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Shading on photovoltaic (PV) modules due to shadows, covering, dust, etc., usually characterized as semi-transparent, will significantly affect the power generation capacity. No systematic study has considered the impact of semi-transparent coverings on the power generation capacity of PV modules. This paper covers a single cell in the PV module using a covering with a transmittance of 18.55% and systematically investigates its impact on the power generation capacity. The open-circuit voltage (Voc) of the PV module is nearly unaffected by semi-transparent coverings because the covered cell can be considered as working at a lower irradiance and thus can output a voltage close to that of the uncovered cell. The short-circuit current (Isc) is significantly affected by coverings because it is co-contributed by the photocurrent (evaluated based on the covering ratio R and transmittance) and the reverse bias current ΔIsc (the covered cell is in a reverse bias state). The ΔIsc increases with R because more charge accumulates at the bi-ends of the covered cell; but, it decreases at full covering, which implies that in a partially covered case the uncovered part contributes more to ΔIsc than the covered part. The fill factor (FF) of the PV module first increases and then decreases with R, as the equivalent resistance of the covered cell increases rapidly with R, which replaces the wire resistance in dominating the series resistance of the PV module when R > 0.6. This work is of great theoretical significance in analyzing the output characteristics of PV modules under real conditions. [ABSTRACT FROM AUTHOR]

Highlights: A graded inverted solar cell configuration is developed by hole-transport management aiming to suppress interface defects-induced non-radiative recombination for efficient hole transport. NiOx-based inverted PSCs present a power-conversion-efficiency over 23% with a high fill factor of 0.84 and open-circuit voltage of 1.162 volts, one of the best performances reported so far for 1.56-electron volt bandgap formamidinium-based triple-halide perovskites. Devices show high operational stability over 1,200 h during T90 lifetime measurement under 1-sun illumination in ambient-air conditions. NiOx-based inverted perovskite solar cells (PSCs) have presented great potential toward low-cost, highly efficient and stable next-generation photovoltaics. However, the presence of energy-level mismatch and contact-interface defects between hole-selective contacts (HSCs) and perovskite-active layer (PAL) still limits device efficiency improvement. Here, we report a graded configuration based on both interface-cascaded structures and p-type molecule-doped composites with two-/three-dimensional formamidinium-based triple-halide perovskites. We find that the interface defects-induced non-radiative recombination presented at HSCs/PAL interfaces is remarkably suppressed because of efficient hole extraction and transport. Moreover, a strong chemical interaction, halogen bonding and coordination bonding are found in the molecule-doped perovskite composites, which significantly suppress the formation of halide vacancy and parasitic metallic lead. As a result, NiOx-based inverted PSCs present a power-conversion-efficiency over 23% with a high fill factor of 0.84 and open-circuit voltage of 1.162 V, which are comparable to the best reported around 1.56-electron volt bandgap perovskites. Furthermore, devices with encapsulation present high operational stability over 1,200 h during T90 lifetime measurement (the time as a function of PCE decreases to 90% of its initial value) under 1-sun illumination in ambient-air conditions. [ABSTRACT FROM AUTHOR]

The passivation of perovskite bulk and heterointerface defects is one of the most significant ways to enhance the efficiency and operational stability of perovskite solar cells (PSCs). So far, ammonium‐based alkylamine halides have been considered as effective passivation materials to reduce defects of the perovskite absorber layer. Herein, roles of long‐chain alkylamine ligands (LALs) in triple‐halide perovskites are systematically studied for achieving efficient NiOx‐based inverted PSCs. Two kinds of LALs oleylammonium (OAm) and phenethylammonium (PEA), as perovskite bulk and interface passivation agents, respectively, are introduced. It is found that both OAm and PEA ligands cannot only assist their crystal growth with vertical orientation, but also suppress triple‐halide perovskite bulk and interface defects. As precursor additives, OAm ligands can be used as organic spacers to assist the generation of the 2D@3D perovskite bulk crystals. 2D@3D/2D perovskite heterostructures are further formed when the 2D@3D perovskite bulk film is post‐treated by PEA ligands. As a result, such strategies enable hysteresis‐free and highly efficient NiOx‐based triple‐halide inverted PSCs. [ABSTRACT FROM AUTHOR]

