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We present the fabrication and electrical response of a flexible prototype supercapacitor based on activated carbon electrodes obtained from bamboo (Guadua angustifolia Kunth) as precursor. The supercapacitor prototype was fabricated by using a multilayer configuration method; activated carbon electrodes were impregnated with 0.5 M H2SO4 as electrolyte and filter paper was used as separator. Carbon activation was performed by using NaOH and KOH solutions. Activated carbon electrodes were characterized by adsorption isotherms, cyclic voltammetry, and SEM techniques. Electrical response was found by using charge‐discharge curves. Through adsorption isotherms analysis, we found a surface area of 408 and 309 m2 g−1 for the activated carbon with NaOH and KOH, respectively. From the electrical characterization analysis of the supercapacitor device, we obtained 0.92 F for the maximum capacitance value by using 0.5 V as fixed value in the bias voltage. Also, we proposed an equivalent electrical circuit for the supercapacitor prototype. This capacitance value is comparable with the capacitance values exhibited by rigid commercial supercapacitor, such as Dinacap and capacitor Capattery Gold, among others. Finally, these results suggest that the activated carbon from bamboo can be used in flexible electronic applications.

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We analyzed the free to acceptor (e-A) photoluminescence transition on a GaAs:Ge sample using the hot carrier temperature and the Kane's DOS. This latter temperature was calculated by the spectra largest energy tail. While the lattice temperature was put in the e-A Eagles' shape equation, the fitting was poor but if the modified line was put into the equation, the fitting was better. So, the ionization impurity energy, the band gap, the Fermi level and the band tail can be measured with a better precision than the measurements traditionally made with this method, Additional information about phonons participant can be obtained. In conclusion, the hot carrier temperature and the density of states due to the impurity concentration should be used in the e-A transition photoluminescence analysis.

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Photoreflectance and photoluminescence study of Ga 0.76 In 0.24 Sb / GaSb single quantum wells: Band structure and thermal quenching of photoluminescence Composition and carrier-concentration dependence of the electronic structure of In y Ga 1 − y As 1 − x N x films with nitrogen mole fraction of less than 0.012 J. Appl. Phys. 98, 093714 (2005); 10.1063/1.2127126Modeling and analysis of photomodulated reflectance and double crystal x-ray diffraction measurements of tensilely strained InGaAs/InGaAsP quantum well structures

We analyzed the photoluminescence (PL) spectra on heavily doped GaAs:Sn samples by Kane's theory including a Lorentzian, a Gaussian and the hot carrier temperature. The band gap, the Fermi level, and the Urbach tail were the fitting parameters. Good results were obtained when the theoretical and experimental values were compared for the three parameters. The Urbach energy magnitude and the topological disorder parameter increased when the impurity concentration augment. The average phononic participation was very close with the tabulated values. New information about a shoulder in the high energy side was obtained, too.