• Energy Research

Perovskite CsPbBr3 quantum dot (CsPbBr3-QD) recovery was performed using lead scrap from lead storage batteries. The perovskite CsPbBr3-QD characteristics were analyzed using different PbO/recycled PbO2 ratios. Scanning electron microscopy (SEM) was used to observe the film surface morphology and cross-section. High-resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD) were used to observe the perovskite CsPbBr3-QDs’ structural characteristics. A photoluminescence (PL) measurement system was used to analyze the optical properties. The results show that lead scrap from lead–acid batteries as a material for perovskite CsPbBr3-QD production can be successfully synthesized. This saves material and also proves that recycling is valuable. The proposed approach is helpful for future material shortages and materials not easily accessible. Although the efficiency is not very high, this process will be purified using recycled lead in the future to achieve higher quantum yield.

Photoelectrode made of nanocable structure of ZnO nanorods (NR) coated with TiO(2) nanosheets (NSs) was investigated for CdS/CdSe quantum dot co-sensitized solar cells. ZnO NRs prepared solution reaction at 60 °C served as the backbone for direct electron transport in view of the single crystallinity of the ZnO NRs and the high electron mobility of ZnO semiconductor. Anatase TiO(2) NSs with the thickness of ∼10 nm and the length of ∼100 nm were assembled onto the surface of ZnO NRs via a solvothermal method. It was found that the thin shell of TiO(2) might have remarkable influence on the quantum dot sensitized solar cells (QDSCs) through (a) increasing the surface area of ZnO NRs to allow for adsorbing more quantum dots (QDs), which led to high short current density, (b) forming an energy barrier that hindered the electrons in the ZnO from being back to the electrolyte and QDs, and thus, reduced the charge recombination rate, resulting in prolonged electron lifetime and enhanced open voltage. In comparison with the case of ZnO NRs, the short-circuit current density, open-circuit voltage, fill factor and charge recombination resistance of ZnO/TiO(2) nanocable photoelectrode increase by 3%, 44%, 48% and 220%, respectively. As a result, a power conversion efficiency of 2.7% of QDSCs with core-shell structural nanocable photoelectrode has been obtained, which is as much as 230% of that of 1.2% obtained for ZnO NR photoelectrode.

The mismatched energy-level alignment and interface defects of the SnO2 nanoparticles' electron transport layer (ETL) and perovskite layer worsen the efficiency of the perovskite solar cell. Herein, we devise a multiple-function surface engineering of SnO2 nanoparticles. TBA+ ions improve the dispersion and stability of colloidal T-SnO2 nanoparticles and act as a bridge between the ETL and perovskite layer through the electrostatic interaction with anions, thus suppressing the charge recombination and reducing the energy loss. I- ions passivate oxygen vacancies of SnO2 nanoparticles but also halide vacancies of the perovskite layer. Furthermore, the conduction band edge of T-SnO2 is enhanced to match the energy alignment with the perovskite, which reduces the energy offset for electron transfer. As a result, the champion solar cell based on T-SnO2 presented a power conversion efficiency of 21.71% with a VOC of 1.15 V and negligible hysteresis, which are much higher than those of the reference device.

Perovskite large-scale solution manufacturing methods combined with relevant crystallization thermodynamics and kinetics, as well as challenges including stability, toxicity, and module cost issues towards commercialization are reviewed.

In this paper, ZnO nanorod-nanosheet hierarchical structures were fabricated using a facile method on zinc foil and used as flexible photoanodes in dye-sensitized solar cells (DSCs). Compared to nanorods (NRs) obtained by the dissolution-precipitation method, the nanorod-nanosheet (NR-NS) hierarchical structures obtained by a second-step homogeneous precipitation improved the performance of DSCs by increasing photocurrent density significantly. As a result, the power conversion efficiency of the devices based on such a NR-NS hierarchical structure reached up to 2.4% under 100 mW cm(-2) illumination condition. This represents an enhancement by 108% as compared to DSCs based on NR assembled nanoflowers, for which the efficiency was 1.1%. The enhancement of the photocurrent was due mainly to the much larger specific surface area and resulting dye-loading amount. The electron transport properties in this structure were also investigated by means of electrochemical impedance spectroscopy (EIS). Furthermore, the formation mechanism of the NR-NS hierarchical structures are discussed.

We report the phase transfer in heavy-metal-free ZnSe nanorods (NRs) from hexagonal wurtzite (WZ) to cubic zinc-blende (ZB) phases. This phase transformation is mediated by Cu(I) ions under thermal...

In this work, we reported a facile chemical passivation strategy for a ZnO mesoporous photoelectrode to improve the performance of a CdS/CdSe quantum dot co-sensitized solar cell (QDSC). The QDSC exhibited a record power conversion efficiency of 4.68%.