-cast all-polymer solar cells

All-polymer solar cells (all-PSCs) are the most promising power generators for flexible and portable devices due to excellent morphology stability and outstanding mechanical property. Previous work indicates high crystallinity is beneficial to device performance but detrimental to mechanical property, therefore identifying the optimized ratio between crystalline and amorphous domains becomes important. In this work, we demonstrated highly efficient and mechanically robust all-PSCs by blade-coating technology in ambient environment based on PTzBI:N2200 system. By controlling the aggregation in solution state and ultrafast film formation process, a weakly ordered molecular packing morphology as well as small phase separation is obtained, which leads to not only the good photovoltaic performance (8.36%-one of the best blade-cast device in air) but also prominent mechanical characteristic. The controlled film shows a remarkable elongation with the crack onset strain of 15.6%, which is the highest result in organic solar cells without adding elastomers. These observations indicate the great promise of the developed all-PSCs for practical applications toward large-area processing technology.

Polyaniline (PANI)/reduced graphene oxide (rGO) composite as a counter electrode for dye solar cells.

Polyaniline (PANI)-reduced graphene oxide (rGO) based transparent counter electrodes have been fabricated for dye sensitized solar cells as an alternative to the expensive platinum (Pt) counter electrodes. Here, the graphene oxide (GO) added during the polymerization of PANI will subsequently reduce to rGO. The concentration of graphene oxide (GO) was varied in PANI matrix to optimize the performance of dye solar cell (DSC). With 1% GO addition in PANI, 9.68% current density was increased, consequently, 13.9% photocurrent density was found to be increased as compared to pure PANI. Electrochemical impedance spectroscopy (EIS) disclosed that the incorporation of 1% GO in PANI caused the double-layer capacitance to increase by 10 times compared to pure PANI. This implies that graphene is capable of enhancing the specific surface area and catalytic capacity of PANI. Optical transparency of PANI-1% GO counter electrode was found to be ∼67% between the wavelengths of 500 to 600 nm. Such transparency enables the construction of bifacial DSCs. Although the photo conversion efficiency (PCE) of DSC with PANI-1% GO counter electrode is still not comparable to the one with Pt counter electrode but it is sufficient to be considered as the replacement as it exhibits good photovoltaic performance and optical characteristics together with an exceptionally low cost material.

Wide bandgap donor-acceptor conjugated polymers with alkylthiophene as side chains for high-performance non-fullerene polymer solar cells

Abstract Four wide bandgap donor-acceptor (D-A) conjugated polymers, i.e. P-diF2T, P-TT, P-BDT and P-NDT, with bis(5-(2-decyltetradecyl)-[2,3′-bithiophen]-2′-yl)arylenes as D-units and 2-propyl-5,6-difluorobenzo[d][1,2,3]triazole (ffTAZ) as A unit were synthesized for photovoltaic applications. In P-diF2T, P-TT, P-BDT and P-NDT, 3,3′-difluoro-2,2′-bithiophene (diF2T), thieno[3,2-b]thiophene (TT), benzo[1,2-b:4,5-b']dithiophene (BDT) and naphtho[1,2-b:5,6-b']dithiophene (NDT) were used as aryl central units, respectively, to adjust the properties of the polymers. The optical bandgap is 1.83 eV for P-diF2T, 1.85 eV for P-TT, 1.90 eV for P-BDT and 2.04 eV for P-NDT. All four polymers show temperature-dependent aggregation behavior in solution, and their absorption spectra are complementary with that of non-fullerene acceptor (NFA) 3,9-bis(2-methylene-(3-(1,1-dicyanomethylene)-indanone))-5,5,11,11-tetrakis(5-hexylthiophen-2-yl)-dithieno[2,3-d:2′,3′-d′]-s-indaceno[1,2-b:5,6-b′]dithiophene (ITIC-Th). Polymer solar cells (PSCs) based on these polymers and ITIC-Th were fabricated and characterized. Power conversion efficiencies (PCEs) higher than 7% were demonstrated for all polymers. The devices based on P-diF2T exhibited the highest PCE up to 10.08% with a high fill factor (FF) of 0.741. The good photovoltaic performance of P-diF2T is attributed to the synergies of the low-lying highest occupied molecular orbital (HOMO) energy level of the polymer and the favorable microstructures and morphology and thereby high and balanced charge carrier mobilities of the blend films. This study suggested that adjusting aromatic D units together with using alkylthiophene as side chains is an effective approach to design donor polymers for high performance PSCs based on NFA.

