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In addition to device flexibility, the retentivity performance of photoelectric materials after an extreme reverse-bending process is intrinsically important and desirable for next-generation advan...

The transfer and recombination of photoinduced charge carriers play the crucial roles in a photoelectric conversion system. In this work, the Ag2S/fluorine-doped tinoxide (FTO) was used as the plat...

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 (CuBiI4) 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 CuBiI4 thin films with [222] orientation. The transient photovoltage (TPV) analysis revealed that the CuBiI4 is an n-type semiconductor with a suitable band gap of ~1.81 eV, preferable to photoelectric conversion compared with CH3NH3PbI3. 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 CuBiI4:Spiro-MeOTAD bulk-heterojunction film. The preliminarily fabricated simple sandwich structures of ITO/CuBiI4: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 AaBbXx compounds and high performance photovoltaic devices.

CdSe semiconductor nano crystals (NCs) and Polyaniline (PAni) are mixed uniformly to prepare CdSe NCs/PAni complex. PAni can quench the fluorescent signal of CdSe NCs. The fluorescent intensity of CdSe NCs/PAni complex is related to the size of CdSe NCs and concentration of PAni. Ultraviolet visual (UV-Vis) absorption spectra and fluorescence spectra are employed to analysis the quenching phenomenon. The mechanism of fluorescence quench is dependent on two factors: on one hand, the FÖrster resonance energy transfer conducts from CdSe to PAni; on the other hand, PAni can intercept the electron charge of CdSe and lead to the interruption of radiative recombination.

Waveguide grating filter with an antireflective surface is designed by using the equivalent homogeneous thin-film model. The spectral properties are investigated by using the rigorous method based on the calculated parameters. It is shown that the equivalent homogeneous thin-film model may provide a reliable approximation in estimating the resonance locations of the filters even for the surface-relief grating structure. The validity of the design model decreases with the increase of the refractive index contrast of the grating layer for a fixed grating filling factor.

Wideband reflector and bandpass filter are obtained by using a Ge subwavelength periodic membrane with the thickness kept constant at 3.20 μm. The strong refractive-index modulation of the Ge subwavelength periodic membrane yields increased bandwidth of the leaky mode resonances, thus the excitation of the leaky mode resonances TE 1,1 , TE 2,1 , and TE 3,0 may interact to form a broad reflection band or a transmission passband near λ=10.60 μm.

In this paper, a new design of a type of mechanically tunable transmission filter is theoretically presented by using double-subwavelength periodic membrane structures with an air gap. A strongly modulated periodic membrane provides a broad reflection band due to the guided mode resonance (GMR) effect. The interaction between the edges of the GMR and the broad reflection band creates the tunable transmission passbands. Stronger and weaker evanescent couplings between the two periodic membranes show a wide range of tunability. The overetching error should be avoided in both cases of symmetrical and unsymmetrical structures. An effective control of the tunability with good spectral properties can be obtained in the weaker evanescent coupling region due to the negligible lateral alignment condition. The localization of the electric field is mainly confined in the periodic membranes as the thickness of the air gap is smaller, while the energy of the electric field is mainly localized in the air cavity as the thickness of the air gap is larger. Thus the influence of the lateral shift of a periodic membrane on the spectral properties is different due to their different coupling mechanisms in both cases.