Yiheng Yue,Guocheng Pan,Jun Wan,Zhen Xiao,Yang Zhang,Shiqing Xu,Gongxun Bai
Mechanoluminescent (ML) materials offer significant potential for remote stress sensing and distribution. However, creating highly sensitive and responsive ML materials remains a challenge. In this study, mechanoluminescent semiconductor materials have been successfully prepared as Mn 2+ doped ZnS-SrZnOS heterojunction composites. These materials exhibit high-resolution stress distribution visualization and rapid response, captured via camera recording. Notably, they possess a low stress triggering threshold, reaching the KPa level, and respond within milliseconds. Furthermore, it was found that by adjusting the doping concentration of Mn 2+ within the heterojunction, the material utilizes its bimodal emission capability to manipulate the fluorescence shift and achieve optical anti-counterfeiting. The synthesis of smart films by combining the material with polydimethylsiloxane matrix had enabled the achievement of collision detection, information hiding and optical anti-counterfeiting. These results suggest that the prepared smart films have wide range of optical sensing applications.
Perovskite solar cells have developed rapidly in recent years as the third generation solar cells. In spite of the great improvement achieved, there still exist some issues such as undesired hysteresis and indispensable high temperature process. In this work, bulk heterojunction perovskite-phenyl-C 61 -butyric acid methyl ester solar cells have been prepared to diminish hysteresis using a facile two step spin-coating method. Furthermore, high quality tin oxide films are fabricated using pulse laser deposition technique at room temperature without any annealing procedure. The as fabricated tin oxide film is successfully applied in bulk heterojunction perovskite solar cells as a hole blocking layer. Bulk heterojunction devices based on room temperature tin oxide exhibit almost hysteresis-free characteristics with power conversion efficiency of 17.29% and 14.0% on rigid and flexible substrates , respectively.
Both bismuth and copper are non-toxic and earth-abundant elements suitable for lead-free halide perovskite-like photovoltaic devices. Here, we report a highly facile route for in-situ producing copper-bismuth-iodide (CuBiI 4 ) thin films directly on ITO substrate at room temperature, by utilizing a Bi-Cu alloy layer as precursor. X-ray diffraction and transmission electron microscopy (TEM) results verified the formation of well crystallized CuBiI 4 thin films with [222] orientation. The transient photovoltage (TPV) analysis revealed that the CuBiI 4 is an n-type semiconductor with a suitable band gap of ~1.81 eV, preferable to photoelectric conversion compared with CH 3 NH 3 PbI 3 . It is very interesting that the subsequent spin-coating process of the classical Spiro-MeOTAD organic solution with TBP and acetonitrile resulted in a dense and smooth CuBiI 4 :Spiro-MeOTAD bulk-heterojunction film. The preliminarily fabricated simple sandwich structures of ITO/CuBiI 4 :Spiro-MeOTAD/Au hybrid solar cell devices displayed efficient photovoltaic performance with the PCE up to 1.119% of the best sample. The room temperature direct metal surface elemental reaction (DMSER) method may provide a new insight for all-inorganic lead free perovskite-like A a B b X x compounds and high performance photovoltaic devices.