Photovoltaic Performance Enhancement of Silicon Solar Cells Based on Combined Ratios of Three Species of Europium-Doped Phosphors.

This paper presents a scheme for the enhancement of silicon solar cells in terms of luminescent emission band and photovoltaic performance. The proposed devices are coated with an luminescent down-shifting (LDS) layer comprising three species of europium (Eu)-doped phosphors mixed within a silicate film (SiO2) using a spin-on film deposition. The three species of phosphor were mixed at ratios of 0.5:1:1.5, 1:1:1, or 1.5:1:0.5 in weight percentage (wt %). The total quantity of Eu-doped phosphors in the silicate solution was fixed at 3 wt %. The emission wavelengths of the Eu-doped phosphors were as follows: 518 nm (specie-A), 551 nm (specie-B), and 609 nm (specie-C). We examined the extended luminescent emission bands via photoluminescence measurements at room temperature. Closely matching the luminescent emission band to the high responsivity band of the silicon semiconductor resulted in good photovoltaic performance. Impressive improvements in efficiency were observed in all three samples: 0.5:1:1.5 (20.43%), 1:1:1 (19.67%), 1.5:1:0.5 (16.81%), compared to the control with a layer of pure SiO2 (13.80%).

ZnO nanowire based CIGS solar cell and its efficiency enhancement by the piezo-phototronic effect

Cu(In,Ga)Se2(CIGS)-based heterostructures have been thought to be one of the most prospective thin film solar cells. However, considering cost competitiveness, researchers are still seeking for new methods to improve the power conversion efficiency (PCE). In this work, the ZnO nanowires are first introduced into the CIGS-based solar cells to substitute the ZnO film for well developing the piezoelectric effect. Interestingly, the solar cells exhibit very good photovoltaic performances with PCE of 9.83% for rigid device and 5.43% for flexible device, the PCE of which is even larger than that of the corresponding ZnO film CIGS devices. Moreover, by exerting piezo-phototronic effect of the ZnO nanowires, the PCE of the rigid device is modulated from 9.83% to 11.40% with vertical pressure increasing from 0 to 2 MPa, and the PCE of the flexible device improves from 4.82% to 5.96% with external strain changing from a 0.74% tensile strain to a −0.74% compressive strain. This study demonstrates that introducing ZnO nanowires as well as the associated piezo-phototronic effect provides an ideal approach for improving the performances of CIGS-based solar cells.

DFT+U study on the electronic structures and optical properties of pyrite and marcasite

Pyrite is an attractive material as its good photovoltaic performance; however, the presence of marcasite phase is considered to be detrimental to pyrite as a photovoltaic material due to its low band gap. Density functional theory (DFT) combined with Hubbard U correction was used to perform the calculations on the crystal structures, electronic structures, and optical properties of pyrite and marcasite in the present work. When a U value of 1.5 eV is adopted to Fe 3d, the band gaps of pyrite and marcasite are calculated to be 1.05 eV and 1.33 eV, respectively, compared to 0.54 eV and 1.05 eV without adopting U. It is found that the fundamental band gap in pyrite is formed by Fe 3d-S 3p transition while in marcasite it is formed by Fe 3d-Fe 3d transition. The larger band gap of marcasite suggests that the presence of marcasite could not deteriorate the photovoltaic performance of pyrite. The subsequent calculations on the optical properties confirmed a very similar optical absorption performance of marcasite to pyrite, even finding a redshift of the optical absorption edge of marcasite compared to pyrite in the low energy region and a wider absorption range in the high energy region. These results were associated with the Fe octahedron differences in the crystals, which resulted in a different d orbital splitting scheme proposed in our study.