[Display omitted] Designing heterojunction catalysts with energy effects at the interface, particularly combining the surface structure advantages of super-hydrophilic interfaces with the high activity advantages of bimetal synergistic optimisation, is the key to developing economical and efficient industrial electrocatalytic water-splitting catalysts. In this study, a coupled nanoflower-like NiFe(OH) x /(Ni, Fe)Se heterostructure catalyst supported on Ni foam (NF) (NFSe@NFOH/NF) was designed and successfully prepared using hydrothermal and electrodeposition strategies. Owing to the electron interaction at the heterogeneous amorphous (NFOH)/crystalline (NFSe) interface and the bimetallic synergistic effect of Ni and Fe, the prepared NFSe@NFOH/NF exhibited excellent and stable oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) catalytic properties, with low overpotentials of 214/276 mV at 100 mA⋅cm−2 and 262/340 mV at 500 mA⋅cm−2. The assembled water electrolyser comprising NFSe@NFOH/NF || NFSe@NFOH/NF needed only small voltages of 1.73 and 1.85 V to yield current densities of 100 and 500 mA⋅cm−2, respectively. This study offers an innovative design idea for the rational adoption of interface engineering and amorphous–crystalline engineering techniques to construct catalysts with excellent catalytic activity and stability for electrocatalytic overall water splitting (EOWS) at a high current density, which further facilitates the advancement of sustainable energy technology in the future. [ABSTRACT FROM AUTHOR]

A green and efficient polymer-assisted antisolvent-mediator is developed to perfectly passivate the defects presented in polycrystalline perovskite films. Thus, the NiO x -based inverted champion cell generates a PCE of 22.21 %; meanwhile, a V oc approaching 1.20 eV is achieved for 1-square-centimeter cells. As-fabricated perovskite solar modules with 6 subcells connected in series can obtain a high V oc of 7.044 V. [Display omitted] • A green antisolvent-mediator is developed to stabilize perovskites on the NiO x hole-conductor. • The perovskite film bulk and interface defects are remarkably passivated. • Sputtering NiO x based inverted PSCs show a PCE of 22.21% and excellent stability. • The V oc approaching 1.20 V and 7.10 V for 1-square-centimeter cells and modules are achieved. Passivation of polycrystalline perovskite defects related to its surface, grain boundaries and buried interface is important to enhance the performance of perovskite photovoltaics. Here, a green and simple antisolvent-mediator contained ethylacetate and polymer polymethyl methacrylate, for the first time, is developed to stabilize the perovskite active layer. Such polymer-assisted mediators not only can facilitate perovskite crystal growth, but also passivate its interface and bulk defects. Under AM 1.5G illumination, the antisolvent-mediator processed NiO x -based inverted perovskite solar cells (PSCs) show a power conversion efficiency (PCE) of 22.21 % and a high open-circuit voltage (V oc) of 1.161 V. Besides, the devices further present a high PCE over 24 % under 0.6 suns, indicating efficient passivation of defects-induced non-radiative recombination. Importantly, a V oc approaching 1.20 V is obtained from 1-square-centimeter cells, which is the highest V oc in NiO x based inverted PSCs to the best of our knowledge. Compared to pristine cells, the antisolvent-mediators passivated cells without encapsulation retain 95 % of their initial values after 200 days. Furthermore, we can obtain a high V oc of 7.044 V for modules with 6 subcells connected in series. [ABSTRACT FROM AUTHOR]

Highlights: [•] The PCE of PSCs based on PBDTTT-C was increased to 5.35%, with 80% improvement by adding DIO. [•] The effect of DIO was investigated from the device physics researches. [•] The improvement of PCE is attributed to the improved hole transport and optical field strength in the active layer. [Copyright &y& Elsevier]

