Essay On Dye Sensitized Solar Cells

Photoluminescence (PL) spectra of the as-prepared samples were investigated to understand the transfer, separation, and recombination of photo-generated electrons and holes pairs [34]. In general, lower PL intensity indicates a lower recombination rate of charge carries, leading to higher photocatalytic activity [35]. The room temperature PL spectra (excitation at 330 nm) of ZnO and Ag@ZnO CSNS are depicted in Fig. 4. It has been observed that ZnO shows a near band edge emission band centered at 378 nm and no emission band in the visible region. In the case of Ag@ZnO CSNS, the intensity of PL spectrum is significantly lowered compared to that of the ZnO. The distinct quenching of the emission was distinctly observed from the Ag@ZnO CSNS,

In this communications, PEDOT: PPS electrode is employed as a counter electrode in a dye-sensitized solar cell for low-cost photosensor applications. TiO2 nanomaterial is used as photoanode. The structure of the PEDOT: PPS film was investigated by atomic force microscope. This DSSC behaves like Schottky diode at the dark condition. The photovoltaic behavior was studied in the light intensity range 5 - 130 mW/cm-2. This cell has a stable fill factor of about 0.5 for all the studied illumination intensity range. The linear photo-response of the current suggests that new designed DSSC with the polymeric counter electrode is a promising device for the low-cost photosensor. The cell shows capacitance inversion from positive to

Photocatalysis is one of the clean and renewable technologies, utilizes naturally enormous abundant, clean and safe solar power. The cheap solar energy harnessing is one of the most exciting features to gain significant attention toward photocatalysis direction. Titanium oxide-based photocatalyst has shown considerable interest since the discovery because of the excellent properties such as chemical and photostability, eco-friendly nature and high catalytic reactivity.2,3 TiO2 photocatalysts have been widely engaged in various photocatalytic applications such as water and air cleaning, self-cleaning and anti-fogging TiO2 coated glasses, tiles, and shelters. TiO2 only generates electron-hole pairs under UV light, which are responsible for the photocatalytic reaction. There are numerous investigations have been done to alter the TiO2 structures to absorb visible lights. The strategy includes adding noble metals4, cations5, non-metals6, and metal oxides7 through various methods such as sol-gel8, physical ion-implantation methods,

Six AP chemistry students, including myself, were selected to do research at Rensselaer Polytechnic Institute with Dr. Peter Dinolfo last Summer. At RPI, Dr. Dinolfo and two of his graduate students helped us connect our knowledge of AP chemistry, to the creation of our very own Dye Sensitized Solar Cells (DSSCs).

As more electrons were introduced, the net carrier concentration started to decrease until the electrons became the majority carriers. This process may explain the change of conduction type and carrier concentrations. The carrier mobility, however, decreased gradually from 6.52 cm2/V*s to 4.30 cm2/V*s as cobalt doping increased from 2 at% to 6 at%. This phenomenon could be explained as the decreased mean free path of charged carriers because of the larger size of the incorporated cobalt ions than the original iron ions. After switching to n-type, the increasing carrier concentration may also contributed to the reducing of carrier mobility. As a consequence, cobalt doping served well as an n-type dopant after 3 at% doping level.

There are many current challenges to perovskite solar cells. One of these is their long-term stability. Typical silicon solar panels are usually guaranteed to last up to 20 years. However, perovskite solar cells only last for months. Extreme temperatures, humidity, light levels, and weather changes all cause perovskite cells to decompose. In particular, moisture is a problem as perovskite reacts to water forming hydrates; the crystal structures are altered in a way so that the perovskites cannot absorb visible light anymore, and thus, rendering them useless. There has been progress; cells had once only lasted minutes but now can last a few months, but in order to achieve this team’s goal of having

My career in energy technology and surface chemistry began in 2012, when I started my master’s coursework and research in electrochemistry at the University of Louisville’s Department of Chemistry. Since then I have developed an extensive skillset, focusing mainly on the development and usage of semiconductor materials such as titanium oxide (TiO2), tin-oxide (SnO2), birnessite-manganese oxide (b-MnO2), and neodymium oxide (Nd2O3). I have extensively studied the photophysics and photochemistry of energetic nanomaterials in order to explore the fundamentals of charge transfer dynamics, catalytic properties, and mechanisms for the conversion of solar energy to electric energy to produce renewable electricity. Later in my doctoral

An effective way for promoting photocatalytic activity of a semiconductor is doping of rare earth metal nanoparticles (NPs) onto it. Zinc oxide and Lanthanum doped Zinc oxide nanoparticles were synthesized by modifying the gel-combustion method. It was found that La can greatly enhance the cytotoxicity and photocatalytic activity of ZnO nanoparticles towards various cell lines and paracetamol drug. These nanoparticles were characterized by various spectroscopic and other techniques which clearly revealed the presence of lanthanum ions. The UV-vis spectroscopy displayed the absorption edge shifts towards the visible region after doping with La which is extremely favorable for absorbing the visible light. We compared the enhancing effect of La ions and found that La doped ZnO nanoparticles is more effective than ZnO nanoparticles in promoting the generation of hydroxyl radicals, holes and the photocatalytic activity of ZnO. Finally, the results of these studies provide a concise viewpoint in this important research area and specifically propose further research opportunities in optimizing the photocatalytic performance of La doped ZnO nanoparticles and widening the scope of their potential photocatalytic and biomedical applications.