Lattice dynamics, phase transition, and tunable fundamental band gap of photovoltaic (K,Ba)(Ni,Nb) O3−δ ceramics from spectral measurements and first-principles calculations

Ferroelectrics have long been recognized as one of the candidate class of materials for applications in photovoltaic devices. Recently, ferroelectric perovskite $(\text{K},\text{Ba})(\text{Ni},\text{Nb}){\mathrm{O}}_{3\ensuremath{-}\ensuremath{\delta}}$ has been successfully synthesized and demonstrated to have a near-optimal band gap (1.39 eV), exhibiting good photovoltaic performance. However, the connection between the structural order-disorder transformation, electronic structure, bulk photovoltaic, and photocatalytic properties remains not well understood. Here, we investigate the phase transition evolutions of lead-free ${[{\mathrm{KNbO}}_{3}]}_{1\ensuremath{-}x}{[{\mathrm{BaNi}}_{1/2}{\mathrm{Nb}}_{1/2}{\mathrm{O}}_{3\ensuremath{-}\ensuremath{\delta}}]}_{x}$ ($\mathrm{KBNNO}x$, $x=0--0.5$) ceramics via x-ray diffraction (XRD), Raman scattering, and computational evidences. The lattice dynamics and the origin of the successive rhombohedral$\ensuremath{\rightarrow}$orthorhombic$\ensuremath{\rightarrow}$tetragonal$\ensuremath{\rightarrow}$cubic phase transitions have been systemically explored based on temperature-dependent XRD peak positions and phonon modes under different geometries. Moreover, the differences in the phase transition temperature and interior structure between the solid solution $x=0.2$ and the end member $x=0$ highlight local and nonlocal characteristics, which are helpful for understanding the photovoltaic mechanisms. Additionally, the robust photocatalytic decoloration effect on methylene blue can further confirm the photon-generated carrier behavior in the partly structural disordered orthorhombic phase. This identification of structural phases, combined with the ability to perform photocatalytic decoloration, give some insights on promising oxide applications as semiconducting ferroelectric absorbers and carrier-separating layers in photocatalytic or photovoltaic devices.

Highly efficient organic indolocarbazole dye in different acceptor units for optoelectronic applications—a first principle study

A series of novel organic dyes (ICZA1, ICZA2, ICZA3, ICZA4) with D-π-A structural configuration incorporating indolo[3,2,1-jk]carbazole moiety as donor (D) unit, thiophene as π-linker and 2-cyanoacrylic acid as acceptor unit were investigated using density functional theory (DFT) and time-dependent DFT (TD-DFT) methods. Indolo[3,2,1-jk]carbazole-based D-π-A dyes composed of different acceptor groups were designed. By modulating acceptor unit, the efficiency of D-π-A dye-based dye-sensitized solar cells (DSSCs) can be further improved. In the present work, four novel push-pull organic dyes only differing in electron acceptor, have been designed based on the experimental literature value of IC-2. In order to further improve the light harvesting capability of indolo[3,2,1-jk]carbazole dyes, the acceptor influence on the dye performance were examined. The NLO property of the designed dye molecules can be derived as polarizability and hyperpolarizability. The calculated value of ICZA2 dye is the best candidate for NLO properties. Furthermore, the designed organic dyes exhibit good photovoltaic performance of charge transfer characteristics, driving force of electron injection, dye regeneration, global reactivity, and light harvesting efficiency (LHE). From the calculated value of ICZA4 dye, it has been identified as a good candidate for DSSCs applications. Finally, it is concluded that the both ICZA2 and ICZA4 dyes theoretically agrees well with the experimental value of IC-2 dye. Hence, the dyes ICZA2 and ICZA4 can serve as an excellent electron withdrawing groups for NLO and DSSCs applications.

