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Hot-carrier solar cells offer the potential for enhanced power conversion efficiency by tapping into the kinetic energy of hot carriers generated upon sunlight absorption. This involves using specially designed materials capable of efficiently extracting and utilizing the energy of these hot carriers to produce electrical power. Here, we observed such a hot carrier effect in hexamine doped methylammonium lead triiodide perovskite solar cells when exposed to 100 mW/cm2 of 5000 K white LED light. We discovered that these perovskite solar cells exhibited remarkable power conversion efficiency, reaching up to 54.22% with the Voc (open-circuit voltage) and Jsc (short-circuit current density) values were measured at 1.10 V and 54 mA/cm2, respectively. In comparison, under similar conditions but using a solar simulator, the power conversion efficiency remained below 20%. Our results suggest that the high PCE under white LED irradiation is due to the fine resonance between the light energy and perovskite band gap energy, enabling long carrier lifetime and then allowing massive photovoltaics process. These findings highlight the alternative to achieve hot carrier's perovskite solar cells and efficient energy generation by converting light energy into the wavelength match with the perovskite materials absorber energy band gap. [ABSTRACT FROM AUTHOR]

Silver nanowires (AgNWs) exhibit a good potential function as transparent conductive electrodes (TCEs) due to their excellent electrical conductivity and transparency. In addition, the ability to prepare the AgNWs with a variety of diameters and lengths, distribution concentration and availability of a wide range of deposition methods, such as spin-coating, spray-coating, or brush-painting, offer many possibilities of using TCEs based on AgNWs for specific applications. Here, we demonstrate a straightforward way to prepare AgNWs using a one-pot method and the AgNWs TCEs via spin-coating methods. The AgNWs thin film electrode with a diameter, length, and thickness of 80 nm, 45 µm, and 78 nm, respectively, give sheet resistance as low as 83.2 Ω/square. Meanwhile, the optical transmittance is as high as 92.8% at 550 nm. This produces a figure of merit value, i.e. the ratio between the transparency and the sheet resistance, as high as 11 × 10−3. The AgNW TCEs should find use in light-emitting diode and optical sensor applications. The transparent conducting electrode composed of Ag nanowires that exhibits excellent transparency and electrical properties are prepared via one-pot growth and spin-coating. [ABSTRACT FROM AUTHOR]

This study reports the performances of a single structured light-emitting diode (LED) devices based on polymer material poly(9,9-di- n -hexylfluorenyl-2,7-diyl) (PHF) mixed with various concentrations of perovskite oxide strontium titanate (SrTiO3) particles deposited as a composite PHF: SrTiO3 emitting layer. The performances of the single structured organic LED indium tin oxide (ITO)/PHF/aluminum (Al) device and the composite LED ITO/PHF: SrTiO3/Al devices were compared in terms of turn-on voltage and luminance intensity. By incorporating perovskite SrTiO3 particles into PHF emitting layer, the turn-on voltage of the device is significantly reduced from 11.25 V to 1.80 V and the luminance intensity increased from 57.7 cd/m2 to 609 cd/m2. The improvement of turn-on voltage and the electroluminescence spectrum of the composite devices were found to be dependent on the weight ratios of SrTiO3 content in the PHF emitting layer. [ABSTRACT FROM AUTHOR]

Abstract: White organic light emitting diode (OLED) devices with the structure ITO/PHF:rubrene/Al, in which PHF (poly(9,9-di-n-hexylfluorenyl-2,7-diyl)) is used as blue light emitting host and rubrene (5,6,11,12-tetraphenylnapthacene) as an orange dye dopant, have been fabricated. Indium tin oxide (ITO) coated-glass and aluminium were used as anode and cathode, respectively. The devices were fabricated with various rubrene-dopant to obtain a white light emission. The OLED device that composed of several concentrations of rubrene-doped PHF film was prepared in this study. It was found that the concentration of rubrene in the PHF-rubrene thin film matrix plays a key role in producing the white color emission. In a typical result, the device composed of 0.06 wt.% rubrene-dopant produced the white light emission with the Commission Internationale de L''Eclairage (CIE) coordinate of (0.30,0.33). The turn-on voltage and the brightness were found to be as low as 14.0 V and as high as 6540 cd/m2, respectively. The annealing technique at relatively low temperature (50 °C, 100 °C, and 150 °C) was then used to optimize the performance of the device. In a typical result, the turn-on voltage of the device could be successfully reduced and the brightness could be increased using the annealing technique. At an optimum condition, for example, annealed at 150 °C, the turn-on voltage as low as 8.0 V and the brightness as high as 9040 cd/m2 were obtained. The mechanism for the improvement of the device performance upon annealing will be discussed. [Copyright &y& Elsevier]