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Nanographenes for Renewable Energy
Published in Rakesh K. Sindhu, Mansi Chitkara, Inderjeet Singh Sandhu, Nanotechnology, 2021
Parth Malik, Showkat Hassan Mir, Rachna Gupta, Tapan K. Mukherjee
The emergence of NMs has catalyzed the feasibility of manifold novel technologies useful for the society. Presently, we are at the initial stage of the development of a whole new regime of two-dimensional materials. Among the several two-dimensional NMs investigated for their better structural and energy-driven applications, some entities include graphene [1, 44], hexagonal boron nitride (BN) [57], transition metal dichalcogenides [58–61], MXenes [62, 63], bismuth telluride ( Bi2Te3 ), bismuth selenide ( Bi2Se3 ), silicones [64], phosphorene [65, 66], antimonene [67], and graphyne [68, 69]. Graphene is perhaps the most researched one out of these, due to its unique properties. It is being investigated with considerable interest for its manifold unconventional attributes such as carrier mobility, mechanical strength, thermal conductivity (1500 and 5000 W/m·K), and SA (2630 m2/g), till date unnoticed in any other two-dimensional material [70–73]. These uncommon and splendid material properties of graphene owe their existence to a constitutional strong bonding between the hexagonal geometry of carbons [73] (Fig. 3.4).
Temporal and amplitude modulation at C-band region using Bi2Te3-based optical modulator
Published in Journal of Modern Optics, 2020
Harith Ahmad, Norazriena Yusoff, Hwee San Lim, Mohd. Zubir Mat Jafri, Mohd. Zamani Zulkifli, Zian Cheak Tiu
Figure 3(a) shows the nonlinear optical absorbance of the few-layers thick Bi2Te3 flakes investigated obtained using the balanced twin-detector method. For this measurement, a Menlo Systems ELMO femtosecond erbium-doped fibre laser (EDFL) is used as a pulsed 1564 nm source with the repetition rate of 100 MHz and a pulse width of 2.88 ps. The obtained measurements are fitted into the formula as shown in Equation (1): where α(I), αs, αns, I and Isat are the intensity-dependent absorption coefficient, saturable loss or modulation depth, non-saturable loss, pump light intensity and saturation intensity respectively. From the fitted curve, a modulation depth of 7.7% and saturation intensity of 1.47 kW/cm2 is computed. These values are comparable to those reported in other literature for other TI materials such as bismuth selenide (Bi2Se3) [29] and antimony telluride (Sb2Te3) [30,31]. The linear optical transmittance spectrum of the few-layers thick Bi2Te3 flakes is given in Figure 3(b) and is obtained using a white light source and an optical spectrum analyser (OSA). From the measured spectrum of 1400–1600 nm, it can be seen that the Bi2Te3 sample exhibits featureless linear absorbance with a transmission of about 70.58% at the region centred at 1561 nm.
Annealing induced transformations in structural and optical properties of Ge30Se70−xBix thin films
Published in Phase Transitions, 2019
Adyasha Aparimita, R. Naik, C. Sripan, R. Ganesan
For the films at annealing temperature 250°C, a small peak comes at 2θ = 29.29° for both Ge30Se55Bi15 and Ge30Se50Bi20 which shows the Bismuth Selenide (BiSe) phase with the plane (0 0 8) (JCPDS Card no- 81- 0834). In case of Ge30Se55Bi15, two secondary peaks are observed at 2θ = 25.121° and 2θ = 43.68° indicating Bi2Se3 peaks in plane (1 0 2) and (1 1 2), respectively, (JCPDS Card no- 82-2442).