The influence of perovskite precursor composition on the morphology and photovoltaic performance of mixed halide MAPbI3-xClx solar cells

A set of various perovskite precursor formulations was investigated to elucidate correlations between precursor composition and the crystal structure, film morphology as well as photovoltaic activity of H3CNH3PbI3-xClx perovskite solar cells. Three precursor solutions in dimethylfromamide (DMF) with defined ratios of lead(II) halide (PbI2 and/or PbCl2) and methylammonium halide (H3CNH3I (MAI) and H3CNH3Cl (MACl)) such as 1:3 (PbCl2:MAI), 1:1:4 (PbI2:PbCl2:MAI) and 1:1:1 (PbI2:MAI:MACl) were used to prepare solar cells in primarily ambient atmosphere. Processing the 1:3 (PbCl2:MAI) solution in ambient atmosphere yielded perovskite films with rather non-uniform morphology and devices with moderate performance. Perovskite thin films prepared from the 1:1:4 (PbI2:PbCl2:MAI) and 1:1:1 (PbI2:MAI:MACl) formulation showed nearly identical features, high crystallinity, large and compact micrometer-sized crystal domains, and good photovoltaic performance. This indicates that the overall ionic composition in the precursor solution is crucial for the perovskite formation, the source of these ions, however, appears nonrelevant. Furthermore, the effect of different electron transport layers (ETL), PCBM, bis-PCBM, and N-[4-(benzothiadiazol-4-yl)phenyl]-N′-(1-nonyldecyl)perylene-3,4,9,10-tetracarboxdimide (a-PTCDI) on the photovoltaic performance was analyzed. The highest hysteresis-free power conversion efficiency (PCE) was achieved with PCBM (12.8%) followed by a-PTCDI (8.4%) and bis-PCBM (6%). The degradation of MAPbI3-xClx based devices stored in nitrogen atmosphere was primarily revealed by a loss in fill factor.

Low-cost synthesis of heterocyclic spiro-type hole transporting materials for perovskite solar cell applications

The new spirobased PSC used HTM SFX-TPAM with good photovoltaic performance was prepared through low cost facile route.

Synthesis and Characterization of an Efficient Hole-Conductor Free Halide Perovskite CH3NH3PbI3 Semiconductor Absorber Based Photovoltaic Device for IOT

Organometal halide perovskite (CH3NH3PbI3) absorber was synthesized from CH3NH3I and PbI2 in N, N dimethylformamide by solution spin coating process. Characterization by X-ray diffraction, optical and electron microscopy studies confirmed a well-formed nano-crystalline tetragonal pervoskite structure. The synthesized CH3NH3PbI3 was used as a photo absorber material in a hole-conductor free photovoltaic device with TiO2 as an electron conductor. This configuration of the perovskite photovoltaic device exploits the role of CH3NH3PbI3 simultaneously as light absorber and hole-conducting material. We report two device configurations: (a) with a compact TiO2 buffer layer introduced between the porous TiO2 and FTO and (b) without the compact TiO2 layer over the FTO substrate. The simple solar cell structure FTO/TiO2/CH3NH3PbI3/Agpresented here shows good photovoltaic performance under illumination with standard AM1.5 sunlight. For the champion devices from the two structures, (a) and (b), we obtained short circuit photocurrent densities asJsc = 17.4 mA/cm2 and 19.5 mA/cm2, open circuit voltage Voc = 1.0 V and 1.45 V, fill factor FF = 0.54 and 0.29 and a power conversion efficiency (PCE) of 9.39% and 8.19% respectively under solar light intensity flux of 100 mW/cm2. We find that structure (a) offers significantly better device parameters. The results of the present work suggest a route to realize a simple, low cost and highly efficient perovskite photovoltaic device. These devices could be realized in miniaturized sensors and electronic components applied in Internet of Things (IoT).

A novel small molecule based on naphtho[1,2-b:5,6-b′]dithiophene benefits both fullerene and non-fullerene solar cells

The all-round small molecule donor NDTR exhibited good photovoltaic performance in both fullerene and non-fullerene systems.