Abstract: A series of solution-processed small molecular solar cells (SMSCs) were fabricated with 2,4-bis[4-(N,N-diisobutylamino)-2,6-dihydroxyphenyl] (DIB-SQ) and [6,6]-phenyl-C-71-butyric acid methyl ester (PC71BM) as the active layer. The cells with MoO3 as anode interfacial layer and LiF as cathode interfacial layer have the maximum power conversion efficiency (PCE) 2.68%, with short circuit density (J sc ) of 8.2mA/cm2, open circuit voltage (V oc ) of 0.9V and fill factor (FF) of 36.3% under 100mW/cm2 illumination intensity. The key parameters, including J sc V oc , and FF of cells with MoO3 as anode interfacial layer and LiF as cathode interfacial layer, are improved about 54.7%, 26.9%, and 23.5% compared with these of cells using PEDOT:PSS as anode interfacial layer and LiF as cathode interfacial layer. The underlying reasons are mainly attributed to the effect of MoO3 layer on charge carrier collection and morphology of active layer. The effect of illumination intensity on the performance of cells was also discussed in detailed. [Copyright &y& Elsevier]

Abstract: The performance of polymer solar cells (PSCs), based on poly(3-hexylthiophene) (P3HT) and [6,6]phenyl-C71-butyric acid methyl ester (PC71BM), were improved by adding poly[(4,8-bis-(2-ethylhexyloxy)-benzo[1,2-b:4,5-b′](dithiophene)-2,6-diyl-alt-(4-(2-ethylhexanoyl)-thieno[3,4-b]thiophene)-2,6-diyl] (PBDTTT-C). The absorption region of the ternary blend films is extended into near infrared region (NIR). Power conversion efficiency (PCE) of the ternary blend PSCs is improved to 2.48% with 6% PBDTTT-C, which is 27% higher than the binary blend PSCs. The dominant mechanism for the PCE improvement could be attributed to the well balance between photon harvest and charge carrier transport by doping proper concentration PBDTTT-C. The energy transfer or charge carrier transfer directly between P3HT and PBDTTT-C was investigated, which are found to be positive for the performance improvement of ternary blend PSCs. [Copyright &y& Elsevier]

Abstract: Inverted polymer solar cells (IPSCs) were fabricated with cesium carbonate (Cs2CO3) modified indium tin oxide (ITO) substrates as the electrode and molybdenum trioxide (MoO3) modified Al as the anode. The Cs2CO3 dissolved in 2-ethoxyethanol was spin-coated on ITO substrates, showing snowflake-like morphology characterized by the scanning electron microscope (SEM). The absorption, X-ray diffraction as well as the morphology of the active layer were measured before and after annealing treatment. The IPSCs with annealing treatments on the active layers and MoO3 layers exhibited the maximum power conversion efficiency (PCE) approaching to 2%, with open circuit voltage (V oc ) of 0.57V, short circuit current density (J sc ) of 8.8mA/cm2 and fill factor (FF) of 38.7%. The performance of IPSCs was dramatically decreased by annealing treatment after the deposition of Al cathode, which may be due to the diffusion of Al atom crossing the MoO3 layer forming new channels for charge carrier collection. However, the new channels are not beneficial to the charge carrier collection, which is demonstrated from that the J sc of IPSCs was evidently decreased from 8.8 to 4.6mA/cm2 by annealing treatment after deposition Al layer. The annealing treatment after deposition of MoO3 could improve the interfacial contact to aid in electron extraction. [Copyright &y& Elsevier]

Abstract: Two series of P3HT-based polymer solar cell (PSCs) only with different electron acceptors PC70BM or PC60BM were investigated under the same conditions. The PSCs with PC70BM as the electron acceptor exhibit a relatively strong and broad absorption in the visible range and high external quantum efficiency, which results in a relatively high open circuit voltage (V oc ) of 0.62V, short circuit current density (J sc ) of 11.85mA/cm2 and power conversion efficiency (PCE) of 3.52%. The PSCs with PC60BM as the electron acceptor have a relatively low V oc of 0.58V, J sc of 10.68mA/cm2 and PCE of 3.02% due to the weak absorption of PC60BM in the visible light range. The function of PC70BM instead of PC60BM as electron acceptor could be summarized as follows: i) the strong absorption PC70BM in the visible range results in much more photon harvesting; ii) the relatively low electron mobility and relatively big size of PC70BM molecule influences the charge transporting and phase separation. The ultimate performances of PSCs are codetermined by the photon harvesting, exciton dissociation, charge carrier transport and collection. [Copyright &y& Elsevier]