In this work, their substrates are Pilkington TEC-15 (SnO2:F/SnO2) glass plates. And before thin film deposition, the glass plate would be cleaned by standard cleaning procedure. And Darmstadt Integrated System for SOLarcell research(DAISY-SOL) was used to determine the thin film deposition of the CdS and CdTe individually. And the CdS deposition was double layer structure, the first layer was deposited at high temperature in range of 520 to 540 °C, while the second layer was deposited at 250 °C. And for the CdTe layer, was deposited under vacuum condition, in order to minimize the likelihood of pinhole formation. And it also formed 2 layers under 490-530 °C and 350 °C individually [2].

This can be attributed to the fact that as the current is directly proportional to the flux, the magnitude of the current should be fast at faster scan rate and slow at slower scan rates.40 The CV curves reveal that the maximum current density and an enhanced capacitive area were observed for the nanocomposites ZnSnO2@G. This observation can be explained based on the fact that graphene with its 2D structures exhibits enhanced conductivity, higher surface area, and better capacitive behavior as compared to CNT. However, the Zn-doped nanocomposites have enhanced current densities as compared to SnO2-based nanocomposites, probably because of two reasons viz. First, the incorporation of Zn2+ ions as dopants decreases the size, and second, the substitution of the Zn2+ ions for the Sn4+ ions modifies the surface and forms more oxygen vacancies for charging compensation. Thus, the CV curve confirms the successful interaction between the metal oxides and graphitic forms, as also expected from the surface area and FESEM morphologies.

The focus of this section will be on the growth mechanism, characterization and applications of TiO2 nanowires. Three growth mechanism will be reviewed are sol-gel, direct oxidation, and hydrothermal. The characterization of TiO2 nanowires are analyzed by the SEM, TEM, and Ramen spectroscopy. The current and future application of TiO2 will be discussed in the last part of this section. Three applications of TiO2 nanowires are explored in this survey: (1) photocatalytic (2) gas sensing (3) dye-sensitized solar cell.

Thus, numbers of articles devoted to ZnO photoelectrode with the aim of enhancing efficiency by reducing the charge recombination, and improving electrical/optical performance [9-12]. In this regard, doping is the most advantageous approach to modify ZnO structure. Different kind of metals such as lanthanum [13] aluminum [14], tin [15], magnesium [16], titanium [17] has been widely investigated in ZnO photoelectrode for improving the performance. Moreover, earlier reports on the DSSC have proven that the active area is directly proportional to the power conversion efficiency [18]. Therefore, we attempted to incorporate indium to improve above cited aspects with an idea working area (0.25cm2) of prototype DSSC. Indium (In3+) chosen as dopant, because it has a noteworthy contribution in transparent conducting oxide materials and much work devoted in indium doped ZnO as a transparent conducting oxide film [19-20]. Owing to their remarkable properties such as high electronegativity, minute native lattice distortion with preferable chemical stability make indium as suitable donor than other elements for finding high quality ZnO based transparent conducting oxide with excellent conductivity in DSSCs [21]. Rama Krishna Chava et al. reports the trivalent indium substitution in zinc oxide nanoparticles enhance the carrier concentration

From the help of Kubelka-Munk (K-M) theory reflectance data was convert absorption mode [27]. As shown in figure 7 the as-prepared CuO nanostructures with different ratio of citric acid exhibit different sensitivities to visible light, the absorption edge is shifted to shorter wavelength with compact size and altered morphology. Our results point out not only the size but also the morphology of the CuO nanocrystals affects the bandgap. It is quite observable from the figure 7b that SP0.10A exhibits the hogher absorption properties in the visible region. Bhaumik, et al 2016 [28] reported the increase in absorption is highly desirable for better efficiency of a solar cell. Therefore the SP0.10A sample exhibits the strongest absorbance and has a uniform flower-shaped CuO crystal thus; we can say that the sample may be ideal solar absorbers.

ZnO-based materials have emerged as a promising material for transparent electrodes in solar cell applications and nowadays much effort has been devoted to investigate the dye-sensitized solar cell characterizes of ZnO thin films [4]. Due to its large binding energy (60meV), wide band gap (3.37eV) [1], high electron Hall mobility (200 cm2 Vs−1) and easy synthesis and assembly methods, the utilization of ZnO has covered a vest rang of solar photovoltaic [5-8]. Dye-sensitized solar cell (DSSC) photoanodes prepared via different ZnO nanostructures has achieved considerably enhancement in power conversion efficiency (η) as compared to simple ZnO nanoparticle mesoporous films. Up to now the highest η ~8.03 was reported by air plasma treatment

Abstract: The current energy situation with fossil fuels as the main source of the world’s energy has two main flaws: fossil fuels contribute to global warming via the greenhouse effect and they are limited in the quantity that remains. Solar power solves both of these problems and can be captured by utilizing photovoltaic cells. However, photovoltaic cells have their own drawbacks due to their high costs of installation and maintenance.