Charge recombination is an important factor that limits the cell efficiency of quantum dot sensitized solar cells (QDSSCs). Herein, we report a facile way to improve the cell performance of CdSe sensitized ZnO QDSSC by overcoating a thin layer of ZnSe on CdSe/ZnO film through a successive ionic layer adsorption and reaction (SILAR) procedure. Photovoltaic investigations indicate that ZnSe overcoating can increase photocurrent and photovoltage of the cell, resulting in significant enhancement of the cell efficiency, which is much better than the widely used traditional ZnS material. The superior role of ZnSe overcoating is ascribed to its large inhibition of charge recombination loss owing to its suitable band structure, efficient passivation of ZnO and CdSe QDs as well as its small lattice mismatch with CdSe that leads to the large decrease of surface/interface defects in CdSe/ZnO photoanode . This finding provides an alternative efficient way to enhance the cell performance of ZnO based QDSSC by suppressing the charge recombination.
High-performance organic photovoltaics (OPVs) are of great scientific and technological importance due to their potential large-scale industrial applications. Introducing semiconductor quantum dots has been proven to be an effective way to improve the power conversion efficiency (PCE) of OPVs. In this paper, we report a novel approach to fabricate atomically thin antimonene quantum sheets (AMQSs) possessing a uniform size (≈2.2 nm) via imidazolium ionic liquid-assisted exfoliation. In this method, the yield of AMQSs (1.1 mg mL−1) has been increased by nearly two orders of magnitude compared with that of previously reported methods. Furthermore, upon adding AMQSs into the light absorber in OPVs, the optimal device with 1.0 mg mL−1 AMQSs shows the highest PCE of 9.75%, resulting in over 25% enhancement in PCE compared to that of the reference device. It also leads to a noticeable enhancement in the short-circuit current density (Jsc) of 16.7% and the fill factor (FF) of 8.4%. The increased PCE is mainly due to the two-dimensional electronic structure of AMQSs that can enhance the light absorption, assist exciton dissociation and reduce charge recombination of OPVs. This work provides a new avenue toward mass production of two-dimensional quantum sheets and points to a new strategy for highly efficient OPVs.
You Liu,Fang Liu,Jungan Wang,Hongyan Huang,Suhao Yan,Song Gao,Lin Wang,Wei Huang,Tianshi Qin
Wide-bandgap photovoltaics (WBPV) could not only provide electrical energy by photoelectronic conversion of the invisible part of the solar spectrum, but also usually had the unique advantage of high open circuit voltage ( V oc). In this work, we reported a novel HTM based on tetrakis (N-phenothiazine) Spirobifluorene (Spiro-PT), its HOMO energy level could be well matched with MAPbBr 3 perovskite HOMO energy level. This HTM could effectively suppress nonradiative recombination, which leads to an increase in the photovoltage of WBPV to more than 1.41 V. As a result, the n-i-p mesoscopic structured WBPV achieved a champion PCE of 7.36% as well as excellent operational stability exhibiting 91% of initial efficiency after 500 h continuous illumination without encapsulation. Based on the high V oc of the MAPbBr 3 /Spiro-PT device, the photovoltaic electrochromic device showed a response speed (the average coloring time was 40 s and the bleaching time was 272 s) and high average visible light transmittance contrast (about 37% in 450–780 nm), the corresponding electrochromic device with maximum dynamic contrast up to 46% at 600 nm between bleached and colored states. This WBPV-powered electrochromic system could provide a pathway towards stand-alone smart window technique for future energy-saving buildings.
危险品化学品经营许可证（带存储）