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Organic–inorganic halide perovskites possess excellent chemical, optical, and electronic properties that make them attractive for next-generation solar cells. An important target for the further improvement of perovskite-based solar cells is to eliminate or reduce the use of the heavy metal lead. Herein, we systematically investigated the performance of FAPb1−xSnxI3 mixed metal halide perovskites. The addition of Sn led to the stabilization of the perovskite phase and the low temperature of 100 °C was enough to result in the formation of the perovskite phase. The efficiency of the solar cell fabricated in this study is over 10% at x = 0.5, owing to the improved light harvesting in spite of the reduced open voltage. As more Sn was added, the device performance gradually deteriorated. Importantly, we performed stability tests under white light illumination and demonstrated that the FASn0.5Pb0.5I3 material might be intrinsically stable in a nitrogen environment. These results show that the device based on the FASn0.5Pb0.5I3 absorber without encapsulation retained over 85% of the initial efficiency for 100 h in nitrogen, indicating that a highly efficient perovskite solar cell with reduced Pb content and long-term stability could be realized.

Methylammoniumn lead iodide perovskites have attracted great attention in photovoltaic research community. In this work, we demonstrate the results of studies focusing on the chemical reaction of CH3NH3PbI3-xClx layer formation during the annealing of perovskite precursor films. We identified two kinds of grain morphologies during the formation of perovskite films grown from non-stoichiometric precursor solution. To form single-phase and high absorbance perovskite films, higher concentration of chloride in precursor solution needs longer annealing time and only a very low Cl content could be incorporated in the final CH3NH3PbI3-xClx films. Adding PbCl2–3CH3NH3I to PbI2–CH3NH3I precursor solution can allow a good control of the growth rate and morphology for the final perovskite film, and is beneficial to the photovoltaic performance of perovskite devices. By employing the precursor solutions of PbCl2, PbI2 and CH3NH3I with a mole ratio of 1:1:4 and inserting an ultrathin amino-functionalized polymer interlayer, we achieved planar perovskite solar cell with maximum power conversion efficiency of over 15%.

Cubic boron nitride (cBN) composites, using Al and HfC as the additives, were sintered under static high pressure of 5.0 GPa and at temperatures of 700 °C–1500 °C for 80 s. By analyzing the phase components of the sintered samples through the X-ray diffraction (XRD) analysis, we found that when the temperature increased from 700 °C to 900 °C, cBN reacted with Al and HfC, and produced AlN, AlB 2 , HfB 2 and B 2 C 5 N 2 . Above 1000 °C, AlB 2 was not stable. It decomposed and finally generated AlB 12 . At the meantime, the content of AlN, AlB 12 , HfB 2 and B 2 C 5 N 2 increased with Al disappearing. The Vickers hardness of the sintered samples increased with increasing the cBN content. The SEM and the abrasion ratio tests revealed that the well-sintered samples with homogeneous microstructure and the best wear resistance could be obtained at 5.0 GPa, 1300 °C for 80 s with the cBN content of 80 wt.%.

Organic–inorganic halide perovskites possess excellent chemical, optical, and electronic properties that make them attractive for next-generation solar cells. In this paper, we introduce all-low-temperature processed perovskite solar cells using metal sulfide as an electron transport layer. First, we evaluated the alignment of energy levels at the perovskite/metal sulfide layer interface. The properties of metal sulfide and the perovskite layer, as well as the corresponding device performance, were then investigated. Using a CdS layer as an electron transport layer, we have achieved a maximum power conversion efficiency of 11.2% under reverse scans. The successful use of the CdS layer in perovskite solar cells likely would create new pathways and opportunities for the advancement of device design.

Flexible Cu2ZnSnS4 (CZTS) solar cell absorbers were prepared by sulfurizing Cu–Zn–Sn precursors which were co-electrodeposited on Mo-coated molybdenum foil in a one-step process. A photovoltaic device with 3.82% conversion efficiency based on the illumination area of 0.35 cm2 was attained, which is the first efficiency report of flexible CZTS-based solar cells on molybdenum foil.

This work is the first report of using a deep eutectic solvent named Reline as a green electrolyte to electrodeposit CZTS films for photovoltaic applications. This is successfully achieved by co-electrodepositing Cu–Zn–Sn precursor thin films in Reline and sulfurizing the Cu–Zn–Sn precursors in a mixture of H2S and N2 at 550 °C for 1 h. The CZTS films are uniform and compact on a microscopic scale, which translates to a benign photoresponse of the CZTS solar cell. Photovoltaic devices were prepared from the films and an efficiency of 3.87% has been achieved. The device performance indicates that Reline is a viable green solvent for the electrodeposition of CZTS thin film solar cells in a low cost way.

In this paper, CdTe solar cells of ~10% efficiency with a structure of anti-radiation glass/ITO/ZnO/CdS/CdTe/ ZnTe/ZnTe:Cu/Au were irradiated by 1.7 MeV irradiation with various fluences. Testing methods, such as light and dark IV, quantum efficiency, admittance spectroscopy were used to study the performances of CdTe cells before and after irradiation. Comprehensive electron irradiation damage effect on the characteristics and physical mechanism of charge transport were analyzed. The results show that the main junction CdS/CdTe is easy being destroyed and there are two defects induced by high energy electron irradiation, whose positions in the forbidden band are close to 0.46±0.05 eV and 0.44±0.04 eV above the valence band, and capture cross sections are 1.32×10-15 cm2 and 3.09×10-15 cm2, respectively, and under different irradiation fluences, the quantum efficiency of the solar cells decreases, especially in 550nm-800nm. As a result, the short circuit current decreases after irradiation.